GOODCARE Isabgol
Nature's best solution! An age-old ayurvedic remedy for constipation and allied problems.Most people do not get enough fibre in their diet. This fibre deficiency results in record number of overweight people, above normal cholesterol level, chronic indigestion and greater occurrence of colon cancer. Even health and diet conscious individuals are amazed to find themselves lacking in fibres.Goodcare Isabgol is sourced from the world's best sources of pure psyllium husk, separated by the process of milling.One teaspoon daily at bedtime forms bulk in your digestive system, which in turn smoothens the way for releasing toxic waste from your body.It helps regulate your daily bowel movement and reduces the risk of heart attacks by decreasing serum cholesterol through proper excretion of bile acids. One or two teaspoon full before meals will reduce your consumption of fat and calories.May be taken with milk, juice or water.Goodcare Isabgol has a remarkable effect on the gastro intestinal system.It is a naturally healthy fibre and is not absorbed in the intestine. It has no known interaction with other drugs, and does not interfere with the absorption of vitamin and minerals.Isabgol is internationally acclaimed as the best agent that relievesconstipation with absolutely no side effects.
What Isabgol does?
A natural remedy for constipation, regulates bowel functions.
A bulk forming laxative
Help reduce risk of heart attack by decreasing serum cholesterolthrough proper excretion of bile acids.
Consumed with water prior to meals, reduces constipation of fat and calorie.
Help reduce risk of heart attack by decreasing serum cholesterol throughproper excretion of bile acids
Goodcare Isabgol is -
Non-habit forming.
Contains no artificial chemicals
Extremely safe for all ages
It has no side effects.
It is 100% safe and natural.
Dosage :One teaspoon with milk or water at bedtime. Maybe altered according to individual requirement.
No post box delivery for International shipment
For USA customers onlyThere is a requirement for every USA consignment to be registered by the FDA. We will comply with this registration to facilitate the delivery to your destination. USA customers may have to pay an import custom duty for each consignment to the US authority.The total value of purchase should not be less than Rs 250.
Isabgol (H)
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Monday, May 21, 2007
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medicinal plants
Periwinkle.
Description and Natural History of the Periwinkle Catharanthus roseus is known as the common or Madagascar periwinkle, though its name and classification may be contradictory in some literature because this plant was formerly classified as the species Vinca rosea, Lochnera rosea and Ammocallis rosea. Furthermore, lesser periwinkle (Vinca minor) may also be called common periwinkle. Both species are also known as myrtle.
In any case, this periwinkle is a perennial, evergreen herb in the dogbane family (Apocynaceae) that was originally native to the island of Madagascar. It has been widely cultivated for hundreds of years and can now be found growing wild in most warm regions of the world, including the Southern U.S. The plants grow one or two feet high, have glossy, dark green leaves (1-2 inches long) and flowers all summer long. The blooms of the natural wild plants are a pale pink with a purple "eye" in their centers, but horticulturists have developed varieties with colors ranging from white to hot pink to purple.
The plant has historically been used to treat a wide assortment of diseases. It was used as a folk remedy for diabetes in Europe for centuries. In India, juice from the leaves was used to treat wasp stings. In Hawaii, the plant was boiled to make a poultice to stop bleeding. In China, it was used as an astringent, diuretic and cough remedy. In Central and South America, it was used as a homemade cold remedy to ease lung congestion and inflammation and sore throats. Throughout the Caribbean, an extract from the flowers was used to make a solution to treat eye irritation and infections.
It also had a reputation as a magic plant; Europeans thought it could ward off evil spirits, and the French referred to it as "violet of the sorcerers."
Western researchers finally noticed the plant in the 1950's when they learned of a tea Jamaicans were drinking to treat diabetes. They discovered the plant contains a motherlode of useful alkaloids (70 in all at last count). Some, such as catharanthine, leurosine sulphate, lochnerine, tetrahydroalstonine, vindoline and vindolinine lower blood sugar levels (thus easing the symptoms of diabetes). Others lower blood pressure, others act as hemostatics (arrest bleeding) and two others, vincristine and vinblastine, have anticancer properties. Periwinkles also contain the alkaloids reserpine and serpentine, which are powerful tranquilizers.
Because the alkaloids in this plant can have serious side effects such as nausea and hair loss, it is not recommended that people attempt to medicate themselves with periwinkles.
For more information, visit:
HREF="http://www.lycaeum.org/graphics/organics/html/catharanthus.html">Catharanthus
Growing Instructions -->
Periwinkle Diseases
References:
Dobelis, Inge N., ed. 1989. Magic and Medicine of Plants. Pleasantville, NY, Reader's Digest Books.
Heywood, V.H., ed. 1993. Flowering Plants of the World. New York, NY, Oxford University Press.
Simpson, Beryl Brintnall and Molly Conner-Ogorzaly. 1986. Economic Botany: Plants in Our World. New York, NY, McGraw-Hill Publishing Co.
Periwinkle
Printer Friendly Version
Periwinkle is also called vinca or myrtle. Of the 12 species of periwinkle, two are popular ground- covers. All species have opposite leaves and single flowers. The perennial periwinkle should not be confused with the bedding plant, Madagascar periwinkle (Catharanthus roseus).
DESCRIPTION
Periwinkle (Vinca minor) is an excellent evergreen groundcover with dark green foliage. Oblong to ovate leaves are opposite, simple, ½ to 2 inches long, glossy, with a short petiole. They exude a milky juice when broken. Flowers are purple, blue or white depending on the cultivar. Plants bloom in April and sometimes again in the fall. Vinca minor grows about 6 inches tall, spreading in all directions by sending out long trailing and rooting shoots, which make new plants.
Vinca major or large periwinkle is a larger, more aggressive species than V. minor. Leaves are up to 3 inches long. The blue, funnel-shaped flowers are 1 to 2 inches in diameter. They are borne in abundance in early spring and sporadically throughout the summer. Large periwinkle spreads rapidly and will mound up to 2 feet. Non-flowering stems root at the tips where they touch the ground.
LANDSCAPE USE
The trailing, arching stems that root where they touch the soil make these evergreen plants useful as groundcovers, for erosion control on banks, or for cascading from window boxes or planters. Periwinkle grows well under trees and shrubs, on shaded slopes or on the north side of buildings. Spring-flowering bulbs interplanted with periwinkle will lend color and interest to the groundcover planting. Daffodils are particularly well-suited since they bloom with periwinkle and do not require frequent division.
CULTIVATION
Periwinkle prefers shade but will grow well in full sun. The foliage color is richer green in partial shade, but more flowers are produced in the sun. Rooted cuttings or established plants are normally spaced from 12 to 18 inches apart. At a 6-inch spacing periwinkle will completely cover an area in one year. Plant whenever the soil is workable and provide sufficient water, especially when planting in summer. Weeding and mulching are required on a regular basis until the groundcover fills in the planted area. Periwinkle prefers moist, well-drained soil, abundantly supplied with organic matter, but it is tolerant of a wide variety of soil conditions. Fertilize only when necessary, preferably in the spring with a complete fertilizer such as 10-10-10 at a rate of 6 to 8 pounds per 1,000 square feet. Occasionally shear plants close to the ground to encourage new growth. Propagate by taking tip cuttings of non-flowering stems in late spring or divide throughout the season.
CULTIVARS OF PERIWINKLE
‘Alba’ has white flowers.
‘Atropurpurea’ has purple flowers.
‘Bowles Variety’ has blue flowers and grows vigorously in clumps.
‘Variegata’ has blue flowers and leaves variegated with rich yellow.
‘Flore Pleno’ has double, purple flowers.
‘Alboplena’ bears white, double flowers.
‘Jekyll’s White’ has single, pure white flowers and is more floriferous than ‘Alba.’
‘Sterling Silver’ bears dark blue flowers and foliage with white margins.
CULTIVARS OF LARGE PERIWINKLE
‘Alba’ has white flowers
‘Pubescens’ bears more pubescent leaves than the species and red-purple flowers with narrow petals.
‘Reticulata’ has foliage netted with yellow lines.
‘Variegata’ has creamy white blotches on the leaves. Flowers are blue and plants are sometimes known as ‘Elegantissima.’
PROBLEMS
Periwinkle is susceptible to dieback (plants wilt and "die back" to the ground), caused by fungal diseases. Cankers, which are sunken, woundlike lesions, may be visible on the stem near the groundline. Fungal leaf spots occasionally occur and look like brown circular-to-oval spots on the leaves. Infected leaves should be sheared off and discarded. To reduce fungal infection, avoid overhead irrigation. Chemical control is seldom necessary.
Prepared by Marjan Kluepfel, HGIC Information Specialist, and Bob Polomski, Extension Consumer Horticulturist, Clemson University.
This information is supplied with the understanding that no discrimination is intended and no endorsement by the Clemson University Cooperative Extension Service is implied. All recommendations are for South Carolina conditions and may not apply to other areas. Use pesticides only according to the directions on the label. All recommendations for pesticide use are for South Carolina only and were legal at the time of publication, but the status of registration and use patterns are subject to change by action of state and federal regulatory agencies. Follow all directions, precautions and restrictions that are listed. (New 6/99).
The Clemson University Cooperative Extension Service offers its programs to people of all ages, regardless of race, color, sex, religion, national origin, disability, political beliefs, sexual orientation, marital or family status and is an equal opportunity employer.Clemson University Cooperating with U.S. Department of Agriculture, South Carolina Counties, Extension Service, Clemson, South Carolina. Issued in Furtherance of Cooperative Extension Work in Agriculture and Home Economics, Acts of May 8 and June 30, 1914Public Service Activities
Description and Natural History of the Periwinkle Catharanthus roseus is known as the common or Madagascar periwinkle, though its name and classification may be contradictory in some literature because this plant was formerly classified as the species Vinca rosea, Lochnera rosea and Ammocallis rosea. Furthermore, lesser periwinkle (Vinca minor) may also be called common periwinkle. Both species are also known as myrtle.
In any case, this periwinkle is a perennial, evergreen herb in the dogbane family (Apocynaceae) that was originally native to the island of Madagascar. It has been widely cultivated for hundreds of years and can now be found growing wild in most warm regions of the world, including the Southern U.S. The plants grow one or two feet high, have glossy, dark green leaves (1-2 inches long) and flowers all summer long. The blooms of the natural wild plants are a pale pink with a purple "eye" in their centers, but horticulturists have developed varieties with colors ranging from white to hot pink to purple.
The plant has historically been used to treat a wide assortment of diseases. It was used as a folk remedy for diabetes in Europe for centuries. In India, juice from the leaves was used to treat wasp stings. In Hawaii, the plant was boiled to make a poultice to stop bleeding. In China, it was used as an astringent, diuretic and cough remedy. In Central and South America, it was used as a homemade cold remedy to ease lung congestion and inflammation and sore throats. Throughout the Caribbean, an extract from the flowers was used to make a solution to treat eye irritation and infections.
It also had a reputation as a magic plant; Europeans thought it could ward off evil spirits, and the French referred to it as "violet of the sorcerers."
Western researchers finally noticed the plant in the 1950's when they learned of a tea Jamaicans were drinking to treat diabetes. They discovered the plant contains a motherlode of useful alkaloids (70 in all at last count). Some, such as catharanthine, leurosine sulphate, lochnerine, tetrahydroalstonine, vindoline and vindolinine lower blood sugar levels (thus easing the symptoms of diabetes). Others lower blood pressure, others act as hemostatics (arrest bleeding) and two others, vincristine and vinblastine, have anticancer properties. Periwinkles also contain the alkaloids reserpine and serpentine, which are powerful tranquilizers.
Because the alkaloids in this plant can have serious side effects such as nausea and hair loss, it is not recommended that people attempt to medicate themselves with periwinkles.
For more information, visit:
HREF="http://www.lycaeum.org/graphics/organics/html/catharanthus.html">Catharanthus
Growing Instructions -->
Periwinkle Diseases
References:
Dobelis, Inge N., ed. 1989. Magic and Medicine of Plants. Pleasantville, NY, Reader's Digest Books.
Heywood, V.H., ed. 1993. Flowering Plants of the World. New York, NY, Oxford University Press.
Simpson, Beryl Brintnall and Molly Conner-Ogorzaly. 1986. Economic Botany: Plants in Our World. New York, NY, McGraw-Hill Publishing Co.
Periwinkle
Printer Friendly Version
Periwinkle is also called vinca or myrtle. Of the 12 species of periwinkle, two are popular ground- covers. All species have opposite leaves and single flowers. The perennial periwinkle should not be confused with the bedding plant, Madagascar periwinkle (Catharanthus roseus).
DESCRIPTION
Periwinkle (Vinca minor) is an excellent evergreen groundcover with dark green foliage. Oblong to ovate leaves are opposite, simple, ½ to 2 inches long, glossy, with a short petiole. They exude a milky juice when broken. Flowers are purple, blue or white depending on the cultivar. Plants bloom in April and sometimes again in the fall. Vinca minor grows about 6 inches tall, spreading in all directions by sending out long trailing and rooting shoots, which make new plants.
Vinca major or large periwinkle is a larger, more aggressive species than V. minor. Leaves are up to 3 inches long. The blue, funnel-shaped flowers are 1 to 2 inches in diameter. They are borne in abundance in early spring and sporadically throughout the summer. Large periwinkle spreads rapidly and will mound up to 2 feet. Non-flowering stems root at the tips where they touch the ground.
LANDSCAPE USE
The trailing, arching stems that root where they touch the soil make these evergreen plants useful as groundcovers, for erosion control on banks, or for cascading from window boxes or planters. Periwinkle grows well under trees and shrubs, on shaded slopes or on the north side of buildings. Spring-flowering bulbs interplanted with periwinkle will lend color and interest to the groundcover planting. Daffodils are particularly well-suited since they bloom with periwinkle and do not require frequent division.
CULTIVATION
Periwinkle prefers shade but will grow well in full sun. The foliage color is richer green in partial shade, but more flowers are produced in the sun. Rooted cuttings or established plants are normally spaced from 12 to 18 inches apart. At a 6-inch spacing periwinkle will completely cover an area in one year. Plant whenever the soil is workable and provide sufficient water, especially when planting in summer. Weeding and mulching are required on a regular basis until the groundcover fills in the planted area. Periwinkle prefers moist, well-drained soil, abundantly supplied with organic matter, but it is tolerant of a wide variety of soil conditions. Fertilize only when necessary, preferably in the spring with a complete fertilizer such as 10-10-10 at a rate of 6 to 8 pounds per 1,000 square feet. Occasionally shear plants close to the ground to encourage new growth. Propagate by taking tip cuttings of non-flowering stems in late spring or divide throughout the season.
CULTIVARS OF PERIWINKLE
‘Alba’ has white flowers.
‘Atropurpurea’ has purple flowers.
‘Bowles Variety’ has blue flowers and grows vigorously in clumps.
‘Variegata’ has blue flowers and leaves variegated with rich yellow.
‘Flore Pleno’ has double, purple flowers.
‘Alboplena’ bears white, double flowers.
‘Jekyll’s White’ has single, pure white flowers and is more floriferous than ‘Alba.’
‘Sterling Silver’ bears dark blue flowers and foliage with white margins.
CULTIVARS OF LARGE PERIWINKLE
‘Alba’ has white flowers
‘Pubescens’ bears more pubescent leaves than the species and red-purple flowers with narrow petals.
‘Reticulata’ has foliage netted with yellow lines.
‘Variegata’ has creamy white blotches on the leaves. Flowers are blue and plants are sometimes known as ‘Elegantissima.’
PROBLEMS
Periwinkle is susceptible to dieback (plants wilt and "die back" to the ground), caused by fungal diseases. Cankers, which are sunken, woundlike lesions, may be visible on the stem near the groundline. Fungal leaf spots occasionally occur and look like brown circular-to-oval spots on the leaves. Infected leaves should be sheared off and discarded. To reduce fungal infection, avoid overhead irrigation. Chemical control is seldom necessary.
Prepared by Marjan Kluepfel, HGIC Information Specialist, and Bob Polomski, Extension Consumer Horticulturist, Clemson University.
This information is supplied with the understanding that no discrimination is intended and no endorsement by the Clemson University Cooperative Extension Service is implied. All recommendations are for South Carolina conditions and may not apply to other areas. Use pesticides only according to the directions on the label. All recommendations for pesticide use are for South Carolina only and were legal at the time of publication, but the status of registration and use patterns are subject to change by action of state and federal regulatory agencies. Follow all directions, precautions and restrictions that are listed. (New 6/99).
The Clemson University Cooperative Extension Service offers its programs to people of all ages, regardless of race, color, sex, religion, national origin, disability, political beliefs, sexual orientation, marital or family status and is an equal opportunity employer.Clemson University Cooperating with U.S. Department of Agriculture, South Carolina Counties, Extension Service, Clemson, South Carolina. Issued in Furtherance of Cooperative Extension Work in Agriculture and Home Economics, Acts of May 8 and June 30, 1914Public Service Activities
Wednesday, May 16, 2007
seed Technology
Lecture no. 16 , 18 and 19 Seed processing
The process of removal of dockage in a seed lot and preparation of seed for marketing is called seed processing. The price and quality of seed is inversely related to dockage, which should not exceed a maximum level permitted for different crops for seed certification.
Due to the operation of processing the level of heterogeneity of seed lot gets narrowed down.
The heterogeneity occurs in a seed lot due to following reasons:
Variability in soil for fertility, physical, chemical and biological properties
Variability in management practices (irrigation, application of nutrients etc.)
Variability in ability of the seedling for utilizing the inputs
Variability in pest and disease infestation
Position of pod or fruit in a plant or the position of seed in a pod.
Principle of seed processing: the processing operation carried out based on the principal physical differences found in a seed lot.
Physical differences found in seed are
Physical difference Suitable machineries
1. Seed size – varied from small to bold Air screen cleaner cum grader
2. Density- ill filled, im matured to well matured Specific gravity separator
light weight to dense seed
3. Shape – round to oval and different shapes Spiral separator
4. Surface texture – smooth to wrinkled and rough Roll mill / dodder mill
5. Colour of the seed – light color to dark colors Electronic color shorter
6. Conductivity of seed – low to high Electronic separator
Requirement in seed processing
- There should be complete separation
- There should be minimum seed loss
- Upgrading should be possible for any particular quality
- There should be have more efficiency
- It should have only minimum requirement
Types of materials removed during seed processing
- Intert materials
- Common weed seeds
- Noxious weed seeds
- Deteriorated seeds
- Damaged seeds
- Other crop seeds
- Other variety seeds
- Off-size seeds
Sequence of operation in seed processing
- Sequence of operations are based on characteristics of seed such as shape, size, weight, length, surface structure, colour and moisture content. Because each crop seed possesses individually seed structure. Therefore, sequence of operation will be applied proper equipments. However, It is also involved stages following as
- Drying
- Receiving
- Pre-cleaning
- Conditioning
- Cleaning
- Separating or Upgrading
- Treating (Drying)
- Weighting
- Bagging
Storage or Shipping
Processing involved three steps :
Step 1. Pre- conditioning and pre cleaning
Pre conditioning : Isolation of seed from plant parts with which it was harvested . eg. Shelling
Pre cleaning : Removal of external materials like trash, stones, clods which are either in larger size or lighter in weight. No pre cleaning is required for hand harvested and winnowed seeds
The machineries involved in this operation are :
Scalper : Removes the larger inert matter from the seeds . If it contains a single sieve it is called as scalpers , two sieves – rough cleaners. The unit consists of a vibrating or rotating screen or sieve having perforation large enough to allow the rough seed pass through readily.
Debearders : The machine has horizontal beater with arms rotating inside a steel drum. When the seeds pass through it do the action of rubing the seeds and clip the seeds of oats, debeard barley, thresh white- cap in wheat, remove awns and beards, de hull some grass seeds and polish the seed.
Huller – scarifier : Have two rubber faced rough surfaces to rub the seeds. Dehulling ( removal of outer coat or husk) and scarifier ( scratching the seed coat) can be done simultaneously or separately.
Seed – rotating disc- centrifugal force – thrown – huller- - suction chamber- removes lighter seeds .
Maize sheller : 1. high capacity power operated shellers - bulk
2. Hand shellers – breeder or nucleus seed.
Step –2. Basic cleaning
The second stage of cleaning is carried out with air blasts and vibrating screens and is applicable to all kinds of seeds. It is essentially the same as scalping but more refined. It is performed mostly by one machine known as air-screen cleaner.
Air-Screen cleaner cum grader
The air-screen machine (Fig. 2) is the basic cleaner in most seed processing plants. Almost all seed must be cleaned by air-screen cleaner before specific specifications can be attempted. Machine size varies from small, two-screen farm models to large industrial cleaners with 7-8 screens. Two-screen models are used on farms, in breeder and foundation seed programs and by experiment stations for processing small quantities of seed. In most machines separations are made on the basis of differences in only one physical characteristic. The air-screen machine, however, effects separations on the basis of differences in size and weight of seeds. This enables the air-screen machine to use three cleaning elements: aspiration, in which light material is removed from the seed mass; scalping, in which good seed are dropped through screen openings; but larger material is carried over the screen into a separate spout; and grading, in which good crop seed ride over screen openings, while smaller particles drop through.
)
Cleaning and Grading
To obtain quality seed, it is necessary to clean the seed obtained from the farm to get rid of inert materials, weed seeds, other crop seeds, other variety seeds, damaged and deteriorated seed. Different kinds of seeds can be separated when they differ in one or more physical characteristics. Physical characteristics normally used to separate seeds are size, shape, length, weight, colour, surface texture, affinity to liquids, electrical conductivity, etc. The problem lies in identifying the most important property and use the machine that separates seed using the identified property. Some of the identified properties and machines operating by following the properties are listed below:
Name of the Separator
Property followed
Uses
Vibratory separator
Shape and surface texture
Removal of weed seeds
Spiral separator
Shape or the degree of its ability to roll
Separation of damaged/flat and wrinkled seeds from smooth seeds. Separation of mustard, rape, soybean and peas from wheat, flax, oats, etc., and round seeds from flat seeds.
Disk / Indented cylinder separator
Length
Dissimilar material like wheat, rye, mustard, barley from oats
Electrostatic separator
Electrical property
Johnson grass from sesame seed
Electronic colour sorters
Colour / brightness
Separation of off coloured seeds
Inclined draper
Shape and surface texture
Separation of smooth or round seeds from rough flat or elongated seeds
Magnetic separator
Surface texture and stickiness
Removal of contaminating weed seed from clovers, alfalfa seeds and iron metals
Roll mill
Shape and surface texture
Separation of smooth clover seed
Gravity separator or Destoner
Density or specific gravity
Removal of badly damaged, deteriorated, insect damaged crop seed and stones from good seeds.
Fig. 3. Specific gravity separator Fig. 4. Indented cylinder separator
Upgrading
Seed lots require further cleaning treatment to remove adulterants that are similar to pure seed in size and shape, to be separated by air screen cleaner. Removal of seeds larger or smaller than required size (sizing) and removal of cracked, damaged or otherwise defective seeds (grading) is accomplished in this final stage of processing.
Specific gravity separation
This method makes use of a combination of weight and surface characteristics of the seed to be separated. The principle of floatation is employed here. A mixture of seeds is fed onto the lower end of a sloping perforated table. Air is forced up through the porous deck surface and the bed of seeds by a fan, which stratifies the seeds in layers according to density with the lightest seeds and particles of inert matter at the top and the heaviest at the bottom. An oscillating movement of the table causes the seeds to move at different rates across the deck. The lightest seeds float down under gravity and are discharged at the lower end, while the heaviest ones are kicked up the slope by contact with the oscillating deck and are discharged at the upper end. This machine separates seeds of the same density but of different size and seeds of the same size but of different densities.
Indented cylinder
This helps to separate seeds according to the length. The equipment consists of a slightly inclined horizontal rotating cylinder and a movable separating trough. The inside surface has small closely spaced hemispherical indentations. Small seeds are pressed into the indents by centrifugal force and can be removed. The larger seeds flows in the centre of the cylinder and is discharged by gravity.
Magnetic separator
The magnetic separator separates seed according to its surface texture or related seed characteristics. First, seed is treated with iron filings, which adhere to rough surface alone. The treated seed lot is passed over a revolving magnetic drum and separated from smooth, uncoated seed. It may help to add varied amounts of water while mixing seed and powder, depending on the seed type. At any rate, the effectiveness of magnetic separation depends on the components of the seed lot and on the powder and water used in the treating operation. The greater the difference between surface textures of the seed lot’s components, more effective will be the separation.
Colour separator
The colour separator is used to separate discoloured seed, greatly of lower quality. Separation based on colour is necessary because the density and dimensions of discoloured seed are the same as those of sound seed, so other machines are not effective for separation. Electronic colour separation uses photocells to compare the seed colour with “background” which are selected to reflect the same light as the good seed. Seed that differs in colour is detected by the photo cells, which generate an electric impulse. The impulse activates an air jet to blow away the discoloured seed.
Friction cleaning
The air-screen combinations cannot remove debris that has a size and density similar to the seeds. However, if the debris has a different surface texture, it may be possible to remove by friction cleaning. Any object rolling or sliding over a sloping surface encounters a certain friction depending on the texture of itself and that of the sloping surface. Separation is made on a velvet cloth or rubber belt with variable inclination, which ensures that the slope necessary for the run off of the seed is different from the slope necessary for run -off of the debris. The belt continuously moves upwards and removes the debris while the seeds roll down the slope.
Spiral separator
The separator, which classifies seed according to its shape and rolling ability, consists of sheet metal strips fitted around a central axis in the form of a spiral. The unit resembles an open screw conveyor standing in a vertical position. The seed is introduced at the top of the inner spiral. Round seeds roll faster down the incline than flat or irregularly shaped seeds, which tend to slide or tumble. The orbit of round seed increases with speed on its flight around the axis, until it rolls over the edge of the inner flight into the outer flight where it is collected separately. The slower moving seed does not build up enough speed to escape form the inner flight. Most spirals have multiple inner flights arranged one above the other to increase the capacity.
Liquid flotation
Cleaning by flotation relies on the principle that the density of the seed of a given species is specific both for filled and ill filled seed. In this method, liquids with a density or specific gravity between that of the full and empty seed are used. The specific gravity of the liquids used is such that the full seed sinks and the empty seed and light debris float.
lecture no . 20 and 21 Seed Treatment
Seed-borne and early season diseases and insects pose devastating consequences to crop production if not managed. Seed Treatments playing a significant role in improving the establishment of healthy crops leading to better yields. Seed Treatments are the use and application of biological, physical and chemical agents and techniques used with seed that provide seed and plant protection and improve the establishment of healthy crops.
Nothing will work upon a poor quality seed, no matter how lavishly other inputs are spent on the crop established from such seeds. Assured germinability and vigour are important parameters to be looked upon on the seeds. Seed treatment insured both. A successful treatment should bring about
· qualitative improvement in the seed,
· improve the field performance
· and storability,
· enable mechanised sowing and
· to transform seeds as a carrier of basic inputs such as pesticides, herbicides, nutrients etc., which redefines agriculture as a profit oriented art, business or science.
History of seed treatment
Some of the first recorded uses of Seed Treatment are from the Egyptian and Roman periods and involved a technique of using sap from onion ( Allium spp.). In the middle ages, Seed Treatments were made with liquid manure and chlorine salts. Salt water treatments have been used since the mid-1600s and the first copper products were introduced in the mid-1700s. The “still used today” technology of hot water treatment is documented from as early as 1765 in Wittenberg, Germany. Seed was placed in 45oC water for 2 hours, this provided control of certain fungal pathogens on the outer surface of the seed.
A Time of Transition to Modern Seed Treatments
The seed industry is continuously in a time of transition and improvement. Key milestones in the history of Modern Seed Treatment are the introduction and ban of arsenic (used from 1740 until 1808), the introduction and ban of Mercury (used from 1915 until 1982). The launch of the first systemic compound in 1960; until then, Seed Treatments had been only seed sterilants and did not move into the plant. During the 1970’s the first systemic Seed Treatment fungicides for air-borne pathogens were introduced. In the 1990’s, new modern classes of fungicide and insecticide chemistry were launched.
Today’s Modern Seed Treatment
The objectives of modern Seed Treatment products are the superior control of certain insects and diseases while improving crop safety leading to good establishment of healthy and vigorous plants. Modern Seed Treatment formulations must also contribute to improvements in farmers’ and workers’ safety and stewardship of the environment.
Based on purpose, the types of seed treatments are
i) presowing
ii) prestorage and
iii) midstorage treatments.
Presowing Treatment
For any crop the time from sowing to seedling establishment is a crucial period in which the seed is exposed to a wide range of environmental stress that can adversely affect its performance. The presowing treatments helps the seed to cope with such problems .The presowing treatments are classified under the following :
Pre sowing Treatment
i..Dormancy breaking treatments
1. Soaking in water
2. Mechanical scarification
3. Acid scarification
4. Bio scarification
5. Scorching
6. Warm stratification
7. Cold stratification
8. Electrical seed treatment
ii. Germination augmenting treatments
1. Seed fortification/infusion
2. Dry permeation
3. Seed hardening
4. Seed priming
5. Humidification
6. Irradiation
7. Magnetic seed treatment
iii. Seed coating treatments
1. Seed pelleting
2. Seed coating / film coating
3. Seed colouring
4. Fluid drilling or gel seeding
iv. Seed protection treatments
Biological seed treatment
Seed dressing
Dormancy breaking treatments
i) Soaking in water
It refers to soaking of seeds in cold or hot water for a period ranging from few hours to several days.It is intended to break physical or chemical dormancy.
In the case of cold water soaking, seeds are soaked in cold water for one to three days; but once in 12 h water should be changed to avoid fermentation. Sometimes seeds can be soaked in running water for a day to leach out the inhibitors eg., coumarin in coriander; hydrocyanic acid in sunflower.
In the case hot water treatments, seeds should be soaked in boiled water, just removed from the heat source for one to 80 minutes.Physical dormancy caused by hard seed coat is overcome by softening of the seed coat. Chemical dormancy caused by presence of inhibitors is overcome by leaching of the inhibitors.
ii) Mechanical scarification
This denotes rubbing or aberration of seeds against hard surface.It is done to partially damage the hard seed coat.
Mode of action
During the scarification the seed coat is aberrated thereby the hard seed coat is made permeable to water.
iii) Acid scarification
Treating the seeds in sulphuric acid for a pre- standardized duration. It is done in order to overcome physical dormancy caused by hard seed coat
It is done by soaking the seeds in concentrated or diluted sulphuric acid for a pre-standardized duration with often stirring and washing the seeds for 5-10 minutes to remove all traces of acid. Shade dry the seeds.
iv) Bioscarification
It is subjecting the seeds to pretreatment by making use of animals and microorganisms as an important factor in the breakdown of seed coat impermeability. It is done to break down seed coat impermeability.
a) Animals
Pods of Acacia nilotica are fed to penned sheep or goats and the seeds are collected from the droppings. The combination of moisture, warmth and chemical action of the digestive juices softens the hard seed coat and it become permeable.
b) Insects
Termites are an important agent for breaking down seed coat dormancy in many parts of tropics as it feed and remove the exocarp eg. Terminalias.
v.)Stratification
It is a method of exposing imbibed seeds to higher temperatures for a period of
time. It is done to overcome mechanical and morphological dormancy. Soak the seeds in several times of their volume of cold water at approximately 3-5°C for 48 h. Drain off the water and mix the seeds with two to four times their volume of a moistened, water retained medium such as sand, sand peat mixture or vermiculite. Store at a warm temperature. A constant temperature of 20-25°C or alternating temperature of 20°C and 30°C is suitable for many species. Open the containers weekly, mix seeds and if surfaces show signs of drying, remoist with water spray. Periods of treatment vary form 2 weeks to 16 weeks depending on species.
vi) Cold stratification
It is a method of exposing imbibied seeds to lower temperatures for a period of
time. It is done to overcome physiological dormancy.Seeds should be soaked in several times their volume of water before prechilling, at 3-5°C for 48 h. After soaking, the water is drained off and moist seeds are stored at 3-5°C for the period appropriate to each species. Storage may be without any medium i.e. seeds as such or the seeds may be mixed with 2-4 times its volume of a medium such as moist sand, peat or a mixture of these two. Containers shall be opened and mixed if surfaces dry off. eg., Abeis spp, Eucalyptus delegatensis etc.
Germination augmenting treatments
i) Seed fortification/infusion
It is process of enriching the seeds with bioactive chemicals for improving the germination and seedling vigour
To the known volume of seeds one third volume of the nutrient solution is added and allowed to imbibe for short duration. The imbibed seeds should be dried under shade.
ii) Dry permeation
It is soaking of seeds in organic solvents like acetone, petroleum ether and dichloromethane containing desired hormonal and non hormonal chemicals for 2-3 h followed by evaporation of the solvent in air. It is an approach to improve the germinability and vigour of the seed by infusion of bioactive chemicals into the seed without altering seed moisture content.
iii) Seed hardening
It is the process of hydrating the seed to initiate the pre-germinative metabolism followed by dehydration which fixes the biochemical events. It is done in order to impart resistance against stress conditions viz., drought and cold, to the emerging seedlings
Seeds or grains are allowed to take up a certain amount of water, and then they are kept moist at 100 - 250C for several hours before drying in a steam of air. The best results can gain in two - three cycles of wetting and drying, although for some one cycle is sufficient. Different amounts of water are recommended for different species and cultivars of seed or grain.
iv) Seed priming
It is the process of controlled hydration of seeds to a level that permits pre-germinative metabolic activity to proceed, but that prevents actual emergence of the radicle.
Seeds are soaked in variety of solutes, including solutions of various inorganic salts, sugars and polyethylene glycol (PEG) a chemically inert, high molecular weight compound does not penetrate the cell walls. The temperature suggested during priming is between 100 - 150C. The duration of priming varies with the crop.
Heydecker et al (1973) used different terms depending upon the methods adopted for priming.
(i). Osmopriming - Soaking the seeds in osmotic solutions
(ii) Halopriming - Soaking the seeds in salt solutions
(iii) Biopriming - Coating the seeds with biological agents like bacteria
(iv) Solid matric priming - This consists of mixing seeds with an organic or inorganic carrier and water for a period of time. The moisture content of the matric is brought to a level just below what is required for radicle protrusion. Seed water potential is regulated by the matric potential of the seed and during priming the water is largely held by the carrier. Seeds can imbibe water from the carrier till the equilibrium is reached.
vi) Irradiation
Presowing irradiation of the seeds is a novel measure to increase the yield potential by improving germination and vigour. Air dried seeds are irradiated by using experimental gamma units. The unit consists of a definite configuration of irradiator such as a hollow cylinder or a linear or flat irradiator and maintaining an accurate time exposure for conducting the experiment.
In the process of the growth and development of plants raised from irradiated seeds, beginning from seedling emergence and ending with the ripening, there appears new, quite diverse changes manifested in the acceleration of the cell division rate, enhancement of growth and development, change of organogenesis, yield increase and its quality change, ie., there emerges a very complicated sequence of changes which has been termed as the effect of distant irradiation action.
vii) Magnetic seed treatment
It is a simple treatment which involves exposure of seeds to a magnetic field to improve germination and vigour for specified duration.
Magnetically treated seeds respire slowly but register higher respiration quotient values with increased enzyme activity viz., α -amylax and nitrate reductase
Seed coating treatment
i) Seed pelleting
It is the process of enclosing the seed inside a small quantity of inert material just large enough to produce a globular unit of standard size
Seeds are introduced into a coating drum or pan that resembles a cement mixer. An amalgam of pelleting materials (clays, limestone, calcium carbonate, talc, vermiculite) and cementing adhesives (gum arabic, gelatin, methylcellulose, polyvinyl alcohol, polyoxylethylene glycol-based waxes) are used to form the pellet and other compounds such as innoculants, fungicides, etc. may be added to enhance seed performance. As drum rotates, the seeds are first sprayed with water followed by the addition of the pelleting materials with binder. The wet seed attracts and becomes coated with the dry pelleting material and the pellet gradually increases in size with each turn of coating drum . Longer rotation times with greater amounts of pelleting materials lead to greater pellet size and roundness. At the end of the pelleting process, a binder is added to harden the outer layer of the pellet.
The ingredients of the seed pellets exerts respective positive influence on seed performance eg., Diammonium phosphate stimulates prolific root growth.
.ii) Seed coating / film coating
It is a process of applying useful materials to form a continuous layer of this coating over seed without altering the shape or size. The advantage of film coating over other coating process is the absence of dusting off “Problem and improvement of seed flow in planting equipment.
The application of seed coating is very similar to the slurry seed treatment and similar equipment is used, where in the seeds are sprayed or dipped in the dissolved additives and immediately dried film coating involves application of additives dissolved in a dyed solution of a ‘stickly’ polymer and immediately dried.
The ingredients of the seed coating excerts respective positive influence of the on seed performance eg., Bavistin protects the seedling from wilt disease
iii) Seed colouring
Colouring of seeds using natural or artificial dyes. It is done to
· to prevent inadvertent use of treated seeds for food or feed purposes
· to identify the seeds eg., A line, Bline, Rline etc.,
· to project their seed in the market eg. Private companies
The seeds are sprayed or dipped in the dissolved dyes
iv) Fluid drilling or gel seeding
It is mixing of pre germinated seed in a viscous gel, which is sown with an appropriate droll to maintain the seed moisture of the pre geminated seeds and to prevent injury to emerged radical.
Seeds are germinated in aerated water until radicle emergence and then they are mixed in a viscous gel eg., alginate gel. The viscous gel provides a cushion to the emerged radicle thus preventing any mechanical damage during drilling. The gel also gives a protective covering to the seed against any moisture loss.
v) Seed protection treatments
They are the treatments that use beneficial microorganisms to offer the potential for sustained plant growth.It can serve two purposes viz., seed protection and nutrient supplementation.Seeds are mixed with adhering such as rice gruel, and coating with the specific biological strains in appropriate proportions followed by surface drying.
Seed protection : Fungi such as Trichoderma, Pythium and Chaetomium controls damping off and other diseases. The bacterium clavibacter xylli cocuteracts European comporer by producing an insecticidal protein.
Nutrient supplementation : the bacteria such as Rhizobium and Azespirillum enhances root nodulation and increases nitrogen fixation
success is depends on
· the efficacy of biocontrol,
· the number of propogules added to the seed,
· the method of application and
· the control of other microbes in the application process.
vi) Seed dressing
It refers to the application of pesticides( fungicides, insecticides or a combination of both) to seeds before sowing in order to protect the seeds and young seedlings from soil borne pathogens..
Seeds are thoroughly mixed with required quantities of chemicals eg., Thiram and captan @ 2 g/kg of seeds or botanicals eg., leaf powder of Azadirachta indica and Vitex negundo
Pre storage treatments
The treatments given to the seeds prior to or during storage to protect the seed from deteriorative changes and from pest and diseases are called pre storage treatments. The types of pre – storage seed treatments are
1. Halogenation
2. Antioxidant treatment
3. Seed sanitation
4. Seed fumigation
i) Halogenation
a) Dry dressing
It is application of halogens like chlorine, bromine and iodine to seeds before storage as dry dusting to stabilize the lipoprotein biomembrane.
Procedure : Calcium carbonate, fresh chalk, talc charcoal or activated clay are first exposed to vapours of halogens and alcohols @ 2-5 g /Kg seed. An alternative method is to add the chemicals directly to the carrier ( 50 – 500 mg of chemical added to 2-5 g carrier for treating 1 Kg seed) in a closed container. Calcium carbonate has proved to be a good carrier. After equilibrating the carrier- chemical mix the seed is thoroughly dressed with the same and kept for 24-72 h in the closed container and thereafter stored in the usual way .Bleaching powder ( calcium oxy chloride ) may be directly mixed with the seed at the rate of 1-4 g / Kg seed.
b) Vapour treatment
Exposure of seeds to halogen vapour in a closed container for 16-72 h, to very low concentrations of halogens The concentration of chemicals and the time of exposure would depend on the material concerned.
ii) Antioxidant treatment
Application of antioxidants such as vitamin A,C,E, butylated hydroxytoluene (BHT) to seeds before storage as wet or dry treatments which delays the physiological ageing.The seeds are applied with antioxidants through soaking in respective solutions at particular concentration
Antioxidants such as vitamin A,C and E provides hydrogen atom for quenching the lipid radical thereby putting an end to free radical propagation and subsequent damage to cell membrane and ultra cellular structures.
.
ii) Seed sanitation
The seed sanitation treatments refers to the application of pesticides (fungicides, insecticides or a combination of both) to seeds to disinfest and disinfect them from various seed borne and soil borne pathogenic organisms and storage insect pests to safe guard the seed and seedlings against the seed and soil borne pathogens..Seed borne pests and diseases may be carried within seeds or on seeds or they may accompany the seed as free living organisms or in debris.
The seeds are simply dipped or soaked in the chemical solutions and the fungicides applied as dust, slurry or liquid in recommended concentrations.
a) Seed disinfection
This refers to the eradication of fungal spores that have become established within the seed coat or in more deep-seated tissues. For effective control the fungicidal treatment must actually penetrate the seed in order to kill the fungus that is present.
b) Seed disinfestation
This refers to the destruction of surface borne organisms that have contaminated the seed surface but have not infected the seed surface.
iv) Seed Fumigation
It is a process of exposing the seeds to fumigants (gaseous form of chemical) to control seed borne fungi and insects which cause seed deterioration during storage.
The seeds should be brought to equilibrium moisture contents at 60 per cent RH, then they should be enclosed in air tight containers and fumigated at temperature of 27±1.5 oC for required durations. After fumigation seeds placed in cloth bags are aerated for 21 weeks under room condition. Subsequent second and third fumigations are repeated after 3 and 6 months after first fumigation. Examples of fumigants are ethylene oxide, aluminium phosphide, calcium cyanide, ethylene dichloride and carbon tetrachloride, ethylene dibromide, carbon disulphide or hydrogen phosphide.
The toxic effects on the fumigants bring about the control of fungi or insects. The fumigant can penetrate into the seeds to control the deep-seated pathogens.Before going for fumigation a thorough knowledge of seed moisture level and type of infestation, choice of fumigant, its doses and exposure time and necessity of number of fumigation is very essential.
Mid storage treatments
Seeds in storage accumulate damage to cell membranes during senescence .Mid storage seed treatments are capable of reducing the age induced damages and restoring the seed vigour to a certain extent besides, the seed viability and productivity of stored seeds are also improved.
i)Hydration – Dehydration
It is the process of soaking the low and medium vigour seeds in water with or without added chemicals usually for short durations to raise the seed moisture content to 25 – 30% and drying back the seeds to safe limits for dry storage.
Types of H-D treatments
The wet treatments include soaking-drying, dipping-drying, spraying-drying, stepwise hydration-drying, moisture equilibration-drying, moisture equilibration soaking-drying, moist and conditioning-drying, etc. The choice of the treatment depends upon the characteristics of seed and initial vigour status of the seeds.
Soaking – Drying (S-D)
Stored seed is soaked in water or solution of chemicals sufficient to cover it and kept at room temperature for 2-6 hour depending on the material with occasional stirring. The soaked seed is taken out and after surface drying in the shade for some time, dried back to the original moisture content Dilute solution of chemicals such as sodium or potassium phosphate (di and mono basic), sodium chloride, p-hydroxy benzoic acid, p-amino benzoic acid, oxalic acid, potassium lodide, etc can also be used at 10-4 to 10-3 M concentrations. Fungicidal and insecticidal formulations can also be incorporated in the soak water.
Dipping – Drying (D-D)
Seeds are dipped in water or solutions of the aforesaid chemicals for only 2-5 minutes and the wet seed is taken out immediately and kept covered for 2 – 6 hours depending on the material, for absorption of surface water followed by drying back in S-D. This treatment is effective in most high and high-medium vigour seeds of rice, wheat, jute, summer and winter vegetables
Spraying – Drying
Seeds are spread in a thin layer and then an amount of water (approximately 1/5 to ¼ of the seed weight) is sprayed on to it in two equal installments (turning over the seed layer after the first spray) and then kept covered by a polythene sheet for 2-4 hours before drying back. This treatment is similar to D-D in its efficacy and suitability.
Moisture equilibration – drying (ME – D)
Here, the seeds are placed in thin layers on trays kept on a raised platform in a closed moisture saturated chamber lined internally with moist blotters giving nearly 100% RH at room temperature. After 24-48 hours, depending on the material and ambient temperature, the seed is dried back in the usual way. For soaking injury prone seeds this treatment, which gives a slow and progressive rise in moisture content, is very effective. ME-D, however, difficult to practice on a large scale and is not advocated for low vigour non leguminous seeds because of possible aging effect of the treatment especially when given for prolonged periods.
Moist sand conditioning – drying (MSC-D)
This treatment is similar to the moisture equilibration treatment but easier to practice. For slow and progressive moisture uptake, the seed is thoroughly mixed with pre-moistened sand, using 3 times the amount of air dry sand than seed. Moisture content of sand is adjusted to 5-10 by adding the requisite amount of water or solution of chemicals to previously washed and dried fine grain building grade sand. The addition of water should be so adjusted as to get the required hydration effect without initiating the germination process. After mixing the dry seed with the premoistened sand, the mixture is kept at room temperature for 16 – 36 hours depending on the material and sand moisture content. The seed absorbs moisture from sand and after incubation the hydrated seed is separated from sand by sieving and dried back to the original weight.
Mode of Action The main purpose of hydration is to raise the seed moisture content to 25 –30% (wet weight basis) before drying back to safe limits for dry storage. The hydration - dehydration treatment may improve the vigour by controlling free radical reactions and consequent peroxidative damage to lipoprotein cell membranes.
The hydration – dehydration treatments
1. should be given only to stored seeds.
2. is effective in low and medium vigour non- leguminous seeds,
3. the moisture equilibration and moist sand conditioning treatments in which moisture is taken up by the seed in a slow and progressive manner, are recommended for relatively high- vigour seeds and seeds of pulses and leguminous vegetable crops
6. Direct soaking of leguminous seeds should be avoided.
7. would not make a seed germinable, which has already lost viability.
Lecture No. 22 and 23 Seed certification
It is a legally sanctioned system for quality control and seed multiplication and production. It involves field inspection, pre and post control tests and seed quality tests.
Purpose of seed certification
To maintain and make available to the farmers, through certification, high quality seeds and propagating materials of notified kind and varieties. The seeds are so grown as to ensure genetic identity and purity.
Eligibility for certification of crop varieties
Seed of only those varieties which are notified under section 5 of the Seeds Act, 1966 shall be eligible for certification.
Breeder seed is exempted from certification. Foundation and certified class seeds come under certification.
Seed Certification Procedures or Phases of Seed Certification
1. Receipt and scrutiny of application
2. Verification of seed source
3. Field inspection
4. Post harvest supervision of seed crops
5. Seed sampling and testing
6. Labelling, tagging, sealing and grant of certificate
I. RECEIPT AND SCRUTINY OF APPLICATION
i. Application for registration
Any person, who wants to produce certified seed shall register his name with the concerned Assistant Director of Seed Certification by remitting Rs.25/- per crop, per season. There are 3 seasons under certification viz.,
kharif (June - September),
rabi (October - January) and
summer (February - May).
The applicant shall submit two copies of the application to the ADSC 10 days before the commencement of the season or at least at the time of registration of sowing report. On receipt of the application, the Assistant Director of Seed Certification will verify the time limit, varietal eligibility and its source, the class mentioned, remittance of fee etc., The application, if accepted will be given an application no (e.g. Paddy / k/01-97-98 where paddy refers the crops to be registered, K the season, 01-the application Number and 99-2000 the financial year). The original application is retained and the duplicate is returned to the applicant.
b. Sowing report (Application for the registration of seed farm)
The seed producer who wants to produce certified seeds shall apply to the Assistant Director of Seed Certification in the prescribed sowing report form in quadruplicate with prescribed certification fees along with other documents such as tags to establish the seed source.
Separate sowing reports are required for
a. different crop varieties, different classes,
b. different stages
c. if the seed farm fields are separated by more than 50 meters.
d. if sowing or planting dates differ by more than 7 days and
e. if the seed farm area exceeds 25 acres.
The sowing report shall reach concerned Assistant Director of Agriculture Seed Certification within 35 days from the date of sowing or 15 days before flowering whichever is earlier. In the case of transplanted crops the sowing report shall be sent 15 days before flowering. The producer shall clearly indicate on the reverse of sowing report,
the exact location of the seed farm
crops grown on all four sides of the seed farm etc.,
to facilitate easy identification of the seed farm by the seed certification officer.
The Assistant Director, Seed Certification on receipt of the sowing report, scrutinises and registers the seed farm by giving a Seed Certification number for each sowing report. Then he will send
one copy of the sowing report to the Seed Certification officer,
one to the Deputy Director of Seed Certification
third to the producer and
he retains the fourth copy.
Verification of seed source
During his first inspection of seed farm the Seed Certification officer will verify whether the seed used to raise the seed crop is from an approved source and correct class of seed.
Field inspection
Objective
The objective of conducting field inspection is to verify the factors which can cause irreversible damage to the seed crop on genetic purity.
Inspection authority
The seed certification officer authorized by the registering authority shall attend to field inspections
Stages of Inspection
The number of field inspections and the stages of crop growth at vary from crop to crop and depends upon duration and nature of pollination of the seed crop.
If the crop is grown for hybrid seed production, the number of field inspections during the flowering stage should be more than one.
In hybrid seed production and variety seed production of cross pollinated crops the inspection during flowering should be made without any prior notice of the seed grower to judge the quality of operation undertaken by him to maintain the genetic purity of the crop. If prior notice is given to the seed grower, it may not be possible to detect the damage by the contaminants
But in the case of self-pollinated crop the seed grower may be informed about the date of inspection. Prior notice will lead to improvement of the quality of the seed through rogueing.
The key points to be observed at each stage of inspection
Stage of crop
Key points to be observed at inspection
I. Pre flowering stage
(Vegetative Stage)
II. Flowering Stages
(May be II and III inspections when 50% of plants begin to flower).
a. Verification of seed source
b. Confirmation of acreage given in the report.
c. Isolation distance
d. Planting ratio
e. Border rows
f. Guide the grower in identification of offtypes, pollen shedder, diseased plants, shedding tassels etc.,
a. Confirm the observation of prior inspection
b. Confirm whether grower had continued thorough rouging, after the previous inspection.
c. Verify the removal and occurrence of offtypes, pollen shedders, shedding tassels, objectionable weed plants and diseased plants
III. Inspection during post flowering and pre-harvesting stage.
IV. Inspection during harvest
(This is the last inspection conducted on a seed crop).
a. Confirm the correctness of observations, made in earlier inspections.
b. Guide the grower on rouging, based on pods, earhead, seed and chaff characters such as colour, shape and size.
c. Explain to the grower when and how to harvest the crop and process.
a. Verify that male parent rows have been harvested separately.
b. Ensure complete removal of offtypes, other crops, weeds and diseased plants etc.,
c. Seal properly by the certification agency of the threshed produce after initial cleaning and drying.
d. Instruct the seed growers for safe storage and transportation.
Minimum number of field inspections required for different crops for certification
CROP
minimum No.of inspections
STAGES OF CROP
Paddy and Wheat
2
Flowering to harvest
Sorghum
Hybrid
4
Ist before flowering
IInd and
IIIrd during flowering
IVth prior to harvest.
Varieties
3
Ist before flowering
IInd during flowering
IIIrd prior to harvest
Maize
Inbred lines Single crosses
Other hybrids
4
Ist before flowering
Rest during flowering
Varieties
2
Ist before flowering
IInd during flowering
Bajra
Hybrids
4
Ist before flowering
IInd and IIIrd during flowering
IVth prior to or during harvest.
Varieties
3
Ist before flowering
IInd during 50% flowering
IIIrd prior to harvest
PULSES
Green gram,redgram
Black gram , cowpea
2
Ist before flowering
IInd flowering and fruiting stage
Groundnut
2
Flowering to harvest
Sesame
3
Ist before flowering IInd during flowering
IIIrd from fruit maturity to harvest
Sunflower
2
Flowering to harvest
Rape and mustard
3
Ist before flowering
IInd during flowering to fruiting
IIIrd from maturity to harvest
Soybean
2
Flowering to harvest
Castor
2
Flowering to harvest
Cotton (Varieties)
(Hybrids)
2
4 Flowering to harvest
Ist before flowering
IInd and IIIrd during flowering
IVth during harvest
Brinjal
Tomato
Chilli
Bhendi
3
Ist before flowering
IInd during flowering to fruiting
IIIrd during maturity.
Carrot
3
Ist early (20-30 days after sowing)
IInd when lifted and replanted
IIIrd during flowering
Cabbage
3
Ist before marketable stage
IInd when the heads have formed
IIIrd during flowering
Cauliflower
4
Ist before marketable stage
IInd during curd formation IIIrd when most plants have formed curds
IVth during flowering
Onion (seed to seed)
3
Ist during early vegetative stage IInd during bulb formation
IIIrd during flowering
Field counts
The purpose of field inspection is to find out field standards of various factors in the seed farm. It is impossible to examine all the plants in the seed farm. Hence, to assess the field standards random counting is followed.
Points to be observed before counting
1. All plants falling in each count must be examined for each factor
2. In hybrid seed field the prescribed number of the field counts should be taken in each parent separately.
Sources of contamination or factors to be observed
The contaminants are
1. Physical contaminants - inseparable other crop plants, objectionable weed plants and diseased plants
2. Genetical contaminants -. Consists off-types, pollen shedders and shedding tassels.
a. Off type -Plant that differs in morphological characters from the rest of the
population of a crop variety.
Off type may belong to same species or different species of a given variety. Plants of a different variety are also included under off types.
b. Volunteer plant- plants from a previous crop
c. Pollen shedders –presence of 'B' line in 'A' line.
d. partials - Some times 'A' line produce fertile anthers are called partials. These
partials are also counted as pollen shedders.
No.of counts :
It is necessary to take minimum of 5 counts upto 5 acres and an additional count for every 5 acres or part of as given below.
Area of the field (in acres)
up to 5
5
6-10
6
11-15
7
16-20
8
21-25
9
Double count
In any inspection. if the first set of counts shows that the seed crop does not confirm to the prescribed standard for any factor, a second set of counts should be taken for the factor.
However, when the first set of counts shows a factor more than twice the maximum permitted, it is not necessary to take a second count.
On completion of double count assess the average for the two counts. It should not exceed the minimum permissible limit.
Number of plants for a count
S.No
Crop
Number of plants / heads per count
Remarks
1
Soybean, Jute, Lucerne, Mesta, Berseem
1000 plants
Closely planted crops
2
Beans, cluster beans, cowpea, green gram, black gram, peas, mustard, sesame, bengal gram, safflower, niger
500 plants
Medium spaced crops
3
Bhendi, brinjal, chilli, castor, cole crops, cotton, cucurbits, ground nut, miaze, potato, red gram, tomato and sunflower
100 plants
Wide spaced crops
4
Bajra, barely, oats, paddy, wheat, ragi, sorghum
1000 heads
Tillering crops
Shedding tassels
These plants which shed pollen in female parent rows. When 5 cm or more of the entire spike, which shed or shedding are counted.
Inseparable crop plants
These are plants or different crops which have seed similar to seed crop
Crop
Inseparable crop plants
Wheat
Barely, oats, gram and triticale
Barely
Oats, gram, wheat and triticale
Oats
Barely, gram, wheat and triticale
Triticale
wheat, barely, oats, gram and rye
f. Objectionable weed plants
These are weeds
1. Whose seeds are difficult to separate once mixed
2. Which are poisonous
3. Which have smothering effect on the main crop
4. Which are difficult to eradicate once established
S.No
Crop
Common name of the weed
Botanical name
1
2
3
4
5
6
Paddy
Wheat
Sunflower
Bhendi
Rape and mustard
Lucerne
Wild rice
Wild morning glory
Wild sunflower
Wild okra
Mexican prickly poppy
Dodder
Oryza sativa var fatua
Convolvulus arvensis
Helianthus spp
Abelmaschus spp
Argemone mexicana
Cuscuta spp
Designated diseases
The diseases which may reduce the yield and quality of seeds are termed as designated diseases.
S.No.
Crop
Name of the disease
Casual organism
1
2
3
4
5
6
7
8
9
10
Wheat
Sorghum
Pearl millet
Cowpea
Greengram
Gingelly Sunflower Loose smut
Brinjal
Chilli
Tomato
Grain smut
Head smut
Ergot
Grain smut
Downy mildew
Anthracnose
Halo blight
Leaf spot
Downy mildew
Phomopsis blight
Leaf blight
Anthracnose
Early blight
Leaf spot
Tobacco mosaic virus
Ustilago tritici
Sphacelotheca sorghi
Sphacelotheca reiliana
Claviceps microcephala
Tolyposporium pencillariae
Scelerospora graminicola
Colletotrichum lindemuthianum
Psedomonoas phasiolicola
Cercospora sesami
Plasmopara halsterdii
Phomopsis vexans
Alternaria solani
Colletotrichum capsici
Alternaria solani
Stemphylium solani
(TMV)
Land requirement
The field offered for certified seed production should not been grown in the previous season with the same crop. If it was grown, the variety should be the same. In that case, the field should be irrigated at least 3 weeks before sowing and ploughed just prior to sowing, in order to destroy germinating seeds.
Isolation
Separation of seed fields from
fields of other varieties of the same crop,
same variety fields not confirming to varietal purity requirements
other related species fields and
fields affected by diseases to prevent genetic and diseases contamination.
The minimum distance to be maintained between the seed crop and the source of contaminant is called isolation distance.
Inspection report
The seed certification officer after taking field counts and comparing them with the minimum field standards, the observations made on the seed farm field should be reported in the prescribed proforma to
1. Deputy Director of Agriculture (Seed Certification)
2. To the Seed Producer
3. Assistant Director of Agriculture (Seed Certification) and
Fourth copy retained with see certificate officer
Assessment of seed crop yield
It is necessary to avoid malpractice's at the final stage during harvest operation. The seed certification officer is expected to fix the approximate seed yield.
Liable For Rejection Report (L.F.R)
If the seed crop fails to meet with any one factor as per the standards, Liable for Rejection report is prepared and the signature of the producer is obtained and sent to Deputy Director of Agriculture Seed Certification within 24 hours.
Re-inspection
For the factors which can be removed without hampering the seed quality, the producer can apply for re-inspection to the concerned Deputy Director of Agriculture Seed Certification within 7 days from the date of first inspection order. For reinspection half of the inspection charge is collected.
Post harvest supervision of seed crop
The post harvest inspection of a seed crop covers the operations carried out at the threshing floor, transport of the raw seed produce to the processing plant, precleaning, drying, cleaning, grading, seed treatment, bagging and post processing storage of the seed lot.
Pre-requisites for processing
1. Processing report should accompany the seed lot
2. It should be correlated with the estimated yield
3. Seed should be processed only in approved processing unit.
4. ODV test for paddy should be done at the time of sealing and issue of processing report or before processing. If the result exceeds 1% of the produce may be rejected.
5. Field run seed should be brought to the processing unit within the 3 months from the date of final inspection. Processing and sampling should be done within 2 months in oil seed crops and 4 months for other crops from the date of receipt in the processing unit.
In cotton the kapas from the passed lot should be moved to the ginning factory within 5 days from the date of issue of processing report. The ginning should be done within 3 months from the date of final harvest inspection report. Ginned seeds should be moved to seed processing unit within in 5 days of ginning. Inspection and sampling should be done within 3 months after ginning.
Intake of raw produce and lot identification
The seed certification officer in-charge of the seed processing plant may, after verification of the above stated documents and total amount of seed accept the produce for processing. After verification he should be issue a receipt to the seed grower. Each seed lot has to be allocated a separate lot number for identification.
Seed sampling and testing
During packaging Seed Certification officer will draw samples according to ISTA Procedure and send the sample to Assistant Director of Agriculture (See Certification) concerned within a day of sampling. The ADASC will in turn send the sample to the Seed Testing Laboratory within 3 days of receipt of the sample to testing seed standards viz., physical purity, germination, moisture content and seed health as prescribed. The Seed Testing Officer will communicate the result to the ADASC concerned within 20 days. On receipt of the analytical report the ADASC will communicate the result to the producer and Seed Certification officer.
Labelling, tagging, sealing and grant of certificate
After receiving the seed analytical report the Seed Certification officer will get the tag from the ADASC and affixes labels (producer's label) and tags (blue for Certified Seed and White for Foundation Seeds) to the containers and seals them to prevent tampering and grants certificate fixing a validity period for 9 months. Tagging should be done within 60 days of testing.
Resampling and reprocessing
When a seed lot does not meet the prescribed seed standards in initial test, on request of the producer Seed Certification Officer may take resample.
If the difference in germination analysed and required is within 10, then straight away resampling can be done. If it is >10, reprocessing and resampling may be done.
The producer should request the Seed Certification Officer concerned in writing within 10 days from the receipt of the result. No charge is collected for resampling.
When a seed lot, fails even after free sampling reprocessing can be taken upon special permission from Deputy Director Seed Certification. For such reprocessing a fee of Rs.20/- Q and lab charges Rs.10/- Q is collected.
SEEDS ACT AND RULES
Introduction
The seed is an important agricultural input and it plays vital plays vital role in increasing production and productivity. There is a need to safeguard the farmers with the supply of genetically pure and quality seeds. Any new variety produced by the Scientist has to be multiplied to many times to meet the needs of the farmers. In order to ensure the availability of quality seeds, Government of India have enacted seeds act 1966 and seed rules, 1968. The seed (Control) order 1983 promulgated under essential commodities act, 1955 in order to ensure the production, marketing and equal distribution of the seeds.
Seeds Act 1966.
The object of Seed Act is for regulating the quality of certain notified kind / varieties of sees for sale and for matters connected therewith. The seed act passed by the Indian Parliament in 1966 was designed to create a 'Climate' in which the seeds man could operate effectively and to make good quality seed available to cultivators. Seeds rule under the act were notified in September 1968 and the act was implemented in its entirely in October 1969. This act extent to the whole of India and it has 25 sections.
Seed legislation could broadly be divided into two groups
1. Sanctioning legislation
Sanctioning legislation authorities formation of advisory bodies, Seed Certification Agencies, Seed Testing laboratories, Foundation and Certified Seed Programmes, Recognition of Seed Certification Agencies of Foreign countries appellate authorities.
2. Regulatory legislation
Regulatory Legislation controls the quality of seeds sold in the market including suitable agencies for regulating the seed quality.On quality control basis, the Seeds Act could conveniently be divided into the following:
I. Minimum limit and lablelling of the notified kind / varieties of seed
a. Power to notify the kind / variety
b. Labeling provisions
c. Seed testing
d. Seed analyst
e. Seed inspectors
f. Penalty
g. General provisions
II. Seed Certification
III. Restriction of Import and Export of Seeds
1. Minimum limits and labelling
Quality control as envisaged in the Act is to be achieved through pre and post marketing control, voluntary certification and compulsory labelling of the seeds of noticed notified kind / varieties.
(a) Power to notify the kind / varieties
New varieties evolved by the State Agricultural Universities and ICAR institutes are notified and release /notified respectively under section 5 of the seeds act in consultation with the central seed committee and its sub committees constitute under section 3 and 3(5) of the Seeds Act. As on date more than 2500 varieties and 130 varieties were notified and denotified under this section.
List of varieties notified and denotified from 1969 to 1965 are compiled and made available in the form book called catalogue of varieties notified and denotified under section 5 of the Seeds Act functions of the Central Seed Committee and its sub-committee are defined in Clauses 3 and 4 of part II of seed rule.
(b) Labelling provision
Minimum limits for germination, physical purity and genetic purity of varieties / hybrids for crops have been prescribed and notified for labelling seeds of notified kind / varieties under section 6(a) of the Seeds Act. Size of the label, colour of the label and content of the label were also notified under sub clause (b) of Section 6 of Seeds Act. Colour of the label is opoline green and size of the label is 10 cm x 15 cm or proportionate thereof. Responsibility for making labelling content of mark or label, manner of marking, false / misleading statement on label etc., are defined under clause 7,8,9,10,11 and 12 of part V of seeds rule.
Section 7 of the act regulates the sale of notified kind or varieties. Accordingly no person shall keep for sale, offer to sell, barter or otherwise supply any seed of any notified kind or variety, after the dates recorded on the container mark or label as the date unto which the seed may expected to retain the germination not less than prescribed undr clause (a) of section 6 of the Act.
Seed Testing
There is a provision to set up a central seed laboratory and state sees laboratory to discharge functions under section 4(1) and 4(2) of the Seed Act, In the year 1968 there were 23 state seed testing laboratories in the country. At present there are 86 Seed testing laboratories functioning in the country. During 1995-96 these laboratories tested about 5 lakh samples. Seed Testing laboratories have been assigned certain important functions under part III (5) of Seed Rule.
Seed Analyst
State Government could appoint the Seed Analysts through notification in the Official Gazette under Section 12 of the Seed Act defining his area and his jurisdiction. Seed Analyst should posses certain minimum qualification as prescribed under clause 20 part IX of Seed Rule. Seed Inspectors Classes of seed
The State Government, under section 13 of the Act may appoint such a person as it thinks fit, having prescribed qualification (Clause 22 part IX of Seed Rule) through notification, as a Seed Inspector and define the areas within which he shall exercise jurisdiction for enforcing the seed law. He will be treated as a public servant with in a meaning of section 21 of the I.P.C. (45 of 1860).
He has power to examine records, register document of the seed dealer. He will also exercise such other powers as may be necessary for carrying out the purposes of this Act or rule made thereunder. Duties of Seed inspectors are defined in clause 23 of part IX of Seed rule.He can issue stop sale order in case the seed in question contravenes the provision of relevant Act and rules for which he can use form No.III. When he seizes any record, register documents or any other material , he should inform a magistrate and take his order for which he can use form No.IV.
Penalty
If any person, contravenes any provision of the Act or Rule, or prevents a seed inspector from taking sample under this Act or prevents a Seed Inspector from exercising any other power conferred on him could be punished under section 19 of the act with a fine of five hundred rupees for the fist offence. In the event of such person having been previously convicted of an offence under this section with imprisonment for a term, which may extend to six months or with fine, which may extent to one thousand rupees of with both.
Seed certification
The object of the Seed Certification is to maintain and make available to the public through certification high quality propagating material of notified kind / varieties so grown and distributed as to ensure genetic identify and genetic purity. The certified standards inforce are Indian Minimum seed certification standards and seed certification procedures form together for the seed certification regulations.
Seed of only Seed if only those varieties which are notified under section under Section 5 of the seeds act shall be eligible for certification.
• Breeder seed
• Foundation seed
• Certified Seed
Breeder seed
• Breeder seed is a seed directly controlled by the breeder.
• Breeder seed should be genetically so pure as guarantee that in the subsequent generation.
• Breeder seed could not come under the purview of seed certification as it is not meant for public sale.
• Breeder seed should be packed and supplied with breeder's golden yellow tag. It is also the fact no standard for breeder seed have been prescribed.
Foundation seed
• Foundation class of seed and certified class of seed are to be certified by the Certification Agencies as per the Indian Minimum Seed Certification Standards.
• Section 8 of the Seeds Act provide state government or the Central Government consultation with State Government may be notification in official gazette, established certification agencies for the state to carry out the functions entrusted to certification agency by or under this Act (Part IV, clause 6, part VI clause 14 of Seeds Rule).
Certified seed
• Seed act section 9 provides any person desires of producing certified seed shall register his name with concerned seed certification agency duly remitting the prescribed fee in form No.1 for grant of certificate. Certificate could be granted in form No.11 after meeting the requirement of certification agency prescribed under Part VII clause 15,16 and 17 of Seed rule.
• It should have the minimum genetical purity of 99%
• Certified seed may be the progeny of certified seed , provided this reproduction does not exceed two generations beyond foundation seed and provided that if certification agency determines the genetic and physical purity, if not be significantly altered
• In case of highly self pollinated crops certification of one further generation may be permitted
• Certified seed produced from certified seed ,shall be eligible for further seed increase under certification, except in case of highly self pollinated crops, where certification of one further generation may be permitted
• Certification tags issued once for certified seed not eligible for further seed increase under certification
• For paddy and wheat, certified seed produced from certified seed is eligible for certification by NSC up to two generations from foundation seed
Seed (Control) order, 1983
Restriction of Export and Import of Seeds
There is a provision to restrict export and import of seeds of notified kinds or varieties. The section 17 define as under
" No person shall for the purpose of sowing or planting by any person (including himself) export or import or cause to be exported or imported any seed of any notified kind or variety unless. a) It conforms to the minimum limits of germination and purity specified for that seed under clause (a) of Section 6 and
b) Its container bears in the prescribed manner the mark or label with the correct particular thereof specified for that seed under clause (b) of section 6.
Background of the case
The ministry of civil supply through an order dated 24.4.1983 had declared the seed for sowing or planting of food crops, fruits, vegetables, cattle fodder and jute to be essential commodities in exercise of power conferred by Section 2(a) (viii) of Essential Commodities Act, 1955. It was followed by the issue of seed (control) order dated 30th December 1983 by the Ministry of Agriculture, Dept. of Agriculture and Cooperation in exercise of powers contained in section 3 of Essential Commodities Act, which deals with Central Governments power to control, and regulate production, supply and distribution of essential commodities.
The seed (control) order 1983 had been notified as per Gazette notification G.S.R (832(E) dated 30.,12.1983. The notification under reference holds good and remains operative. Joint Secretary (Seeds), Government of India, Ministry of Agriculture, Department of Agriculture and Cooperation has been appointed as Seed Controller for implementation of seed (control) order.
Gist of the seed (Control) order 1983.
Issue of licence to dealers
All persons carrying on the business of selling, exporting and importing seeds will be required to carry on the business in accordance with terms and conditions of licence granted to him for which dealer make an application in duplicate in Form 'A' together with a fee of Rs.50/- for licence to licensing authority unless the State Government by notification exempts such class of dealers in such areas and subject to such conditions as may be specified in the notification.
Based on such enquiry as it thinks fit for licensing authority may grant in form 'B' or refuse in provisions of the Order. The refusal to grant licence shall be accompanied by clear recording of reasons for such refusal.
Renewal of licence
A holder of licence shall be eligible for renewal upon and applicable being made in the prescribed form 'C' (in duplicate) together with a feed of rupees twenty before the expiry of licence or at the most within a month of date of expiry of license for which additional fee of rS.25/- is required to be paid.
Appointing of licensing authority
The state government may appoint such number of persons as it thinks necessary to be inspector and define the area of such Inspector jurisdiction through notification in the official gazette.
Time limit for analysis of samples by Seed testing lab
Time limit for analysis of samples by seed testing lab and suspension / cancellation of license may be done by Licensing authority after giving an opportunity of being heard to the holder of license, suspend or cancel the license on grounds of mis-representation of a material particular or contravention in provision of the order.
Suspension / Cancellation of licence
The Licensing authority may after giving an opportunity of being head to the holder of licence, suspend or cancel the licence on grounds of mis-representation of material particular or contravention in provision of the Order.
Appeal
The state government may specify authority for hearing the appeals against suspension / cancellation under this order and the decision of such authority shall be final.
Any person aggrieved by an order of refusal to grant or amend or renew the licence for sale, export / import of seed may within 60 days from the date of Order appeal to the designated authority in the manner prescribed in the Order. Miscellaneous Plant variety protection and the Indian agriculture
The licencing authority may on receipt of request in writing together with Rs.10/- from amend the licence of such dealer.
Every seed dealer are expected to maintain such books, accounts and records to this business in order and submit monthly return of his business for the preceding months in Form 'D' to the licencing authority by 5th day of every month.
New seed policy
The Government of India evolved a new seed policy and which is implemented from October 1, 1988.
The policy laid a special emphasis on
- Import of high quality of seeds
- A time bound programme to modernize plant quarantine facilities
- Effective implementation of procedures for quarantine /post entry quarantine and
- Incentives to encourage the domestive industry
- Import of quality seeds.
1. Bulk import of seeds of coarse cereals, pulses and oil seeds may replace (or) displace the local productions.
2. Transfer of technology may not be actual one, because due to bulk import of seeds or import of technology, instead we can import the germplasm of superior variety if any and could be developed locally to meet the demand (i.e.,) incorporate the advantages of exotic variety to the local types(or) even direct multiplication's after adaptive trials.
3. As we have superior varieties of international standard (e.g.) Maize, Sorghum, Bajra, or even in oil seeds like groundnut etc., the bulk import is not necessitated. Instead we need varieties suitable to agroclimatic zones besides higher yields.
4. Import of flower seeds could be encouraged in order to earn foreign exchange through export of flours and it can be imported under (OGL) open general license. But there is a fear of introduction of new pest and diseases as they are coming without post entry quarantine checkup.
Strengthening of quarantine
Since, from 1st October 1988 only bulk import of seeds under taken without any progress either in the strengthening of quarantine facilities.
Threat of pest and disease
Introduction of new pest and disease would pose a new problem due to bulk import due to lack of post entry quarantine. To avoid this threat the imported seeds should be subjected to testing and it should be done by one person from ICAR. Entry of exotic variety without proper field testing may change the disease pattern if that particular strain is becoming susceptible to existing pathogens.
(e.g.) Karnal burnt - which was not noticed in the previous years and because a major disease on wheat after the introduction of Kalyansona.
Genetic erosion
It is another danger, due to introduction of similar strains there is a danger of genetic uniformity and also eliminates local diversified strains which leads to problem of non availability of improved strains if there is any out break of disease.
Incentives to domestic seed industry
Indigenous seed production / seed industry will be affected because of the entry of multi nation diseases. Since the policy is allowing indiscriminate bulk imports through private sectors at the same time the import duty on seeds has been reduced to 15 cent. Import duty on advanced machines and equipment used in seed production or processing has also been reduced and interest on post shiftement credit has also been slashed down to help importers.Income tax rebate and deduction are available to the tax paying units on the revenue expenditure on in house research and development. Incentives area also being provided to seed with located in backward areas and growth centres.
Seed testing
SEED SAMPLING
Seed sampling is to draw a portion of seed lot that represent the entire seed lot.
Introduction
Seed lot ‑ It is an uniformly blended quantity of seed either in bag or ‑in bulk.
Seed Size
Maximum quantity per lot
Larger than wheat and paddy
20,000 kg
Smaller than wheat and paddy
10,000 kg
Maize
40,000 kg
Sampling intensity
a. For seed lots in bags (or container of similar capacity that are uniform in size)
I. up to 5 containers Sample each container
but never, < 5 Primary sample
6-30 “ Sample atleast one in every 3 containers but never > than 5 P. S.
31-400 “ Sample atleast one in every 5 containers but never < 10 P. S.
401 or more Sample atleast one in every 7 containers but never < 80.
II. When the seed is in small containers such as tins, cartons or packets a 100 kg
weight is taken as the basic unit and small containers are combined to form sampling
units not exceeding this weight e.g. 20 containers of 5 kg each. For sampling purpose
each unit is regarded as one container.
b. For seeds in bulk
Up to‑500kg - Atleast 5 Primary sample
501 ‑ 3000 Kg - 1 Primary sample for each 300 kg but not less than 5
Primary sample
3001‑20,000 Kg - 1 Primary sample for each 500 kg but not less than 10
Primary sample
20,001 and above - 1 Primary sample for each 700 kg but not less than 40
Primary sample
PRINCIPLES OF SAMPLING
Sample is obtained from seed lot by taking small portion at random from different places and combining them. From this sample smaller samples are obtained by one or more stages. In each and every stage thorough mixing and dividing is necessary.
Methods of sampling
a. Hand sampling
This is followed for sampling the non free flowing seeds or chaffy and fuzzy seeds such as cotton, tomato, grass seeds etc., In this method it is very difficult to take samples from the deeper layers or bag. To over come this, bags are emptied completely or partly and then seed samples are taken. While removing the samples from the containers, care should be taken to close the fingers tightly so that no seeds escape.
b. Sampling with triers
By using appropriate triers, samples can be taken from bags or from bulk.
1. Bin samplers
Used for drawing samples from the lots stored in the bins.
2. Nobbe trier
The name was given after Fredrick Nobbe‑ father of seed testing. This trier is made in different dimensions to suit various kinds of seeds. It has a pointed tube long enough to reach the centre of the bag with an oval slot near the pointed end. The length is very small. This is suitable for sampling seeds in bag not in bulk.
3. Sleeve type triers or stick triers
It is the most commonly used trier for sampling : There are two types viz.,
1. With compartments 2. Without compartments.
It consists of a hollow brass tube inside with a closely fitting outer sleeve or jacket which has a solid pointed end. Both the inner tube as well as the outer tube have been provided with openings or slots on their walls. When the inner tube is turned, the slots in the tube and the sleeve are in line. The inner tube may or may not have partitions.
This trier may be used horizontally or vertically. This is diagonally inserted at an angle of 300C in the closed position till it reaches the centre of the bag. Then the slots are opened by giving a half turn in clockwise direction and gently agitated with inward push and jerk, so that the seeds will fill each compartment through the openings from different layers of the bag, then it is again closed and with drawn and emptied in a plastic bucket. This trier is used for drawing seed samples from the seed lots packed in bags or in containers.
TYPES OF SAMPLES
1. Primary sample
Each probe or handful of sample taken either in bag or in bulk is called primary sample.
2.Composite sample
All the primary samples drawn are combined together in suitable container to form a composite sample
3. Submitted sample
When the composite sample is properly reduced to the required size that to be submitted to the seed testing lab, it is called submitted sample. Submitted sample of requisite weight or more is obtained by repeated halving or by abstracting and subsequently combining small random portions.
4. Working sample
It is the reduced sample required weight obtained from the submitted sample on which the quantity tests are conducted in seed testing lab.
Weight of submitted sample
The minimum weight for submitted samples for various tests are as follows
1.Moisture test
100 gm for those species that have to be ground and 50 gm for all other species. 2.For verification of species and cultivar
2. For verification of species and cultivars
Crop
Lab only (g)
Field plot
& Lab (g)
Peas, beans, maize, soybean and crop seeds of similar
1000
2000
Size
500
1000
Barley, oats, wheat and crop seeds of similar size
200
500
Beet root and seeds of similar size
100
250
All other genera
3. For other tests like uri and count of other species
Crop
Size of
seed lot
(kg)
Size of
submitted
sample
Size of working
purity
Sample
count of other
species
Paddy
25,000
400
40
400
Wheat
25,000
1000
120
1000
Maize
40,000
1000
900
1000
Sorghum
10,000
900
90
900
Bajra
10,000
150
15
150
Red gram
20,000
1000
300 .
1000
Green gram
20,000
1000
120
1000
Black gram
20,000
1000
150
1000
Bengal gram
20,000
1000
1000
1000
Cowpea
20,000
1000
400
1000
Soybean
20,000
1000
500
1000
Groundnut (pods)
20,000
1000
1000
1000
Groundnut (kernels)
20,000
1000
600
1000
Gingelly
10,000
70
7
70
Sunflower (variety)
20,000
1000
250
1000
Sunflower (hybrid)
20,000
1000
125
250
Cotton linted (variety)
20,000
1000
350
1000
Cotton de-Tinted
20,000
350
35
350
(variety)
20,000
350
35
350
Cotton linted (hybrid)
20,000
250
25
250
Cotton de-Tinted
10,000
150
15
150
(hybrid)
10,000
150
15
150
Brinjal
20,000
1000
140
1000
Chillies
10,000
70
7
70
Bhendi
10,000
7
7
7
Tomato (variety)
10,000
100
10
100
Tomato (hybrid)
10,000
100
10
100
Cabbage
10,000
100
10
100
Cauliflower
Knolkhol
The samples taken may packed in bags, sealed and marked for identification. For moisture testing the samples should be packed separately in moisture proof polythene bag and kept in the container along with the submitted samples.
Information to accompany the sample
Date Kind Variety
Class of seed Lot No.
Quantity of seed in lot (kg)
Tests) required (1) Purity (2) Germination (3) Moisture
Senders Name and Address
Types of sample used in Seed Testing Laboratory
Service sample - Sample received from the farmers
Certified sample - Sample received from certification agencies or officers
Official sample - Sample received from the seed inspectors.
Mixing and dividing of seeds
The main objective of mixing and dividing of seeds is to obtain the representative homogenous seed sample for analysis by reducing the submitted sample to the desired size of working sample.
Method of mixing and dividing
1. Mechanical dividing
2. Random cups method
3. Modified halving method
4. Spoon method
5. Hand halving method
1. Mechanical method
The reduction of sample size is carried out by the mechanical dividers suitable for all seeds except for chaffy and fuzzy seeds.
Objective of mechanical dividing
· To mix the seed sample and make homogenous as far as possible
· To reduce the seed sample to the required size without any bias
· The submitted sample can be thoroughly mixed by passing it through the divider to get 2 parts and passing the whole sample second time and 3rd time if necessary to make the seeds mixed and blended so as to get homogenous seed sample when the same seeds passed through it into approximately equal parts.
· The sample is reduced to desired size by passing the seeds through the dividers repeatedly with one half remain at each occasion.
TYPES OF MECHANICAL DIVIDERS
1. Boerner divider
It consists of a hopper, a cone and series of baffles directing the seeds into 2 spouts. The baffles are of equal size and equally spaced and every alternate one leading to one spout. They are arranged in circle and are directed inward. A valve at the base of the hopper retains the seeds in the hopper. When the valve is opened the seeds fall by gravity over the cone where it is equally distributed and approximately equal quantity of seeds will be collected in each spout. A disadvantage of this divider is that it is difficult to check for cleanliness.
2. Soil divider
It is a sample divider built on the same principles as the Boerner divider. Here the channels are arranged in a straight row. It consists of a hopper with attached channels, a frame work to hold the hopper, two receiving pans and a pouring pan. It is suitable for large seeds and chaffy seeds.
3. Centrifugal or Gamet Divider
The principle involved is the centrifugal force which is used for mixing and dividing the seeds. The seeds fall on a shallow rubber spinner which on rotation by an electric motor, throw out the seeds by centrifugal force. The circle or the area where the seeds fall is equally divided into two parts by a stationary baffle so that approximately equal quantities of seed will fall in each spout.
II. RANDOM CUP METHOD
This is the method is suitable for seeds requiring working sample upto 10 grams provided that they are not extremely chaffy and do not bounce or roll (e.g.) Brassica spp.
Six to eight small cups are placed at random on a tray. After a preliminary mixing the seed is poured uniformly over the tray. The seeds that fall into the cup is taken as the working sample.
III. MODIFIED HALVING METHOD
The apparatus consists of a tray into which is fitted a grid of equal sized cubical cups open at the top and every alternate are having no bottom. After preliminary mixing the seed is pouted evenly over the grid. When the grid is lifted approximately half the sample remains on the tray. The submitted sample is successively halved in this method until a working sample size is obtained.
IV. SPOON METHOD
This is suitable for samples of single small seeded species. A tray, spatula and a spoon with a straight edge are required. After preliminary mixing the seed is poured evenly over the tray. The tray should not be shacked there after. With the spoon in one hand, the spatula in the other and using both small portions of seed from not less than 5 random places on the tray should be removed. Sufficient portions of seed are taken to estimate a working sample of approximately but not less than the required size.
V. HAND HALVING METHOD
This method is restricted to the chaffy seeds. The seed is poured evenly on to a smooth clean surface and thoroughly mixed into a mound. The mound is then divided into 1/2 and each half is mound again and halved to 4 portions. Each of the 4 portions is halved again giving 8 portions. The halved portions are arranged in rows and alternate portions are combined and retained. The process is repeated until the sample of required weight is obtained.
SEED PURITY ANALYSIS
The purity test is the first test to be made. Seed samples can contain impurities such as weed seeds, seeds of other crop species, detached seed structures, leaf particles and other material. The object of purity analysis is to determine the composition of the sample being tested by weight. To do this, a purity test is conducted, in which the working sample is separated into the following component parts:
i) Pure seed refers to the species under consideration. In addition to mature, undamaged seed, it includes, undersized, shriveled, immature and germinated seeds, provided they can be definitely identified as the species under consideration, more over it includes pieces resulting from breakage that are more than one half their original size Pure seeds includes the following:
A. Intact seeds
B. Achenes and similar fruits like caryopsis, schizocarpand mericarp with or without pedicel, perianth and whether they contain true seed unless it is apparent and when difficult to identify.
C. Pieces of seeds, achenes, mericarp and caryopsis resulting from breakage that is more than half the original size (Half seed rule). However, seeds of Leguminosae, Cruciferae and Coniferae are considered as inert matter if their seed coat is removed.
D. Clusters of Beta or pieces of such clusters with or without seeds that are retained by 200 x 300 mm sieve.
E. Florets and caryopsis of Grammae.
* florests and one flowered spikelets with an obvious caryopsis containing endosperm provided also that the caryopsis of particular genera and species have attained minimum sizes.
* Free caryopsis
* All florets and caryopsis (except broken florets and caryopsis half or less than half the original size and in the case of Dactylis glomerata excluding one-fifth of the weight of multiple floret in which the sterile floret extends to or beyond the tip of the fertile floret) remaining in heavy protein after blowing at an uniform blowing speed.
With reference to specific species:
Allium sp., Capsicum sp., Cucumis sp., Lycopsersicon sp., : Seed with or without seed except pieces of seed more than 1/2 the original size with or without seed coat.
Arachis sp., Cicer sp., Glycine sp., Vigna sp. : Seed, provided a portion of testa is attached, pieces of seed more than 1/2 the original size with or without seed coat.
Daccus sp. : Schizocarp with or without pedicel unless it is obvious that no seed is present Mericarp with or without pedicel unless it is obvious that no seed is present. Pieces of mericarp more than 1/2 the original size unless it is apparent that no seed is present. Seed with pericarp partially or entirely removed. Pieces of seed larger than 1/2 the original size with the pericarp partially or entirely remove.
Gossypium sp.: Seed with or without lint, pieces of seed more than 1/2 the original size.
Helianthus sp. : Achene unless it is obvious that no seed is present. Pieces of achene larger than 1/2 the original size unless it is obvious no seed is present. Seed with the pericarp partially or entirely removed. Pieces of seed large than 1/2 the original size partially or entirely removed.
Oryza sp. : Spilelet with lemma, palea and sterile glumes enclosing a caryposis. Floret with lemma palea enclosing a cryopsis. Free caryopsis.
ii) Other seeds shall include seeds and seed like structures of any plant species other than that of pure seed. iii) Inert matter includes seed units and all other matters and structures not defined as pure seed or other seed. It includes, seeds and seed like structures eg., achenes , caryopsis , mericarp and seeds of leguminosae less than ½ the original size with no seed coat.
To perform purity analysis, the working sample is kept over the purity work board at the base end. A small quantity of sample is brought to the middle of the board and split into two basic components as pure seed and inert matter. The inert matter is further divided as pieces of seeds less than 1/2 the original size, stones, pieces of leaves, weed seeds, other crop seed etc. The pure seed is further divided into pure seed and other distinct variety (ODV) etc. The pure seed and inert matter are weighed upto three decimals and percentage worked out. The weed seed, OCS, ODV are counted and reported as number per kg.
Instruments
1. Seed blower
It is used to remove the light weighted inert matter from the seeds. Working sample is kept at the lower portion of the tube and the required uniform upward flow of air is regulated upto prescribed period of time. Lighter matter is separated from the sample by air flow and settle down in the partition provided in the tube of the blower. The tube is removed and inert matter is collected.
2. Diapanascope
The purity work board is provided with light source in the background which facilitates easy separation of different component. It also helps better distinguishing of red pericarp from white percarb and short bold grains long slender grains from medium types.
The percentage by weight of each of the component parts shall be calculated to one decimal place. Percentage must be based on the sum of the weight of the components not on the original weight of the working sample, but the sum of the weights of the components must be compared with the original weight as a check against loss of material or other error. The result shall be reported to one decimal place and the percentage of all components must total 100. Components of less than 0.05% shall be reported as Trace. If the purity is less than the standard retirement the certification department will reject the seed.
Seed Moisture Estimation
The moisture content of a sample is the loss in weight when it is dried in accordance with the rules. It is expressed as a percentage of the weight of the original sample. The submitted sample shall be accepted for moisture determination only if it is in intact, moisture - proof container from which as much air as possible has been excluded. The determination shall be started as soon as possible after receipt.
Procedures
Weighing shall be in grams to three decimal places. Seeds of larger size are ground before drying unless its high oil content makes it difficult. After grinding, the sample is passed through different sizes of sieves. Pre-drying before grinding is required for samples having moisture content more than 17%. After pre-drying, the sub-damples are reweighed in their containers to determine the loss in weight.
I. Low constant temperature oven method
The working sample must be evenly distributed over the surface of the container. Weigh the container and its cover before and after filling. Place the container rapidly, on top of its cover, in an oven maintained at a temperature of 103 ± 2°C and dry for 17 ± 1 hours. The drying period begins at the time the oven returns to the required temperature. At the end of the prescribed period, cover the container and place it in a desiccator to cool for 30-40 minutes. After cooling, weigh the container with its cover and contents. The relative humidity of the ambient air in the laboratory must be less than 70% at the time of final weighing. ISTA prescribes the low constant temperature oven method, for all tree species. Normally oilseeds are subjected to low constant temperature oven method while cereals and pulses are subjected to high constant temperature oven method.
II. High constant temperature oven method
The procedure is the same as above except that the oven is maintained at a temperature of 130-133°C, the sample is dried for a period of four hours for tree species and no special requirement pertains to the relative humidity of the ambient air in the laboratory during determination.
The moisture content as a percentage by weight shall be calculated to one decimal place by means of the following formula:
100
(M2-M3) x ----------
M2 - M1
Where
M1 - is the weight in grams of the container and its cover,
M2 - is the weight in grams of the container, its cover and its contents before drying and
M3 - is the weight in grams of the container, cover and contents after drying.
If the material is pre-dried, the moisture content is calculated form the results obtained in the first (pre-dried), the second stages of the procedure. If S1 is the moisture lost in the first stage, and S2 is the moisture lost in the second stage, each calculated as above and expressed as a percentage, then the original moisture content of the sample calculated as a percentage is
S1 x S2
S1 + S2 - -----------
100
Grinding requirements
Crop
Grinding
Mesh size
Paddy, wheat, maize, sorghum, cotton
Fine
50% ground material is passed through 0.5 mm mesh
10% ground material remain on 1.00 mm mesh
Pea, chickpea, soybean, lathyrus
Coarse
50% ground material is passed through 4 mm mesh
Pre-drying requirements
Crop
Moisture content
Temperature required for drying °C
Duration
Maize
>25%
>0
2 - 5 hrs
Rice
>13%
130
5 - 10 min
Soybean
>10%
130
5 - 10 min
III. Universal moisture meter
Moisture estimation is made quick by the advent of digital moisture meters. The principle involved is that electrical conductivity of moist material is directly proportionate to the amount of moisture content in it.
Universal moisture meter is a popular and most dependable instrument for moisture estimation. The following are its essential parts:
(i) Compression unit (ii) Moisture meter dial
(iii) Thermometer (iv) Compression knob
(v) Cups of different volumes
A representative sample of prescribed weight or volume (Table ) is obtained and placed in the sample cup. It is fixed in the lower house of compression unit.
Meter is calibrated by pressing the button "CAL" and "BELL" with the help of calibration knob. Sample is compressed as per requirement with the help of compression knob and scale. At required compression the meter dial (M) is read by pressing the knob "Read" and bell. Temperature (T) is observed by the thermometer fixed in between meter dial and compression chamber. The reading M and T are intercepted on the corelator dial (moisture meter dial) by turning the temperature dial. On adjustment of both the reading mark of arrow on the outer reading of temperature dial indicates the moisture percentage. For some crops factor is also considered for estimation of moisture content (Table ).
Determination of moisture content by universal moisture meter
Crop
Sample size
Compression
Factor
Weight (g)
Volume*
FIELD AND FODDER CROPS
Barley
50
B
0.600
Maize
60
B
0.560
Oat
30
B
0.400
Pearl millet
60
B
0.500
Rice
50
B
0.550
Sorghum
50
B
0.675
Wheat
30
A
0.275
Add 1%
Moong and urid
A
0.275
Add 1.5%
Chickpea
C
0.500
Subtrat 1%
Horsegram
A
0.275
Lentil
A
0.250
x 0.7 + 3.5%
Pigeonpea, fieldpea
C
0.450
Castor
C
0.500
Multiplied by 0.5
Groundnut
25
0.300
Multiplied by 0.6
Groundnut (kernel)
26
0.450
Multiplied by 0.56
Safflower
15
0.450
Multiplied by 0.66
Sesame
0.550
Subtract 0.5%
Soybean
60
C
0.575
Subtract 2.5%
Sunflower
30
B
0.500
Multiplied by 0.6
Rape seed and mustard
0.450
Multiplied by 0.6
Cotton (linted)
30
C
0.360
Subtract 5%
VEGETABLES
Kidneybean
50
B
0.400
Okra
C
0.425
Cabbage
A
0.260
Multiplied by 0.6
Cowpea
A
0.325
Multiplied by 0.8
Cucumber
B
0.525
Multiplied by 0.8
Lettuce
B
0.500
Multiplied by 0.9
Onion
A
0.250
Subtract 2.5%
Tomato
25
B
0.250
Multiplied by 0.8
Turnip
25
0.200
Multiplied 0.8
Watermelon
B
0.425
Subtract 3.5%
Coriander
C
0.325
Multiplied by 0.6
* A,B and C - Container size
The moisture content must be reported to the nearest 0.1% in the space provided on the Analysis Certificate. Seed lot with moisture content more than the minimum seed certification standards (Table ) are recommended for drying
Minimum seed certification standard for moisture percentage
Crop
Sample in vapour proof container
Sample not in vapour proof bag
FIELD AND FODDER CROPS
Castor, mustard, taramira
5
8
Groundnut, niger, sesame
5
9
Cotton
6
10
Rape seed
7
8
Linseed, horsegram, rajmash, safflower, sunflower, jute
7
9
Berseem, lucerne, Indian clover
7
10
Soybean
7
12
Moong, urid, chickpea, fieldpea, pigeonpea, lentil, lathyrus, kidneybean, ricebean
8
9
Buffel, Dharaf, Dinanath, guinea, marvel, setaria and stylo grass
8
10
Wheat, maize, sorghum, pearl millet, barley, triticale, oat, minor millets, teosinte, forage sorghum
8
12
Rice
8
13
VEGETABLES
Rat tail radish, radish, turnip
5
6
Cole crops
5
7
All cucurbits
6
7
TPS, brinjal, tomato, chilli, capsicum, onion, fenugreek, lettuce, amaranth, asparagus
6
8
Carrot, celery, parsley
7
8
French bean
7
9
Cowpea, Indian bean, clusterbean, spinach, sugarbeat
8
9
Okra
8
10
SEED GERMINATION TEST
Principles
Germination tests shall be conducted with a pure seed fraction. A minimum of 400 seeds are required in four replicates of 100 seeds each or 8 replicates of 50 seeds each or 16 replicates of 25 seeds each depending on the size of seed and size of containers of substrate. The test is conducted under favourable conditions of moisture, temperature, suitable substratum and light if necessary. No pretreatment to the seed is given except for those recommended by ISTA.
Materails required
A. Substratum
The substratum, serves as moisture reservoir and provides a surface or medium for which the seeds can germinate and the seedlings grow.The commonly used substrata are sand, paper and soil.
I. Sand
a. Size of sand particle
Sand particles should not be too large or too small. The sand particles should pass thorough 0.80 mm sieve and retained by 0.05 mm sieve.
b. Toxicity
Sand should not have any toxic material or any pathogen. If there is presence of any pathogen, found, then the sand should be sterilized in an autoclave.
c. Germination Tray
When we use the sand, germination trays are used to carry out the test. The normal size of the tray is 22.5 x 22.5 x 4 cm. They tray may either zinc or stainless steel.
B. Method of seed placement
1. Seeds in sand(s)
Seeds are planted in a uniform layer of moist sand and then covered to a depth of 1 cm to 2 cm with sand.
2. Top of sand (TS)
Seeds are pressed into the surface of the sand
C. Spacing
We must give equal spacing on all sides of facilitate normal growth of seedling and to avoid entangling of seed and spread of disease. Spacing should be 1‑5 times the width or diameter of the seed.
D. Water
The amount of water to be added to the sand will depend on size of the seed. For cereals, except maize, the sand can be moistened to 50% of its water holding capacity. For large seeded legumes and maize sand is moistened to 60% water holding capacity.
II. Paper
Most widely used paper substrates are filter paper, blotter or towel (kraft paper). It should be have capillary movement of water, at vertical direction (30 mm rise / min.). It should be free from toxic substances and free from fungi or bacteria. It should \ hold sufficient moisture during the period of test. The texture should be such that the roots of germinating seedlings will grow on and not into the paper.
A. Methods
a. Top of Paper (TP)
Seeds are placed on one or more layers of moist filter paper or blotter paper in petridishes. These petridishes are covered with lid and placed inside the germination cabinet. This is suitable of those seeds which require light.
a. Between paper (PP)
The seeds are placed between two layers of paper
b. Roll towel method
The seeds are placed between two layers of paper and rolled in towels. The rolled towels are placed in a water source and kept in germinator or germination room
c. Inclined plate method
Germination on glass plate with germination paper and kept at an angle of 45 0
III. SOIL
Should be non-caking, free from large particles. It must free from weed seeds, bacteria, fungi, nematode and other toxic substances. Soil is not recommended for reuse.
B. TEMPERATURE
Normally most of the seeds germinat between 20-300 C
C. LIGHT
Light required seeds provided with light eg. Lettuce
GERMINATION REQUIREMENTS FOR DIFFERENT CROPS
Crop
Substratum
Temp 0 C
First count
( Days)
Final count
(days)
Pre - treatment
PAddy
BP,TP,S
20-30
5
14
Pre heat (500 C) soak in water for 24 hours
MAize
BP,S
20-30
4
7
-
Bajra
TP,BP
20-30
3
7
0.2% KNO3 92-3 hrs) /prechill
Sorghum
TP,BP
20-30
4
10
-
Redgram
BP
20-30
4
6
-
Blackgram
BP
30
4
7
-
Greengram
BP
20-30
5
8
-
Bengalgram
BP
20-30
5
8
-
Cowpea
BP
20-30
5
8
--
Peas
BP
20
5
8
-
Castor
BP
20
7
14
-
Groundnut
BP
20-30
5
10
-
Sunflower
BP
20-30
4
10
-
Sesame
TP
20-30
3
6
-
Cotton
BP,S
20-30
4
12
Reithove shells
Brinjal
TP,BP
20-30
7
14
EthreI (25 ppm) 48 hrs.
Tomato
TP,BP
20-30
5
14
Chillies
TP,BP
20-30
7
14
(Hot water 85° C 1 min)
Bhendi
BP,S
20-30
4
21
Onion
TP,BP
15-20
6
21
KN03
Carrot
TP,BP
20-30
7
14
KN03
Radish
TP,BP
20-30
4
10
Prechill
Cabbage
prechill
Cauliflower
TP
20-30
5
10
Prechill, KN03
Ash gourd
S
30-35
5
14
light
Biter gourd
BP,S
20-30
4
14
Bottle gourd
BP,S '
20-30
4
14
-
GERMINATION APPARATUS
1. Germination Cabinet / Germination
This is called chamber where in temperature and relative humidity are controlled. We can maintain the required temperature
2. Room germinator
It works with same principle of germinator. This is a modified chamber of larger one and the worker can enter into it and evaluate the seedlings. Provisions are made to maintain the temperature and relative humidity. This is used widely in practice.
3. Counting Board
This is used for accurate counting and spacing of seeds. This consists of 2 plates. The basal one is stationary and top one is movable. Both top and basal plates are having uniform number of holes viz., 50/100, when the plates are in different position. After taking the sample, the top plate is pulled in such a way that the holes are in one line so that the fixed number of seeds fall on the substratum.
4. Vacuum Counter
Consists of a head, pipe and wall. There are plates of 50 or 100 holes which can be fitted to the head. When vacuum is created the plate absorbs seeds and once the vacuum is released the seeds fall on the substrate.
5. Impression Board
Made of plastic / wood with 50 or 100 holes/pins. Here the knobs are arranged in equal length and space. By giving impression on the sand it makes uniform depth and spacing for seed.
D. Seedling Evaluation
ISTA classified the seedlings into different categories based on the development of essential structures
CATEGORIES OF SEEDLINGS
1. Normal seedlings
2. Abnormal seedlings
3. Hard seeds
4. Fresh ungerminated seeds
5. Dead seeds
1.Normal seedlings
Seedlings which show the capacity for continued development into normal plant when grown in favorable conditions of soil, water and temperature.
Characters of normal seedling
1. A well developed root system with primary root except in certain species of graminae which normally producing seminal root or secondary root
2. A well developed shoot axis consists of elongated hypocotyls in seedlings of epigeal germination.
3. A well developed epicotyl s in seedlings of hypogeal germination.
4. One cotyledons in monocots and two in dicots
5. A well developed coleoptile in graminae containing a green leaf
6. A well developed plumule in dicots
7. Seedlings with following slight defects are also taken as normal seedlings. Primary root with limited damage but well developed seminal root system in leguminosae (Pisum), graminae (maize), cucurbitaceae (cucumis) and malvaceae(cotton)
8. Seedlings with limited damage or decay to essential structures but no damage to conducting tissue
9. Seedlings which are decayed by pathogen but it is clearly evident that the parent seed is not the source of infection.
II. Abnormal Seedlings
Seedlings which do not show the capacity for continued development into normal plant when grown in favorable conditions of soil, water and temperature
Types of abnormal seedling
A. Damaged seedlings
Seedlings with any one of the essential structures missing or badly damaged
so that the balanced growth is not expected. Seedlings with no cotyledons, with splits, cracks and lesions or essential structures and without primary root.
B. Deformed seedlings
Weak or unbalanced development of essential structures such as spirally twisted or stunted plumule or hypocotyls or epicoptyl, swollen shoot, stunted roots etc.
C. Decayed seedlings
Seedlings with any one of the essential structures showing diseased or decayed symptoms as a result of primary infection from the seed which prevents the development of the seedlings.
III.Hard seeds
Seeds which do not absorb moisture till the end of the test period and remain hard (e.g.) seeds of leguminosae and malvaceae
IV.Fresh ungerminated seeds
Seeds which are neither hard nor have germinated but remain firm and apparently viable at the end of the test period.
V. Dead seeds
Seeds at the end of the test period are neither hard nor fresh'or have produced any part of a seedling. Often dead seeds collapse and milky paste comes out when pressed at the end of the test.
Retesting
If the results of a test are considered unsatisfactory it shall not be reported and a second test shall be made by the same method or by alternative method under the following circumstances.
1. Replicates performance is out of tolerance
2. Results being inaccurate due to wrong evaluating of seedlings or counting or errors in test conditions.
3. Dormancy persistence or phytotoxicity or spread of fungi or bacteria. The average of the two tests shall be reported.
Use of tolerances
The result of a germination test can be relied upon only if the difference between the highest and the lowest replicates is within accepted tolerances.
To decide if two test results of the same sample are compatible again the tolerance table is used.
Reporting results
The results of the germination test is calculated as the average of 4 x 100 seed replicates.It is expressed as percentage by number of normal seedlings.The percentage is calculated to the nearest whole number. The percentage of abnormal seedlings, hard, fresh and dead seeds is calculated in the same way. These should be entered on the analysis of certificate under appropriate space.If the result is nil for any of these categories it shall be reported as '0'.
Seed standards for germination
S.No.
Crop
Class of seed
Foundation Seed
Certified seed
1
Paddy
80
80
2
Maize (inbreds)
80
-
Single cross
80
80
Double cross
-
90
Variety
90
90
3
Sorghum (variety)
75
75
Hybrids
75
75
4
Cumbu
75
75
5
Ragi
75
75
6
Black gram
75
75
7
Bengal gram
85
85
8
Green gram
75
75
9
Horse gram
80
80
10
Peas
75
75
11
Pigeon pea
75
75
12
Castor variety
70
` 70
13
Ground nut
70
70
14
Sesame
80
80
15
Soybean
70
70
16
Sunflower
70
70
17
Cotton
65
65
18
Jute
80
80
19
Gourds
60
60
20
Brinjal
70
70
21
Chillies
60
60
22
Bhendi
65
65
23
Tomato
70
70
24
Cabbage
70
70
25
Cauliflower
65
65
26
Carrot
60
60
27
Radish
70
70
28
Beet root
60
60
QUICK VIBILITY TEST
The relative long periods of time required for completion of germination tests delays the seed marketing. This necessitated the development of rapid methods for estimating the germination capacity of seeds. This test was developed by Lakon (1942) in Germany.
Principle
It is a biochemical test, in which living cells are made visible by reduction of an indicator dye. The indicator used is 2,3,5 triphenyl tetrazolium chloride. Within the seed tissues, it interferes with the reduction processes of living cells and accepts hydrogen from the hydrogenases. By hydrogenation of the 2,35 ‑ tri phenyl tetrazolium chloride; a red stable and non difficusable substance, triphenyl formazan is produced in living cells. The reaction is as follows.
N-N ‑C6H5 N‑NH ‑C6H5
C6 H5 –C +2e+2H+ C6H5 ‑ C+ ~ + H+ Cf
N=N+ C61‑15 N=N‑ CA
Cl'
2,3,5 triphenyl tetra zolium chloride Triphenyl formazon
This makes it possible to distinguish red coloured living parts of seeds from the colourless dead ones. Staining of seeds determines whether seeds are to be classified as viable. Completely stained seeds are viable partially and completely unstained seeds are non‑viable
Field of application
This test is not valid for previously germinated seeds
Method of Tetrazolium testing
A. Testing sample
A representative sample of 50(or) 100 seeds is usually sufficient. l lowever, 200 seeds, in replicates of 100 seeds is recommended.
B. Preparation of solutions
1% solution is used for seeds that are not bisected thro' the embryo, while 0.1% solution is used for seeds in which the embryo is bisected.
The pH of the solution should be between 6 and 8 for best staining. If the pH of the water is not in the natural range, the TZ salt should be dissolved in a phosphate buffer solution. The buffer solution is prepared as follows
Solution ‑1‑ Dissolve 9.078 g of KH2 P04 in 1000 ml of water
Solution ‑2‑ Dissolve 11.876 g of Na2HP04. 2H20 in 1000 ml water.
Take 400 ml of solution 1 and 600 ml of solution 2 and mix them together. In litre of buffer solution prepared as above, dissolve 10 gms of TZ salt. This gives 1% TZ solution of pH 7.0. This may be further diluted to give lower concentrations. The solution should be stored in brown bottle to prevent deterioration from light.
Methods of preparation for tetrazolium testing
The seeds are first prepared for staining then stained and evaluated for viability.
Method 1 : Bisect longitudinally
(e.g) maize, sorghum, small grains, large seeded grasses. Soak the seeds in water for 3 to 4 hours. Bisect the seeds by cutting longitudinally thus exposing the mains structures of the embryo. Use one 1/2 of each seed for testing.
Method 2 : Bisect laterally
(e.g.) Small seeded grasses
The seeds are cut laterally near the centre of the seed above the embryo. Place embryo end in TZ solution.
Method 3 : Pierce with needle
(e.g.) Small seeded grasses
Puncture the seeds by piercing thro' the seed into the endosperm near the embryo, but avoid injury to the embryo.
Method 4 : Remove seed coat (e.g) seeds with seed coats impermeable to tetrazolium.
Soak the seeds in water for 3‑4 hours and then the seed coats and place the seeds in the TZ solution. In some crops like cotton a thin membrane adhering .to the cotyledons is also removed in addition to the seed coat.
Method 5 : Conditioning only
(e.g) Large seeded legumes
Seeds of soybeans and other large seeded legumes may swell so rapidly and irregularly when placed directly in water or TZ solution that the seed coats burst. Hence, it is preferable to condition these seeds slowly in moist paper towels overnight before staining, so that they absorb moisture slowly without any damage to the seed.
but avoid injury to the embryo.
Method 4 : Remove seed coat
(e.g) Dicots with seed coats impermeable to tetrazolium.
Soak the seeds in water for 3‑4 hours and then the seed coats and place the seeds in the TZ solution. In some crops like cotton a thin membrane adhering .to the cotyledons is also removed in addition to the seed coat.
Method 5 : Conditioning only
(e.g) Large seeded legumes
Seeds of soybeans and other large seeded legumes may swell so rapidly and irregularly when placed directly in water or TZ solution that the seed coats burst. Hence, it is preferable to condition these seeds slowly in moist paper towels overnight before staining, so that they absorb moisture slowly without any damage to the seed.
Method 5 : Conditioning only
(e.g) Large seeded legumes
Seeds of soybeans and other large seeded legumes may swell so rapidly and irregularly when placed directly in water or TZ solution that the seed coats burst. Hence, it is preferable to condition these seeds slowly in moist paper towels overnight before staining, so that they absorb moisture slowly without any damage to the seed.
METHOD 6 : NO CONDITIONING OR PREPARATION
(eg.) Small seeded legumes
Seed coats of these seeds are permeable to TZ and embryos usually will stain without conditioning.
Staining
The prepared seeds should be placed in suitable container (small beakers, petridishes
etc.,) and covered with TZ solution. Place the containers in an incubator at dark warm conditions of 40°C.The staining time varies for different kinds of seeds, different kinds of seeds, different methods of preparation, and different temperatures (< 1 hr to 8 hrs).
When the sample has stained sufficiently the TZ solution should be discarded and the
seed sample covered with water immediately. Seed samples can also be kept for 3 days at 10°C for interpretation.
Evaluation of Samples : A normal TZ stain appears cherry red.
MONCOTS
Non‑Viable
1. All structures unstained
2. Shoot largely unstained
3. Scutellar node unstained
4. Major areas of coloeptile unstained
5. Central area of scutellum unstained
6. Insect, mechanical or other injuries causing essential structures non functional.
DICOT SEEDS
Non‑viable
1. Embryo completely unstained
2. More than extreme tip of radical unstained
3. More than 1/2 of cotyledon tissue unstained.
4. Deep ‑ seated necrosis at cotyledon and embryonic axis juncture or on radicle
5. Fractured radical.
Advantages of TZ test
I.Quick estimation of viability
2.When the seed is dormant, the TZ test is extremely useful
3. Seeds are not damaged (in dicot) in anlaysis therefore they could be germinated.
Disadvantages of TZ Test
1. It is difficult to distinguish between normal and abnormal seedlings.
2. It does not differentiate between dormant and non‑ dormant seeds.
3. Since the TZ test does not involve micro organisms harmful to germinating seedlings are not detected.
SEED STORAGE
What is seed storage - preservation of seed wioth initial quality until it is needed for planting.
Introduction
The ability of seed to tolerate moisture loss allows the seed to maintain the viability in dry state. Storage starts in the mother plant itself when it attains physiological maturity. After harvesting the seeds are either stored in ware houses or in transit or in retail shops. During the old age days , the farmers were used farm saved seeds, in little quantity, but introduction of high yielding varieties and hybrids and modernization of agriculture necessitated the development of storage techniques to preserve the seeds.
The practice of storing the seeds starts from the ancient days itself, following simple and cheap techniques eg. Placing the seeds ins alt, red earth treatment to red gram etc. But the same practices are not hold good for the present day agriculture, because
- large quantity to be stored
- exchange of varieties and species
- exchange of genes
The type of material to be stored decides the techniques to be followed for safe storage. Now a days storage technique changed from ordinary go-down storage to cryogenic tank storage and even gene storage.
Objective of seed storage :
To maintain initial seed quality viz., germination, physical purity, vigour etc., all along the storage period by providing suitable or even better conditions.
Factors influencing seed storage
Biotic
A biotic
Biotic factors :
a. Factors related to seed
- Genetic make up of seed
- Initial seed quality
- Provenance
- Seed Moisture content
b. Other biotics
- Insects
- Fungi
- Rodents
- Mishandling during sampling, testing
2. Abiotic factors
- Temperature
- Relative humidity
- Seed store sanitation
- Gaseous atmosphere
- Packaging material
Seed factors :
1.Genetic factors
The storage is influenced by the genetic make up of the seed. Some kinds are naturally short lived (e.g) onion, soybeans, ground nut etc., Based on the genetic make up seeds are classified into
Micro biotic – short lived
Meso biotic- medium lived
Macro biotic – long lived
Initial seed quality
Barton (1941) found that the seeds of high initial viability are much more resistant to unfavourable storage environmental conditions than low viable seed. Once seed start to deteriorate it proceeds rapidly. The seed which injured mechanically suffered a lot and loses its viability and vigour very quickly. Generally small seeds escape injury whereas large seeds are more likely to be extensively damaged (e.g) bean, lima-bean and soybean. Spherical seeds usually give more protection than flat or irregularly shaped seeds
Effect of provenance : The place where the seed crop was produced greately influences the storability.
(e.g.) Red clover seeds grown in Canada stored for 4 years with 80% germination whereas seeds grown in England and Newzealand stored only for 3 years with 80% germination. This is due to different climatic conditions and soil types prevailing in different places.
Effect of weather
Fluctuating temperature during seed formation and maturity will affect seed storage. Pre-harvest rain may also affect the viability.
Pre harvest sanitation spray
In pulses, insect infestation comes from field (e.g.) bruchids.
Seed moisture content
Most important factor influence the storability. The amount of moisture in the seeds is the most important factor influencing seed viability during storage.
Generally if the seed moisture content increases storage life decreases. If seeds are kept at high moisture content the losses could be very rapid due to mould growth very low moisture content below 4% may also damage seeds due to extreme desiccation or cause hard seededness in some crops.
Since the life of a seed largely revolves around its moisture content it is necessary to dry seeds to safe moisture contents. The sage moisture content however depends upon storage length, type of storage structure, kind / variety of seed type of packing material used. For cereals in ordinary storage conditions for 12-18 months, seed drying up to 10% moisture content appears quite satisfactory. However, for storage in sealed containers, drying upto 5-8 % moisture content depending upon particular kind may be necessary.
Harringtons thumb rule on seed moisture content :
For every one per cent decrease in seed moisture content the life of seed will be doubled. This is again hold good between 4- 12 C. Based on the tolerance and susceptibility of seeds towards moisture loss seeds are classified into
Orthodox – the seeds able to tolerate moisture loss and less seed moisture favours the storage. i.e. decreased moisture increased storage period. Eg. Rice, sorghum , and most of the cultivated species.
Recalcitrant – just opposite to the orthodox. Seeds not able to tolerate moisture loss. Required high moisture for viability maintenance.
Microflora, Insects and Mites
The activity of all these organisms can lead to damage resulting in loss of viability.The microflora activity is controlled by Relative Humidity temperature and Moisture Content of seed.
Treated seeds with fungicides can be stored for longer periods.
Fumigation to control insects will also help in longer period of stroage.
Fumigants - (e.g) methyl bromide, hydrogen cyanide, ethyline dichloride, carbon tetra chloride, carbon disulphide and napthalene and aluminimum phosphine.
Abiotic factors :
Relative humidity
Relative humidity is the amount of H2O present in the air at a given temperature in proportion to its maximum water holding capacity. Relative Humidity and temperature are the most important factors determining the storage life of seeds. Seeds attain a specific and characteristic moisture content when subjected to given levels of atmospheric humidities. This characteristic moisture content called equilibrium moisture content.
Equilibrium moisture content for a particular kind of seed at a given Relative Humidity tends to increase as temperature decreases. Thus the maintenance of seed moisture content during storage is a function of relative humidity and to a lesser extent of temperature. At equilibrium moisture content there is no net gain or loss in seed moisture content.
Temperature
Temperature also plays an important role in life of seed. Insects and moulds increase as temperature increases. The higher the moisture content of the seeds the more they are adversely affected by temperature. Decreasing temperature and seed moisture is an effective means of maintaining seed quality in storage. The following thumb rules by Harrington are useful measures for assessing the effect of moisture and temperature on seed storage. These rules are as follows.
1. For every decrease of 1% seed moisture content the life of the seed doubles. This rule is applicable between moisture content of 5-14%.
2. Fore every decrease of 5oC in storage temperature the life of the seed doubles. This rules applies between 0oC to 50oC.
Good seed storage is achieved when the % of relative humidity in storage environment and the storage temperature in degrees Fahrenheit add upto one hundred but the contribution from temperature should not exceed 50 oF.
Nomograph
Roberts (1972) developed formulae to describe the relationship between temperature seed m.c. and period of viability. From these relationships it was possible to construct a seed viability nomograph. These nomograph are helpful in predicting the retention of seed viability indefined storage environment for a particular period or to determine combinations of temperature and moisture content which will ensure the retention of a desired level of seed viability for specific period.
Gas during storage
Increase in O2 pressure decrease the period of viability
N2 and CO2 atmosphere will increase the storage life of seeds.
Seed storage sanitation or godown sanitation
• Storage environment should be free from insects and rodents
• Chemicals such as insecticides, fertilizers should not be stored along with seeds.
• Storage room should be kept coo and dry
• Fumigation may be done whenever needed
• Use wooden pallets for arranging the bags in cris-cross manner for effective ventilation on all sides of the bags.
• Seed bags should be stacked upto 6-8 tires depending upon density of seeds
• Restocking once in 3 months or less is important for prolonging seed viability
• Before storage disinfect the godowns by spraying malthion 50% E.C. @ 5 lit /100 m2 area.
• If old gunnies, cloth bags and containers are to be used these should be fumigated with aluminium phosphide.
• Size of the stack should be 30x20 feet facilitate fumigation under gas proof or polythene covers.
• Periodical inspections should be carried out and control measures to be taken i.e malthion 50% E.C. @ 5 lit /100 m2 area should be applied in every 3 weeks
• It must be borne in mind that fumigation, particularly repeated fumigation, may seriously reduce the vigour and even the germination capacity of seeds. Seeds with m.c. greater than 14% should be dried to below this value before fumigation
Maintenance of viability in storage
1. Store well mature seeds
2. Store normal coloured seeds
3. Seeds should be free from mechanical injruy
4. Seeds should be free from storage fungi or micro organisms 5. Seeds should not have met with adverse conditions during maturation 10. Storage godown should be fumigated to contro
l storage insects, periodically
6. Storage environment or godown should be dry and cool.
7. Seeds should be dried to optimum m.c
8. Required R.H. and temperature should be maintained during storage.
9. Seeds should be treated with fungicides before storage
11. Suitable packaging materials should be used for packing.
Organization set up and scope fro seed industry
Organizations involved in seed industry :
Organization set up of national and international seed companies
Managing Director
Chief of production
Production co-ordinator
Quality control Plant supervisor production manager
Operators Zonal officer
Production officer
Production Assistant
Field Assistant
Eg. Superior hybrid seed company organization set up
Board of directors
Chairman
Agri. Division
Executive Director
Production Director(Certified seed ) Production Director ( FS)
Production Officer Plan in Charge Prodn. Officer Plant operator
Field Asst. Plant supervisor farm supervisor
The process of removal of dockage in a seed lot and preparation of seed for marketing is called seed processing. The price and quality of seed is inversely related to dockage, which should not exceed a maximum level permitted for different crops for seed certification.
Due to the operation of processing the level of heterogeneity of seed lot gets narrowed down.
The heterogeneity occurs in a seed lot due to following reasons:
Variability in soil for fertility, physical, chemical and biological properties
Variability in management practices (irrigation, application of nutrients etc.)
Variability in ability of the seedling for utilizing the inputs
Variability in pest and disease infestation
Position of pod or fruit in a plant or the position of seed in a pod.
Principle of seed processing: the processing operation carried out based on the principal physical differences found in a seed lot.
Physical differences found in seed are
Physical difference Suitable machineries
1. Seed size – varied from small to bold Air screen cleaner cum grader
2. Density- ill filled, im matured to well matured Specific gravity separator
light weight to dense seed
3. Shape – round to oval and different shapes Spiral separator
4. Surface texture – smooth to wrinkled and rough Roll mill / dodder mill
5. Colour of the seed – light color to dark colors Electronic color shorter
6. Conductivity of seed – low to high Electronic separator
Requirement in seed processing
- There should be complete separation
- There should be minimum seed loss
- Upgrading should be possible for any particular quality
- There should be have more efficiency
- It should have only minimum requirement
Types of materials removed during seed processing
- Intert materials
- Common weed seeds
- Noxious weed seeds
- Deteriorated seeds
- Damaged seeds
- Other crop seeds
- Other variety seeds
- Off-size seeds
Sequence of operation in seed processing
- Sequence of operations are based on characteristics of seed such as shape, size, weight, length, surface structure, colour and moisture content. Because each crop seed possesses individually seed structure. Therefore, sequence of operation will be applied proper equipments. However, It is also involved stages following as
- Drying
- Receiving
- Pre-cleaning
- Conditioning
- Cleaning
- Separating or Upgrading
- Treating (Drying)
- Weighting
- Bagging
Storage or Shipping
Processing involved three steps :
Step 1. Pre- conditioning and pre cleaning
Pre conditioning : Isolation of seed from plant parts with which it was harvested . eg. Shelling
Pre cleaning : Removal of external materials like trash, stones, clods which are either in larger size or lighter in weight. No pre cleaning is required for hand harvested and winnowed seeds
The machineries involved in this operation are :
Scalper : Removes the larger inert matter from the seeds . If it contains a single sieve it is called as scalpers , two sieves – rough cleaners. The unit consists of a vibrating or rotating screen or sieve having perforation large enough to allow the rough seed pass through readily.
Debearders : The machine has horizontal beater with arms rotating inside a steel drum. When the seeds pass through it do the action of rubing the seeds and clip the seeds of oats, debeard barley, thresh white- cap in wheat, remove awns and beards, de hull some grass seeds and polish the seed.
Huller – scarifier : Have two rubber faced rough surfaces to rub the seeds. Dehulling ( removal of outer coat or husk) and scarifier ( scratching the seed coat) can be done simultaneously or separately.
Seed – rotating disc- centrifugal force – thrown – huller- - suction chamber- removes lighter seeds .
Maize sheller : 1. high capacity power operated shellers - bulk
2. Hand shellers – breeder or nucleus seed.
Step –2. Basic cleaning
The second stage of cleaning is carried out with air blasts and vibrating screens and is applicable to all kinds of seeds. It is essentially the same as scalping but more refined. It is performed mostly by one machine known as air-screen cleaner.
Air-Screen cleaner cum grader
The air-screen machine (Fig. 2) is the basic cleaner in most seed processing plants. Almost all seed must be cleaned by air-screen cleaner before specific specifications can be attempted. Machine size varies from small, two-screen farm models to large industrial cleaners with 7-8 screens. Two-screen models are used on farms, in breeder and foundation seed programs and by experiment stations for processing small quantities of seed. In most machines separations are made on the basis of differences in only one physical characteristic. The air-screen machine, however, effects separations on the basis of differences in size and weight of seeds. This enables the air-screen machine to use three cleaning elements: aspiration, in which light material is removed from the seed mass; scalping, in which good seed are dropped through screen openings; but larger material is carried over the screen into a separate spout; and grading, in which good crop seed ride over screen openings, while smaller particles drop through.
)
Cleaning and Grading
To obtain quality seed, it is necessary to clean the seed obtained from the farm to get rid of inert materials, weed seeds, other crop seeds, other variety seeds, damaged and deteriorated seed. Different kinds of seeds can be separated when they differ in one or more physical characteristics. Physical characteristics normally used to separate seeds are size, shape, length, weight, colour, surface texture, affinity to liquids, electrical conductivity, etc. The problem lies in identifying the most important property and use the machine that separates seed using the identified property. Some of the identified properties and machines operating by following the properties are listed below:
Name of the Separator
Property followed
Uses
Vibratory separator
Shape and surface texture
Removal of weed seeds
Spiral separator
Shape or the degree of its ability to roll
Separation of damaged/flat and wrinkled seeds from smooth seeds. Separation of mustard, rape, soybean and peas from wheat, flax, oats, etc., and round seeds from flat seeds.
Disk / Indented cylinder separator
Length
Dissimilar material like wheat, rye, mustard, barley from oats
Electrostatic separator
Electrical property
Johnson grass from sesame seed
Electronic colour sorters
Colour / brightness
Separation of off coloured seeds
Inclined draper
Shape and surface texture
Separation of smooth or round seeds from rough flat or elongated seeds
Magnetic separator
Surface texture and stickiness
Removal of contaminating weed seed from clovers, alfalfa seeds and iron metals
Roll mill
Shape and surface texture
Separation of smooth clover seed
Gravity separator or Destoner
Density or specific gravity
Removal of badly damaged, deteriorated, insect damaged crop seed and stones from good seeds.
Fig. 3. Specific gravity separator Fig. 4. Indented cylinder separator
Upgrading
Seed lots require further cleaning treatment to remove adulterants that are similar to pure seed in size and shape, to be separated by air screen cleaner. Removal of seeds larger or smaller than required size (sizing) and removal of cracked, damaged or otherwise defective seeds (grading) is accomplished in this final stage of processing.
Specific gravity separation
This method makes use of a combination of weight and surface characteristics of the seed to be separated. The principle of floatation is employed here. A mixture of seeds is fed onto the lower end of a sloping perforated table. Air is forced up through the porous deck surface and the bed of seeds by a fan, which stratifies the seeds in layers according to density with the lightest seeds and particles of inert matter at the top and the heaviest at the bottom. An oscillating movement of the table causes the seeds to move at different rates across the deck. The lightest seeds float down under gravity and are discharged at the lower end, while the heaviest ones are kicked up the slope by contact with the oscillating deck and are discharged at the upper end. This machine separates seeds of the same density but of different size and seeds of the same size but of different densities.
Indented cylinder
This helps to separate seeds according to the length. The equipment consists of a slightly inclined horizontal rotating cylinder and a movable separating trough. The inside surface has small closely spaced hemispherical indentations. Small seeds are pressed into the indents by centrifugal force and can be removed. The larger seeds flows in the centre of the cylinder and is discharged by gravity.
Magnetic separator
The magnetic separator separates seed according to its surface texture or related seed characteristics. First, seed is treated with iron filings, which adhere to rough surface alone. The treated seed lot is passed over a revolving magnetic drum and separated from smooth, uncoated seed. It may help to add varied amounts of water while mixing seed and powder, depending on the seed type. At any rate, the effectiveness of magnetic separation depends on the components of the seed lot and on the powder and water used in the treating operation. The greater the difference between surface textures of the seed lot’s components, more effective will be the separation.
Colour separator
The colour separator is used to separate discoloured seed, greatly of lower quality. Separation based on colour is necessary because the density and dimensions of discoloured seed are the same as those of sound seed, so other machines are not effective for separation. Electronic colour separation uses photocells to compare the seed colour with “background” which are selected to reflect the same light as the good seed. Seed that differs in colour is detected by the photo cells, which generate an electric impulse. The impulse activates an air jet to blow away the discoloured seed.
Friction cleaning
The air-screen combinations cannot remove debris that has a size and density similar to the seeds. However, if the debris has a different surface texture, it may be possible to remove by friction cleaning. Any object rolling or sliding over a sloping surface encounters a certain friction depending on the texture of itself and that of the sloping surface. Separation is made on a velvet cloth or rubber belt with variable inclination, which ensures that the slope necessary for the run off of the seed is different from the slope necessary for run -off of the debris. The belt continuously moves upwards and removes the debris while the seeds roll down the slope.
Spiral separator
The separator, which classifies seed according to its shape and rolling ability, consists of sheet metal strips fitted around a central axis in the form of a spiral. The unit resembles an open screw conveyor standing in a vertical position. The seed is introduced at the top of the inner spiral. Round seeds roll faster down the incline than flat or irregularly shaped seeds, which tend to slide or tumble. The orbit of round seed increases with speed on its flight around the axis, until it rolls over the edge of the inner flight into the outer flight where it is collected separately. The slower moving seed does not build up enough speed to escape form the inner flight. Most spirals have multiple inner flights arranged one above the other to increase the capacity.
Liquid flotation
Cleaning by flotation relies on the principle that the density of the seed of a given species is specific both for filled and ill filled seed. In this method, liquids with a density or specific gravity between that of the full and empty seed are used. The specific gravity of the liquids used is such that the full seed sinks and the empty seed and light debris float.
lecture no . 20 and 21 Seed Treatment
Seed-borne and early season diseases and insects pose devastating consequences to crop production if not managed. Seed Treatments playing a significant role in improving the establishment of healthy crops leading to better yields. Seed Treatments are the use and application of biological, physical and chemical agents and techniques used with seed that provide seed and plant protection and improve the establishment of healthy crops.
Nothing will work upon a poor quality seed, no matter how lavishly other inputs are spent on the crop established from such seeds. Assured germinability and vigour are important parameters to be looked upon on the seeds. Seed treatment insured both. A successful treatment should bring about
· qualitative improvement in the seed,
· improve the field performance
· and storability,
· enable mechanised sowing and
· to transform seeds as a carrier of basic inputs such as pesticides, herbicides, nutrients etc., which redefines agriculture as a profit oriented art, business or science.
History of seed treatment
Some of the first recorded uses of Seed Treatment are from the Egyptian and Roman periods and involved a technique of using sap from onion ( Allium spp.). In the middle ages, Seed Treatments were made with liquid manure and chlorine salts. Salt water treatments have been used since the mid-1600s and the first copper products were introduced in the mid-1700s. The “still used today” technology of hot water treatment is documented from as early as 1765 in Wittenberg, Germany. Seed was placed in 45oC water for 2 hours, this provided control of certain fungal pathogens on the outer surface of the seed.
A Time of Transition to Modern Seed Treatments
The seed industry is continuously in a time of transition and improvement. Key milestones in the history of Modern Seed Treatment are the introduction and ban of arsenic (used from 1740 until 1808), the introduction and ban of Mercury (used from 1915 until 1982). The launch of the first systemic compound in 1960; until then, Seed Treatments had been only seed sterilants and did not move into the plant. During the 1970’s the first systemic Seed Treatment fungicides for air-borne pathogens were introduced. In the 1990’s, new modern classes of fungicide and insecticide chemistry were launched.
Today’s Modern Seed Treatment
The objectives of modern Seed Treatment products are the superior control of certain insects and diseases while improving crop safety leading to good establishment of healthy and vigorous plants. Modern Seed Treatment formulations must also contribute to improvements in farmers’ and workers’ safety and stewardship of the environment.
Based on purpose, the types of seed treatments are
i) presowing
ii) prestorage and
iii) midstorage treatments.
Presowing Treatment
For any crop the time from sowing to seedling establishment is a crucial period in which the seed is exposed to a wide range of environmental stress that can adversely affect its performance. The presowing treatments helps the seed to cope with such problems .The presowing treatments are classified under the following :
Pre sowing Treatment
i..Dormancy breaking treatments
1. Soaking in water
2. Mechanical scarification
3. Acid scarification
4. Bio scarification
5. Scorching
6. Warm stratification
7. Cold stratification
8. Electrical seed treatment
ii. Germination augmenting treatments
1. Seed fortification/infusion
2. Dry permeation
3. Seed hardening
4. Seed priming
5. Humidification
6. Irradiation
7. Magnetic seed treatment
iii. Seed coating treatments
1. Seed pelleting
2. Seed coating / film coating
3. Seed colouring
4. Fluid drilling or gel seeding
iv. Seed protection treatments
Biological seed treatment
Seed dressing
Dormancy breaking treatments
i) Soaking in water
It refers to soaking of seeds in cold or hot water for a period ranging from few hours to several days.It is intended to break physical or chemical dormancy.
In the case of cold water soaking, seeds are soaked in cold water for one to three days; but once in 12 h water should be changed to avoid fermentation. Sometimes seeds can be soaked in running water for a day to leach out the inhibitors eg., coumarin in coriander; hydrocyanic acid in sunflower.
In the case hot water treatments, seeds should be soaked in boiled water, just removed from the heat source for one to 80 minutes.Physical dormancy caused by hard seed coat is overcome by softening of the seed coat. Chemical dormancy caused by presence of inhibitors is overcome by leaching of the inhibitors.
ii) Mechanical scarification
This denotes rubbing or aberration of seeds against hard surface.It is done to partially damage the hard seed coat.
Mode of action
During the scarification the seed coat is aberrated thereby the hard seed coat is made permeable to water.
iii) Acid scarification
Treating the seeds in sulphuric acid for a pre- standardized duration. It is done in order to overcome physical dormancy caused by hard seed coat
It is done by soaking the seeds in concentrated or diluted sulphuric acid for a pre-standardized duration with often stirring and washing the seeds for 5-10 minutes to remove all traces of acid. Shade dry the seeds.
iv) Bioscarification
It is subjecting the seeds to pretreatment by making use of animals and microorganisms as an important factor in the breakdown of seed coat impermeability. It is done to break down seed coat impermeability.
a) Animals
Pods of Acacia nilotica are fed to penned sheep or goats and the seeds are collected from the droppings. The combination of moisture, warmth and chemical action of the digestive juices softens the hard seed coat and it become permeable.
b) Insects
Termites are an important agent for breaking down seed coat dormancy in many parts of tropics as it feed and remove the exocarp eg. Terminalias.
v.)Stratification
It is a method of exposing imbibed seeds to higher temperatures for a period of
time. It is done to overcome mechanical and morphological dormancy. Soak the seeds in several times of their volume of cold water at approximately 3-5°C for 48 h. Drain off the water and mix the seeds with two to four times their volume of a moistened, water retained medium such as sand, sand peat mixture or vermiculite. Store at a warm temperature. A constant temperature of 20-25°C or alternating temperature of 20°C and 30°C is suitable for many species. Open the containers weekly, mix seeds and if surfaces show signs of drying, remoist with water spray. Periods of treatment vary form 2 weeks to 16 weeks depending on species.
vi) Cold stratification
It is a method of exposing imbibied seeds to lower temperatures for a period of
time. It is done to overcome physiological dormancy.Seeds should be soaked in several times their volume of water before prechilling, at 3-5°C for 48 h. After soaking, the water is drained off and moist seeds are stored at 3-5°C for the period appropriate to each species. Storage may be without any medium i.e. seeds as such or the seeds may be mixed with 2-4 times its volume of a medium such as moist sand, peat or a mixture of these two. Containers shall be opened and mixed if surfaces dry off. eg., Abeis spp, Eucalyptus delegatensis etc.
Germination augmenting treatments
i) Seed fortification/infusion
It is process of enriching the seeds with bioactive chemicals for improving the germination and seedling vigour
To the known volume of seeds one third volume of the nutrient solution is added and allowed to imbibe for short duration. The imbibed seeds should be dried under shade.
ii) Dry permeation
It is soaking of seeds in organic solvents like acetone, petroleum ether and dichloromethane containing desired hormonal and non hormonal chemicals for 2-3 h followed by evaporation of the solvent in air. It is an approach to improve the germinability and vigour of the seed by infusion of bioactive chemicals into the seed without altering seed moisture content.
iii) Seed hardening
It is the process of hydrating the seed to initiate the pre-germinative metabolism followed by dehydration which fixes the biochemical events. It is done in order to impart resistance against stress conditions viz., drought and cold, to the emerging seedlings
Seeds or grains are allowed to take up a certain amount of water, and then they are kept moist at 100 - 250C for several hours before drying in a steam of air. The best results can gain in two - three cycles of wetting and drying, although for some one cycle is sufficient. Different amounts of water are recommended for different species and cultivars of seed or grain.
iv) Seed priming
It is the process of controlled hydration of seeds to a level that permits pre-germinative metabolic activity to proceed, but that prevents actual emergence of the radicle.
Seeds are soaked in variety of solutes, including solutions of various inorganic salts, sugars and polyethylene glycol (PEG) a chemically inert, high molecular weight compound does not penetrate the cell walls. The temperature suggested during priming is between 100 - 150C. The duration of priming varies with the crop.
Heydecker et al (1973) used different terms depending upon the methods adopted for priming.
(i). Osmopriming - Soaking the seeds in osmotic solutions
(ii) Halopriming - Soaking the seeds in salt solutions
(iii) Biopriming - Coating the seeds with biological agents like bacteria
(iv) Solid matric priming - This consists of mixing seeds with an organic or inorganic carrier and water for a period of time. The moisture content of the matric is brought to a level just below what is required for radicle protrusion. Seed water potential is regulated by the matric potential of the seed and during priming the water is largely held by the carrier. Seeds can imbibe water from the carrier till the equilibrium is reached.
vi) Irradiation
Presowing irradiation of the seeds is a novel measure to increase the yield potential by improving germination and vigour. Air dried seeds are irradiated by using experimental gamma units. The unit consists of a definite configuration of irradiator such as a hollow cylinder or a linear or flat irradiator and maintaining an accurate time exposure for conducting the experiment.
In the process of the growth and development of plants raised from irradiated seeds, beginning from seedling emergence and ending with the ripening, there appears new, quite diverse changes manifested in the acceleration of the cell division rate, enhancement of growth and development, change of organogenesis, yield increase and its quality change, ie., there emerges a very complicated sequence of changes which has been termed as the effect of distant irradiation action.
vii) Magnetic seed treatment
It is a simple treatment which involves exposure of seeds to a magnetic field to improve germination and vigour for specified duration.
Magnetically treated seeds respire slowly but register higher respiration quotient values with increased enzyme activity viz., α -amylax and nitrate reductase
Seed coating treatment
i) Seed pelleting
It is the process of enclosing the seed inside a small quantity of inert material just large enough to produce a globular unit of standard size
Seeds are introduced into a coating drum or pan that resembles a cement mixer. An amalgam of pelleting materials (clays, limestone, calcium carbonate, talc, vermiculite) and cementing adhesives (gum arabic, gelatin, methylcellulose, polyvinyl alcohol, polyoxylethylene glycol-based waxes) are used to form the pellet and other compounds such as innoculants, fungicides, etc. may be added to enhance seed performance. As drum rotates, the seeds are first sprayed with water followed by the addition of the pelleting materials with binder. The wet seed attracts and becomes coated with the dry pelleting material and the pellet gradually increases in size with each turn of coating drum . Longer rotation times with greater amounts of pelleting materials lead to greater pellet size and roundness. At the end of the pelleting process, a binder is added to harden the outer layer of the pellet.
The ingredients of the seed pellets exerts respective positive influence on seed performance eg., Diammonium phosphate stimulates prolific root growth.
.ii) Seed coating / film coating
It is a process of applying useful materials to form a continuous layer of this coating over seed without altering the shape or size. The advantage of film coating over other coating process is the absence of dusting off “Problem and improvement of seed flow in planting equipment.
The application of seed coating is very similar to the slurry seed treatment and similar equipment is used, where in the seeds are sprayed or dipped in the dissolved additives and immediately dried film coating involves application of additives dissolved in a dyed solution of a ‘stickly’ polymer and immediately dried.
The ingredients of the seed coating excerts respective positive influence of the on seed performance eg., Bavistin protects the seedling from wilt disease
iii) Seed colouring
Colouring of seeds using natural or artificial dyes. It is done to
· to prevent inadvertent use of treated seeds for food or feed purposes
· to identify the seeds eg., A line, Bline, Rline etc.,
· to project their seed in the market eg. Private companies
The seeds are sprayed or dipped in the dissolved dyes
iv) Fluid drilling or gel seeding
It is mixing of pre germinated seed in a viscous gel, which is sown with an appropriate droll to maintain the seed moisture of the pre geminated seeds and to prevent injury to emerged radical.
Seeds are germinated in aerated water until radicle emergence and then they are mixed in a viscous gel eg., alginate gel. The viscous gel provides a cushion to the emerged radicle thus preventing any mechanical damage during drilling. The gel also gives a protective covering to the seed against any moisture loss.
v) Seed protection treatments
They are the treatments that use beneficial microorganisms to offer the potential for sustained plant growth.It can serve two purposes viz., seed protection and nutrient supplementation.Seeds are mixed with adhering such as rice gruel, and coating with the specific biological strains in appropriate proportions followed by surface drying.
Seed protection : Fungi such as Trichoderma, Pythium and Chaetomium controls damping off and other diseases. The bacterium clavibacter xylli cocuteracts European comporer by producing an insecticidal protein.
Nutrient supplementation : the bacteria such as Rhizobium and Azespirillum enhances root nodulation and increases nitrogen fixation
success is depends on
· the efficacy of biocontrol,
· the number of propogules added to the seed,
· the method of application and
· the control of other microbes in the application process.
vi) Seed dressing
It refers to the application of pesticides( fungicides, insecticides or a combination of both) to seeds before sowing in order to protect the seeds and young seedlings from soil borne pathogens..
Seeds are thoroughly mixed with required quantities of chemicals eg., Thiram and captan @ 2 g/kg of seeds or botanicals eg., leaf powder of Azadirachta indica and Vitex negundo
Pre storage treatments
The treatments given to the seeds prior to or during storage to protect the seed from deteriorative changes and from pest and diseases are called pre storage treatments. The types of pre – storage seed treatments are
1. Halogenation
2. Antioxidant treatment
3. Seed sanitation
4. Seed fumigation
i) Halogenation
a) Dry dressing
It is application of halogens like chlorine, bromine and iodine to seeds before storage as dry dusting to stabilize the lipoprotein biomembrane.
Procedure : Calcium carbonate, fresh chalk, talc charcoal or activated clay are first exposed to vapours of halogens and alcohols @ 2-5 g /Kg seed. An alternative method is to add the chemicals directly to the carrier ( 50 – 500 mg of chemical added to 2-5 g carrier for treating 1 Kg seed) in a closed container. Calcium carbonate has proved to be a good carrier. After equilibrating the carrier- chemical mix the seed is thoroughly dressed with the same and kept for 24-72 h in the closed container and thereafter stored in the usual way .Bleaching powder ( calcium oxy chloride ) may be directly mixed with the seed at the rate of 1-4 g / Kg seed.
b) Vapour treatment
Exposure of seeds to halogen vapour in a closed container for 16-72 h, to very low concentrations of halogens The concentration of chemicals and the time of exposure would depend on the material concerned.
ii) Antioxidant treatment
Application of antioxidants such as vitamin A,C,E, butylated hydroxytoluene (BHT) to seeds before storage as wet or dry treatments which delays the physiological ageing.The seeds are applied with antioxidants through soaking in respective solutions at particular concentration
Antioxidants such as vitamin A,C and E provides hydrogen atom for quenching the lipid radical thereby putting an end to free radical propagation and subsequent damage to cell membrane and ultra cellular structures.
.
ii) Seed sanitation
The seed sanitation treatments refers to the application of pesticides (fungicides, insecticides or a combination of both) to seeds to disinfest and disinfect them from various seed borne and soil borne pathogenic organisms and storage insect pests to safe guard the seed and seedlings against the seed and soil borne pathogens..Seed borne pests and diseases may be carried within seeds or on seeds or they may accompany the seed as free living organisms or in debris.
The seeds are simply dipped or soaked in the chemical solutions and the fungicides applied as dust, slurry or liquid in recommended concentrations.
a) Seed disinfection
This refers to the eradication of fungal spores that have become established within the seed coat or in more deep-seated tissues. For effective control the fungicidal treatment must actually penetrate the seed in order to kill the fungus that is present.
b) Seed disinfestation
This refers to the destruction of surface borne organisms that have contaminated the seed surface but have not infected the seed surface.
iv) Seed Fumigation
It is a process of exposing the seeds to fumigants (gaseous form of chemical) to control seed borne fungi and insects which cause seed deterioration during storage.
The seeds should be brought to equilibrium moisture contents at 60 per cent RH, then they should be enclosed in air tight containers and fumigated at temperature of 27±1.5 oC for required durations. After fumigation seeds placed in cloth bags are aerated for 21 weeks under room condition. Subsequent second and third fumigations are repeated after 3 and 6 months after first fumigation. Examples of fumigants are ethylene oxide, aluminium phosphide, calcium cyanide, ethylene dichloride and carbon tetrachloride, ethylene dibromide, carbon disulphide or hydrogen phosphide.
The toxic effects on the fumigants bring about the control of fungi or insects. The fumigant can penetrate into the seeds to control the deep-seated pathogens.Before going for fumigation a thorough knowledge of seed moisture level and type of infestation, choice of fumigant, its doses and exposure time and necessity of number of fumigation is very essential.
Mid storage treatments
Seeds in storage accumulate damage to cell membranes during senescence .Mid storage seed treatments are capable of reducing the age induced damages and restoring the seed vigour to a certain extent besides, the seed viability and productivity of stored seeds are also improved.
i)Hydration – Dehydration
It is the process of soaking the low and medium vigour seeds in water with or without added chemicals usually for short durations to raise the seed moisture content to 25 – 30% and drying back the seeds to safe limits for dry storage.
Types of H-D treatments
The wet treatments include soaking-drying, dipping-drying, spraying-drying, stepwise hydration-drying, moisture equilibration-drying, moisture equilibration soaking-drying, moist and conditioning-drying, etc. The choice of the treatment depends upon the characteristics of seed and initial vigour status of the seeds.
Soaking – Drying (S-D)
Stored seed is soaked in water or solution of chemicals sufficient to cover it and kept at room temperature for 2-6 hour depending on the material with occasional stirring. The soaked seed is taken out and after surface drying in the shade for some time, dried back to the original moisture content Dilute solution of chemicals such as sodium or potassium phosphate (di and mono basic), sodium chloride, p-hydroxy benzoic acid, p-amino benzoic acid, oxalic acid, potassium lodide, etc can also be used at 10-4 to 10-3 M concentrations. Fungicidal and insecticidal formulations can also be incorporated in the soak water.
Dipping – Drying (D-D)
Seeds are dipped in water or solutions of the aforesaid chemicals for only 2-5 minutes and the wet seed is taken out immediately and kept covered for 2 – 6 hours depending on the material, for absorption of surface water followed by drying back in S-D. This treatment is effective in most high and high-medium vigour seeds of rice, wheat, jute, summer and winter vegetables
Spraying – Drying
Seeds are spread in a thin layer and then an amount of water (approximately 1/5 to ¼ of the seed weight) is sprayed on to it in two equal installments (turning over the seed layer after the first spray) and then kept covered by a polythene sheet for 2-4 hours before drying back. This treatment is similar to D-D in its efficacy and suitability.
Moisture equilibration – drying (ME – D)
Here, the seeds are placed in thin layers on trays kept on a raised platform in a closed moisture saturated chamber lined internally with moist blotters giving nearly 100% RH at room temperature. After 24-48 hours, depending on the material and ambient temperature, the seed is dried back in the usual way. For soaking injury prone seeds this treatment, which gives a slow and progressive rise in moisture content, is very effective. ME-D, however, difficult to practice on a large scale and is not advocated for low vigour non leguminous seeds because of possible aging effect of the treatment especially when given for prolonged periods.
Moist sand conditioning – drying (MSC-D)
This treatment is similar to the moisture equilibration treatment but easier to practice. For slow and progressive moisture uptake, the seed is thoroughly mixed with pre-moistened sand, using 3 times the amount of air dry sand than seed. Moisture content of sand is adjusted to 5-10 by adding the requisite amount of water or solution of chemicals to previously washed and dried fine grain building grade sand. The addition of water should be so adjusted as to get the required hydration effect without initiating the germination process. After mixing the dry seed with the premoistened sand, the mixture is kept at room temperature for 16 – 36 hours depending on the material and sand moisture content. The seed absorbs moisture from sand and after incubation the hydrated seed is separated from sand by sieving and dried back to the original weight.
Mode of Action The main purpose of hydration is to raise the seed moisture content to 25 –30% (wet weight basis) before drying back to safe limits for dry storage. The hydration - dehydration treatment may improve the vigour by controlling free radical reactions and consequent peroxidative damage to lipoprotein cell membranes.
The hydration – dehydration treatments
1. should be given only to stored seeds.
2. is effective in low and medium vigour non- leguminous seeds,
3. the moisture equilibration and moist sand conditioning treatments in which moisture is taken up by the seed in a slow and progressive manner, are recommended for relatively high- vigour seeds and seeds of pulses and leguminous vegetable crops
6. Direct soaking of leguminous seeds should be avoided.
7. would not make a seed germinable, which has already lost viability.
Lecture No. 22 and 23 Seed certification
It is a legally sanctioned system for quality control and seed multiplication and production. It involves field inspection, pre and post control tests and seed quality tests.
Purpose of seed certification
To maintain and make available to the farmers, through certification, high quality seeds and propagating materials of notified kind and varieties. The seeds are so grown as to ensure genetic identity and purity.
Eligibility for certification of crop varieties
Seed of only those varieties which are notified under section 5 of the Seeds Act, 1966 shall be eligible for certification.
Breeder seed is exempted from certification. Foundation and certified class seeds come under certification.
Seed Certification Procedures or Phases of Seed Certification
1. Receipt and scrutiny of application
2. Verification of seed source
3. Field inspection
4. Post harvest supervision of seed crops
5. Seed sampling and testing
6. Labelling, tagging, sealing and grant of certificate
I. RECEIPT AND SCRUTINY OF APPLICATION
i. Application for registration
Any person, who wants to produce certified seed shall register his name with the concerned Assistant Director of Seed Certification by remitting Rs.25/- per crop, per season. There are 3 seasons under certification viz.,
kharif (June - September),
rabi (October - January) and
summer (February - May).
The applicant shall submit two copies of the application to the ADSC 10 days before the commencement of the season or at least at the time of registration of sowing report. On receipt of the application, the Assistant Director of Seed Certification will verify the time limit, varietal eligibility and its source, the class mentioned, remittance of fee etc., The application, if accepted will be given an application no (e.g. Paddy / k/01-97-98 where paddy refers the crops to be registered, K the season, 01-the application Number and 99-2000 the financial year). The original application is retained and the duplicate is returned to the applicant.
b. Sowing report (Application for the registration of seed farm)
The seed producer who wants to produce certified seeds shall apply to the Assistant Director of Seed Certification in the prescribed sowing report form in quadruplicate with prescribed certification fees along with other documents such as tags to establish the seed source.
Separate sowing reports are required for
a. different crop varieties, different classes,
b. different stages
c. if the seed farm fields are separated by more than 50 meters.
d. if sowing or planting dates differ by more than 7 days and
e. if the seed farm area exceeds 25 acres.
The sowing report shall reach concerned Assistant Director of Agriculture Seed Certification within 35 days from the date of sowing or 15 days before flowering whichever is earlier. In the case of transplanted crops the sowing report shall be sent 15 days before flowering. The producer shall clearly indicate on the reverse of sowing report,
the exact location of the seed farm
crops grown on all four sides of the seed farm etc.,
to facilitate easy identification of the seed farm by the seed certification officer.
The Assistant Director, Seed Certification on receipt of the sowing report, scrutinises and registers the seed farm by giving a Seed Certification number for each sowing report. Then he will send
one copy of the sowing report to the Seed Certification officer,
one to the Deputy Director of Seed Certification
third to the producer and
he retains the fourth copy.
Verification of seed source
During his first inspection of seed farm the Seed Certification officer will verify whether the seed used to raise the seed crop is from an approved source and correct class of seed.
Field inspection
Objective
The objective of conducting field inspection is to verify the factors which can cause irreversible damage to the seed crop on genetic purity.
Inspection authority
The seed certification officer authorized by the registering authority shall attend to field inspections
Stages of Inspection
The number of field inspections and the stages of crop growth at vary from crop to crop and depends upon duration and nature of pollination of the seed crop.
If the crop is grown for hybrid seed production, the number of field inspections during the flowering stage should be more than one.
In hybrid seed production and variety seed production of cross pollinated crops the inspection during flowering should be made without any prior notice of the seed grower to judge the quality of operation undertaken by him to maintain the genetic purity of the crop. If prior notice is given to the seed grower, it may not be possible to detect the damage by the contaminants
But in the case of self-pollinated crop the seed grower may be informed about the date of inspection. Prior notice will lead to improvement of the quality of the seed through rogueing.
The key points to be observed at each stage of inspection
Stage of crop
Key points to be observed at inspection
I. Pre flowering stage
(Vegetative Stage)
II. Flowering Stages
(May be II and III inspections when 50% of plants begin to flower).
a. Verification of seed source
b. Confirmation of acreage given in the report.
c. Isolation distance
d. Planting ratio
e. Border rows
f. Guide the grower in identification of offtypes, pollen shedder, diseased plants, shedding tassels etc.,
a. Confirm the observation of prior inspection
b. Confirm whether grower had continued thorough rouging, after the previous inspection.
c. Verify the removal and occurrence of offtypes, pollen shedders, shedding tassels, objectionable weed plants and diseased plants
III. Inspection during post flowering and pre-harvesting stage.
IV. Inspection during harvest
(This is the last inspection conducted on a seed crop).
a. Confirm the correctness of observations, made in earlier inspections.
b. Guide the grower on rouging, based on pods, earhead, seed and chaff characters such as colour, shape and size.
c. Explain to the grower when and how to harvest the crop and process.
a. Verify that male parent rows have been harvested separately.
b. Ensure complete removal of offtypes, other crops, weeds and diseased plants etc.,
c. Seal properly by the certification agency of the threshed produce after initial cleaning and drying.
d. Instruct the seed growers for safe storage and transportation.
Minimum number of field inspections required for different crops for certification
CROP
minimum No.of inspections
STAGES OF CROP
Paddy and Wheat
2
Flowering to harvest
Sorghum
Hybrid
4
Ist before flowering
IInd and
IIIrd during flowering
IVth prior to harvest.
Varieties
3
Ist before flowering
IInd during flowering
IIIrd prior to harvest
Maize
Inbred lines Single crosses
Other hybrids
4
Ist before flowering
Rest during flowering
Varieties
2
Ist before flowering
IInd during flowering
Bajra
Hybrids
4
Ist before flowering
IInd and IIIrd during flowering
IVth prior to or during harvest.
Varieties
3
Ist before flowering
IInd during 50% flowering
IIIrd prior to harvest
PULSES
Green gram,redgram
Black gram , cowpea
2
Ist before flowering
IInd flowering and fruiting stage
Groundnut
2
Flowering to harvest
Sesame
3
Ist before flowering IInd during flowering
IIIrd from fruit maturity to harvest
Sunflower
2
Flowering to harvest
Rape and mustard
3
Ist before flowering
IInd during flowering to fruiting
IIIrd from maturity to harvest
Soybean
2
Flowering to harvest
Castor
2
Flowering to harvest
Cotton (Varieties)
(Hybrids)
2
4 Flowering to harvest
Ist before flowering
IInd and IIIrd during flowering
IVth during harvest
Brinjal
Tomato
Chilli
Bhendi
3
Ist before flowering
IInd during flowering to fruiting
IIIrd during maturity.
Carrot
3
Ist early (20-30 days after sowing)
IInd when lifted and replanted
IIIrd during flowering
Cabbage
3
Ist before marketable stage
IInd when the heads have formed
IIIrd during flowering
Cauliflower
4
Ist before marketable stage
IInd during curd formation IIIrd when most plants have formed curds
IVth during flowering
Onion (seed to seed)
3
Ist during early vegetative stage IInd during bulb formation
IIIrd during flowering
Field counts
The purpose of field inspection is to find out field standards of various factors in the seed farm. It is impossible to examine all the plants in the seed farm. Hence, to assess the field standards random counting is followed.
Points to be observed before counting
1. All plants falling in each count must be examined for each factor
2. In hybrid seed field the prescribed number of the field counts should be taken in each parent separately.
Sources of contamination or factors to be observed
The contaminants are
1. Physical contaminants - inseparable other crop plants, objectionable weed plants and diseased plants
2. Genetical contaminants -. Consists off-types, pollen shedders and shedding tassels.
a. Off type -Plant that differs in morphological characters from the rest of the
population of a crop variety.
Off type may belong to same species or different species of a given variety. Plants of a different variety are also included under off types.
b. Volunteer plant- plants from a previous crop
c. Pollen shedders –presence of 'B' line in 'A' line.
d. partials - Some times 'A' line produce fertile anthers are called partials. These
partials are also counted as pollen shedders.
No.of counts :
It is necessary to take minimum of 5 counts upto 5 acres and an additional count for every 5 acres or part of as given below.
Area of the field (in acres)
up to 5
5
6-10
6
11-15
7
16-20
8
21-25
9
Double count
In any inspection. if the first set of counts shows that the seed crop does not confirm to the prescribed standard for any factor, a second set of counts should be taken for the factor.
However, when the first set of counts shows a factor more than twice the maximum permitted, it is not necessary to take a second count.
On completion of double count assess the average for the two counts. It should not exceed the minimum permissible limit.
Number of plants for a count
S.No
Crop
Number of plants / heads per count
Remarks
1
Soybean, Jute, Lucerne, Mesta, Berseem
1000 plants
Closely planted crops
2
Beans, cluster beans, cowpea, green gram, black gram, peas, mustard, sesame, bengal gram, safflower, niger
500 plants
Medium spaced crops
3
Bhendi, brinjal, chilli, castor, cole crops, cotton, cucurbits, ground nut, miaze, potato, red gram, tomato and sunflower
100 plants
Wide spaced crops
4
Bajra, barely, oats, paddy, wheat, ragi, sorghum
1000 heads
Tillering crops
Shedding tassels
These plants which shed pollen in female parent rows. When 5 cm or more of the entire spike, which shed or shedding are counted.
Inseparable crop plants
These are plants or different crops which have seed similar to seed crop
Crop
Inseparable crop plants
Wheat
Barely, oats, gram and triticale
Barely
Oats, gram, wheat and triticale
Oats
Barely, gram, wheat and triticale
Triticale
wheat, barely, oats, gram and rye
f. Objectionable weed plants
These are weeds
1. Whose seeds are difficult to separate once mixed
2. Which are poisonous
3. Which have smothering effect on the main crop
4. Which are difficult to eradicate once established
S.No
Crop
Common name of the weed
Botanical name
1
2
3
4
5
6
Paddy
Wheat
Sunflower
Bhendi
Rape and mustard
Lucerne
Wild rice
Wild morning glory
Wild sunflower
Wild okra
Mexican prickly poppy
Dodder
Oryza sativa var fatua
Convolvulus arvensis
Helianthus spp
Abelmaschus spp
Argemone mexicana
Cuscuta spp
Designated diseases
The diseases which may reduce the yield and quality of seeds are termed as designated diseases.
S.No.
Crop
Name of the disease
Casual organism
1
2
3
4
5
6
7
8
9
10
Wheat
Sorghum
Pearl millet
Cowpea
Greengram
Gingelly Sunflower Loose smut
Brinjal
Chilli
Tomato
Grain smut
Head smut
Ergot
Grain smut
Downy mildew
Anthracnose
Halo blight
Leaf spot
Downy mildew
Phomopsis blight
Leaf blight
Anthracnose
Early blight
Leaf spot
Tobacco mosaic virus
Ustilago tritici
Sphacelotheca sorghi
Sphacelotheca reiliana
Claviceps microcephala
Tolyposporium pencillariae
Scelerospora graminicola
Colletotrichum lindemuthianum
Psedomonoas phasiolicola
Cercospora sesami
Plasmopara halsterdii
Phomopsis vexans
Alternaria solani
Colletotrichum capsici
Alternaria solani
Stemphylium solani
(TMV)
Land requirement
The field offered for certified seed production should not been grown in the previous season with the same crop. If it was grown, the variety should be the same. In that case, the field should be irrigated at least 3 weeks before sowing and ploughed just prior to sowing, in order to destroy germinating seeds.
Isolation
Separation of seed fields from
fields of other varieties of the same crop,
same variety fields not confirming to varietal purity requirements
other related species fields and
fields affected by diseases to prevent genetic and diseases contamination.
The minimum distance to be maintained between the seed crop and the source of contaminant is called isolation distance.
Inspection report
The seed certification officer after taking field counts and comparing them with the minimum field standards, the observations made on the seed farm field should be reported in the prescribed proforma to
1. Deputy Director of Agriculture (Seed Certification)
2. To the Seed Producer
3. Assistant Director of Agriculture (Seed Certification) and
Fourth copy retained with see certificate officer
Assessment of seed crop yield
It is necessary to avoid malpractice's at the final stage during harvest operation. The seed certification officer is expected to fix the approximate seed yield.
Liable For Rejection Report (L.F.R)
If the seed crop fails to meet with any one factor as per the standards, Liable for Rejection report is prepared and the signature of the producer is obtained and sent to Deputy Director of Agriculture Seed Certification within 24 hours.
Re-inspection
For the factors which can be removed without hampering the seed quality, the producer can apply for re-inspection to the concerned Deputy Director of Agriculture Seed Certification within 7 days from the date of first inspection order. For reinspection half of the inspection charge is collected.
Post harvest supervision of seed crop
The post harvest inspection of a seed crop covers the operations carried out at the threshing floor, transport of the raw seed produce to the processing plant, precleaning, drying, cleaning, grading, seed treatment, bagging and post processing storage of the seed lot.
Pre-requisites for processing
1. Processing report should accompany the seed lot
2. It should be correlated with the estimated yield
3. Seed should be processed only in approved processing unit.
4. ODV test for paddy should be done at the time of sealing and issue of processing report or before processing. If the result exceeds 1% of the produce may be rejected.
5. Field run seed should be brought to the processing unit within the 3 months from the date of final inspection. Processing and sampling should be done within 2 months in oil seed crops and 4 months for other crops from the date of receipt in the processing unit.
In cotton the kapas from the passed lot should be moved to the ginning factory within 5 days from the date of issue of processing report. The ginning should be done within 3 months from the date of final harvest inspection report. Ginned seeds should be moved to seed processing unit within in 5 days of ginning. Inspection and sampling should be done within 3 months after ginning.
Intake of raw produce and lot identification
The seed certification officer in-charge of the seed processing plant may, after verification of the above stated documents and total amount of seed accept the produce for processing. After verification he should be issue a receipt to the seed grower. Each seed lot has to be allocated a separate lot number for identification.
Seed sampling and testing
During packaging Seed Certification officer will draw samples according to ISTA Procedure and send the sample to Assistant Director of Agriculture (See Certification) concerned within a day of sampling. The ADASC will in turn send the sample to the Seed Testing Laboratory within 3 days of receipt of the sample to testing seed standards viz., physical purity, germination, moisture content and seed health as prescribed. The Seed Testing Officer will communicate the result to the ADASC concerned within 20 days. On receipt of the analytical report the ADASC will communicate the result to the producer and Seed Certification officer.
Labelling, tagging, sealing and grant of certificate
After receiving the seed analytical report the Seed Certification officer will get the tag from the ADASC and affixes labels (producer's label) and tags (blue for Certified Seed and White for Foundation Seeds) to the containers and seals them to prevent tampering and grants certificate fixing a validity period for 9 months. Tagging should be done within 60 days of testing.
Resampling and reprocessing
When a seed lot does not meet the prescribed seed standards in initial test, on request of the producer Seed Certification Officer may take resample.
If the difference in germination analysed and required is within 10, then straight away resampling can be done. If it is >10, reprocessing and resampling may be done.
The producer should request the Seed Certification Officer concerned in writing within 10 days from the receipt of the result. No charge is collected for resampling.
When a seed lot, fails even after free sampling reprocessing can be taken upon special permission from Deputy Director Seed Certification. For such reprocessing a fee of Rs.20/- Q and lab charges Rs.10/- Q is collected.
SEEDS ACT AND RULES
Introduction
The seed is an important agricultural input and it plays vital plays vital role in increasing production and productivity. There is a need to safeguard the farmers with the supply of genetically pure and quality seeds. Any new variety produced by the Scientist has to be multiplied to many times to meet the needs of the farmers. In order to ensure the availability of quality seeds, Government of India have enacted seeds act 1966 and seed rules, 1968. The seed (Control) order 1983 promulgated under essential commodities act, 1955 in order to ensure the production, marketing and equal distribution of the seeds.
Seeds Act 1966.
The object of Seed Act is for regulating the quality of certain notified kind / varieties of sees for sale and for matters connected therewith. The seed act passed by the Indian Parliament in 1966 was designed to create a 'Climate' in which the seeds man could operate effectively and to make good quality seed available to cultivators. Seeds rule under the act were notified in September 1968 and the act was implemented in its entirely in October 1969. This act extent to the whole of India and it has 25 sections.
Seed legislation could broadly be divided into two groups
1. Sanctioning legislation
Sanctioning legislation authorities formation of advisory bodies, Seed Certification Agencies, Seed Testing laboratories, Foundation and Certified Seed Programmes, Recognition of Seed Certification Agencies of Foreign countries appellate authorities.
2. Regulatory legislation
Regulatory Legislation controls the quality of seeds sold in the market including suitable agencies for regulating the seed quality.On quality control basis, the Seeds Act could conveniently be divided into the following:
I. Minimum limit and lablelling of the notified kind / varieties of seed
a. Power to notify the kind / variety
b. Labeling provisions
c. Seed testing
d. Seed analyst
e. Seed inspectors
f. Penalty
g. General provisions
II. Seed Certification
III. Restriction of Import and Export of Seeds
1. Minimum limits and labelling
Quality control as envisaged in the Act is to be achieved through pre and post marketing control, voluntary certification and compulsory labelling of the seeds of noticed notified kind / varieties.
(a) Power to notify the kind / varieties
New varieties evolved by the State Agricultural Universities and ICAR institutes are notified and release /notified respectively under section 5 of the seeds act in consultation with the central seed committee and its sub committees constitute under section 3 and 3(5) of the Seeds Act. As on date more than 2500 varieties and 130 varieties were notified and denotified under this section.
List of varieties notified and denotified from 1969 to 1965 are compiled and made available in the form book called catalogue of varieties notified and denotified under section 5 of the Seeds Act functions of the Central Seed Committee and its sub-committee are defined in Clauses 3 and 4 of part II of seed rule.
(b) Labelling provision
Minimum limits for germination, physical purity and genetic purity of varieties / hybrids for crops have been prescribed and notified for labelling seeds of notified kind / varieties under section 6(a) of the Seeds Act. Size of the label, colour of the label and content of the label were also notified under sub clause (b) of Section 6 of Seeds Act. Colour of the label is opoline green and size of the label is 10 cm x 15 cm or proportionate thereof. Responsibility for making labelling content of mark or label, manner of marking, false / misleading statement on label etc., are defined under clause 7,8,9,10,11 and 12 of part V of seeds rule.
Section 7 of the act regulates the sale of notified kind or varieties. Accordingly no person shall keep for sale, offer to sell, barter or otherwise supply any seed of any notified kind or variety, after the dates recorded on the container mark or label as the date unto which the seed may expected to retain the germination not less than prescribed undr clause (a) of section 6 of the Act.
Seed Testing
There is a provision to set up a central seed laboratory and state sees laboratory to discharge functions under section 4(1) and 4(2) of the Seed Act, In the year 1968 there were 23 state seed testing laboratories in the country. At present there are 86 Seed testing laboratories functioning in the country. During 1995-96 these laboratories tested about 5 lakh samples. Seed Testing laboratories have been assigned certain important functions under part III (5) of Seed Rule.
Seed Analyst
State Government could appoint the Seed Analysts through notification in the Official Gazette under Section 12 of the Seed Act defining his area and his jurisdiction. Seed Analyst should posses certain minimum qualification as prescribed under clause 20 part IX of Seed Rule. Seed Inspectors Classes of seed
The State Government, under section 13 of the Act may appoint such a person as it thinks fit, having prescribed qualification (Clause 22 part IX of Seed Rule) through notification, as a Seed Inspector and define the areas within which he shall exercise jurisdiction for enforcing the seed law. He will be treated as a public servant with in a meaning of section 21 of the I.P.C. (45 of 1860).
He has power to examine records, register document of the seed dealer. He will also exercise such other powers as may be necessary for carrying out the purposes of this Act or rule made thereunder. Duties of Seed inspectors are defined in clause 23 of part IX of Seed rule.He can issue stop sale order in case the seed in question contravenes the provision of relevant Act and rules for which he can use form No.III. When he seizes any record, register documents or any other material , he should inform a magistrate and take his order for which he can use form No.IV.
Penalty
If any person, contravenes any provision of the Act or Rule, or prevents a seed inspector from taking sample under this Act or prevents a Seed Inspector from exercising any other power conferred on him could be punished under section 19 of the act with a fine of five hundred rupees for the fist offence. In the event of such person having been previously convicted of an offence under this section with imprisonment for a term, which may extend to six months or with fine, which may extent to one thousand rupees of with both.
Seed certification
The object of the Seed Certification is to maintain and make available to the public through certification high quality propagating material of notified kind / varieties so grown and distributed as to ensure genetic identify and genetic purity. The certified standards inforce are Indian Minimum seed certification standards and seed certification procedures form together for the seed certification regulations.
Seed of only Seed if only those varieties which are notified under section under Section 5 of the seeds act shall be eligible for certification.
• Breeder seed
• Foundation seed
• Certified Seed
Breeder seed
• Breeder seed is a seed directly controlled by the breeder.
• Breeder seed should be genetically so pure as guarantee that in the subsequent generation.
• Breeder seed could not come under the purview of seed certification as it is not meant for public sale.
• Breeder seed should be packed and supplied with breeder's golden yellow tag. It is also the fact no standard for breeder seed have been prescribed.
Foundation seed
• Foundation class of seed and certified class of seed are to be certified by the Certification Agencies as per the Indian Minimum Seed Certification Standards.
• Section 8 of the Seeds Act provide state government or the Central Government consultation with State Government may be notification in official gazette, established certification agencies for the state to carry out the functions entrusted to certification agency by or under this Act (Part IV, clause 6, part VI clause 14 of Seeds Rule).
Certified seed
• Seed act section 9 provides any person desires of producing certified seed shall register his name with concerned seed certification agency duly remitting the prescribed fee in form No.1 for grant of certificate. Certificate could be granted in form No.11 after meeting the requirement of certification agency prescribed under Part VII clause 15,16 and 17 of Seed rule.
• It should have the minimum genetical purity of 99%
• Certified seed may be the progeny of certified seed , provided this reproduction does not exceed two generations beyond foundation seed and provided that if certification agency determines the genetic and physical purity, if not be significantly altered
• In case of highly self pollinated crops certification of one further generation may be permitted
• Certified seed produced from certified seed ,shall be eligible for further seed increase under certification, except in case of highly self pollinated crops, where certification of one further generation may be permitted
• Certification tags issued once for certified seed not eligible for further seed increase under certification
• For paddy and wheat, certified seed produced from certified seed is eligible for certification by NSC up to two generations from foundation seed
Seed (Control) order, 1983
Restriction of Export and Import of Seeds
There is a provision to restrict export and import of seeds of notified kinds or varieties. The section 17 define as under
" No person shall for the purpose of sowing or planting by any person (including himself) export or import or cause to be exported or imported any seed of any notified kind or variety unless. a) It conforms to the minimum limits of germination and purity specified for that seed under clause (a) of Section 6 and
b) Its container bears in the prescribed manner the mark or label with the correct particular thereof specified for that seed under clause (b) of section 6.
Background of the case
The ministry of civil supply through an order dated 24.4.1983 had declared the seed for sowing or planting of food crops, fruits, vegetables, cattle fodder and jute to be essential commodities in exercise of power conferred by Section 2(a) (viii) of Essential Commodities Act, 1955. It was followed by the issue of seed (control) order dated 30th December 1983 by the Ministry of Agriculture, Dept. of Agriculture and Cooperation in exercise of powers contained in section 3 of Essential Commodities Act, which deals with Central Governments power to control, and regulate production, supply and distribution of essential commodities.
The seed (control) order 1983 had been notified as per Gazette notification G.S.R (832(E) dated 30.,12.1983. The notification under reference holds good and remains operative. Joint Secretary (Seeds), Government of India, Ministry of Agriculture, Department of Agriculture and Cooperation has been appointed as Seed Controller for implementation of seed (control) order.
Gist of the seed (Control) order 1983.
Issue of licence to dealers
All persons carrying on the business of selling, exporting and importing seeds will be required to carry on the business in accordance with terms and conditions of licence granted to him for which dealer make an application in duplicate in Form 'A' together with a fee of Rs.50/- for licence to licensing authority unless the State Government by notification exempts such class of dealers in such areas and subject to such conditions as may be specified in the notification.
Based on such enquiry as it thinks fit for licensing authority may grant in form 'B' or refuse in provisions of the Order. The refusal to grant licence shall be accompanied by clear recording of reasons for such refusal.
Renewal of licence
A holder of licence shall be eligible for renewal upon and applicable being made in the prescribed form 'C' (in duplicate) together with a feed of rupees twenty before the expiry of licence or at the most within a month of date of expiry of license for which additional fee of rS.25/- is required to be paid.
Appointing of licensing authority
The state government may appoint such number of persons as it thinks necessary to be inspector and define the area of such Inspector jurisdiction through notification in the official gazette.
Time limit for analysis of samples by Seed testing lab
Time limit for analysis of samples by seed testing lab and suspension / cancellation of license may be done by Licensing authority after giving an opportunity of being heard to the holder of license, suspend or cancel the license on grounds of mis-representation of a material particular or contravention in provision of the order.
Suspension / Cancellation of licence
The Licensing authority may after giving an opportunity of being head to the holder of licence, suspend or cancel the licence on grounds of mis-representation of material particular or contravention in provision of the Order.
Appeal
The state government may specify authority for hearing the appeals against suspension / cancellation under this order and the decision of such authority shall be final.
Any person aggrieved by an order of refusal to grant or amend or renew the licence for sale, export / import of seed may within 60 days from the date of Order appeal to the designated authority in the manner prescribed in the Order. Miscellaneous Plant variety protection and the Indian agriculture
The licencing authority may on receipt of request in writing together with Rs.10/- from amend the licence of such dealer.
Every seed dealer are expected to maintain such books, accounts and records to this business in order and submit monthly return of his business for the preceding months in Form 'D' to the licencing authority by 5th day of every month.
New seed policy
The Government of India evolved a new seed policy and which is implemented from October 1, 1988.
The policy laid a special emphasis on
- Import of high quality of seeds
- A time bound programme to modernize plant quarantine facilities
- Effective implementation of procedures for quarantine /post entry quarantine and
- Incentives to encourage the domestive industry
- Import of quality seeds.
1. Bulk import of seeds of coarse cereals, pulses and oil seeds may replace (or) displace the local productions.
2. Transfer of technology may not be actual one, because due to bulk import of seeds or import of technology, instead we can import the germplasm of superior variety if any and could be developed locally to meet the demand (i.e.,) incorporate the advantages of exotic variety to the local types(or) even direct multiplication's after adaptive trials.
3. As we have superior varieties of international standard (e.g.) Maize, Sorghum, Bajra, or even in oil seeds like groundnut etc., the bulk import is not necessitated. Instead we need varieties suitable to agroclimatic zones besides higher yields.
4. Import of flower seeds could be encouraged in order to earn foreign exchange through export of flours and it can be imported under (OGL) open general license. But there is a fear of introduction of new pest and diseases as they are coming without post entry quarantine checkup.
Strengthening of quarantine
Since, from 1st October 1988 only bulk import of seeds under taken without any progress either in the strengthening of quarantine facilities.
Threat of pest and disease
Introduction of new pest and disease would pose a new problem due to bulk import due to lack of post entry quarantine. To avoid this threat the imported seeds should be subjected to testing and it should be done by one person from ICAR. Entry of exotic variety without proper field testing may change the disease pattern if that particular strain is becoming susceptible to existing pathogens.
(e.g.) Karnal burnt - which was not noticed in the previous years and because a major disease on wheat after the introduction of Kalyansona.
Genetic erosion
It is another danger, due to introduction of similar strains there is a danger of genetic uniformity and also eliminates local diversified strains which leads to problem of non availability of improved strains if there is any out break of disease.
Incentives to domestic seed industry
Indigenous seed production / seed industry will be affected because of the entry of multi nation diseases. Since the policy is allowing indiscriminate bulk imports through private sectors at the same time the import duty on seeds has been reduced to 15 cent. Import duty on advanced machines and equipment used in seed production or processing has also been reduced and interest on post shiftement credit has also been slashed down to help importers.Income tax rebate and deduction are available to the tax paying units on the revenue expenditure on in house research and development. Incentives area also being provided to seed with located in backward areas and growth centres.
Seed testing
SEED SAMPLING
Seed sampling is to draw a portion of seed lot that represent the entire seed lot.
Introduction
Seed lot ‑ It is an uniformly blended quantity of seed either in bag or ‑in bulk.
Seed Size
Maximum quantity per lot
Larger than wheat and paddy
20,000 kg
Smaller than wheat and paddy
10,000 kg
Maize
40,000 kg
Sampling intensity
a. For seed lots in bags (or container of similar capacity that are uniform in size)
I. up to 5 containers Sample each container
but never, < 5 Primary sample
6-30 “ Sample atleast one in every 3 containers but never > than 5 P. S.
31-400 “ Sample atleast one in every 5 containers but never < 10 P. S.
401 or more Sample atleast one in every 7 containers but never < 80.
II. When the seed is in small containers such as tins, cartons or packets a 100 kg
weight is taken as the basic unit and small containers are combined to form sampling
units not exceeding this weight e.g. 20 containers of 5 kg each. For sampling purpose
each unit is regarded as one container.
b. For seeds in bulk
Up to‑500kg - Atleast 5 Primary sample
501 ‑ 3000 Kg - 1 Primary sample for each 300 kg but not less than 5
Primary sample
3001‑20,000 Kg - 1 Primary sample for each 500 kg but not less than 10
Primary sample
20,001 and above - 1 Primary sample for each 700 kg but not less than 40
Primary sample
PRINCIPLES OF SAMPLING
Sample is obtained from seed lot by taking small portion at random from different places and combining them. From this sample smaller samples are obtained by one or more stages. In each and every stage thorough mixing and dividing is necessary.
Methods of sampling
a. Hand sampling
This is followed for sampling the non free flowing seeds or chaffy and fuzzy seeds such as cotton, tomato, grass seeds etc., In this method it is very difficult to take samples from the deeper layers or bag. To over come this, bags are emptied completely or partly and then seed samples are taken. While removing the samples from the containers, care should be taken to close the fingers tightly so that no seeds escape.
b. Sampling with triers
By using appropriate triers, samples can be taken from bags or from bulk.
1. Bin samplers
Used for drawing samples from the lots stored in the bins.
2. Nobbe trier
The name was given after Fredrick Nobbe‑ father of seed testing. This trier is made in different dimensions to suit various kinds of seeds. It has a pointed tube long enough to reach the centre of the bag with an oval slot near the pointed end. The length is very small. This is suitable for sampling seeds in bag not in bulk.
3. Sleeve type triers or stick triers
It is the most commonly used trier for sampling : There are two types viz.,
1. With compartments 2. Without compartments.
It consists of a hollow brass tube inside with a closely fitting outer sleeve or jacket which has a solid pointed end. Both the inner tube as well as the outer tube have been provided with openings or slots on their walls. When the inner tube is turned, the slots in the tube and the sleeve are in line. The inner tube may or may not have partitions.
This trier may be used horizontally or vertically. This is diagonally inserted at an angle of 300C in the closed position till it reaches the centre of the bag. Then the slots are opened by giving a half turn in clockwise direction and gently agitated with inward push and jerk, so that the seeds will fill each compartment through the openings from different layers of the bag, then it is again closed and with drawn and emptied in a plastic bucket. This trier is used for drawing seed samples from the seed lots packed in bags or in containers.
TYPES OF SAMPLES
1. Primary sample
Each probe or handful of sample taken either in bag or in bulk is called primary sample.
2.Composite sample
All the primary samples drawn are combined together in suitable container to form a composite sample
3. Submitted sample
When the composite sample is properly reduced to the required size that to be submitted to the seed testing lab, it is called submitted sample. Submitted sample of requisite weight or more is obtained by repeated halving or by abstracting and subsequently combining small random portions.
4. Working sample
It is the reduced sample required weight obtained from the submitted sample on which the quantity tests are conducted in seed testing lab.
Weight of submitted sample
The minimum weight for submitted samples for various tests are as follows
1.Moisture test
100 gm for those species that have to be ground and 50 gm for all other species. 2.For verification of species and cultivar
2. For verification of species and cultivars
Crop
Lab only (g)
Field plot
& Lab (g)
Peas, beans, maize, soybean and crop seeds of similar
1000
2000
Size
500
1000
Barley, oats, wheat and crop seeds of similar size
200
500
Beet root and seeds of similar size
100
250
All other genera
3. For other tests like uri and count of other species
Crop
Size of
seed lot
(kg)
Size of
submitted
sample
Size of working
purity
Sample
count of other
species
Paddy
25,000
400
40
400
Wheat
25,000
1000
120
1000
Maize
40,000
1000
900
1000
Sorghum
10,000
900
90
900
Bajra
10,000
150
15
150
Red gram
20,000
1000
300 .
1000
Green gram
20,000
1000
120
1000
Black gram
20,000
1000
150
1000
Bengal gram
20,000
1000
1000
1000
Cowpea
20,000
1000
400
1000
Soybean
20,000
1000
500
1000
Groundnut (pods)
20,000
1000
1000
1000
Groundnut (kernels)
20,000
1000
600
1000
Gingelly
10,000
70
7
70
Sunflower (variety)
20,000
1000
250
1000
Sunflower (hybrid)
20,000
1000
125
250
Cotton linted (variety)
20,000
1000
350
1000
Cotton de-Tinted
20,000
350
35
350
(variety)
20,000
350
35
350
Cotton linted (hybrid)
20,000
250
25
250
Cotton de-Tinted
10,000
150
15
150
(hybrid)
10,000
150
15
150
Brinjal
20,000
1000
140
1000
Chillies
10,000
70
7
70
Bhendi
10,000
7
7
7
Tomato (variety)
10,000
100
10
100
Tomato (hybrid)
10,000
100
10
100
Cabbage
10,000
100
10
100
Cauliflower
Knolkhol
The samples taken may packed in bags, sealed and marked for identification. For moisture testing the samples should be packed separately in moisture proof polythene bag and kept in the container along with the submitted samples.
Information to accompany the sample
Date Kind Variety
Class of seed Lot No.
Quantity of seed in lot (kg)
Tests) required (1) Purity (2) Germination (3) Moisture
Senders Name and Address
Types of sample used in Seed Testing Laboratory
Service sample - Sample received from the farmers
Certified sample - Sample received from certification agencies or officers
Official sample - Sample received from the seed inspectors.
Mixing and dividing of seeds
The main objective of mixing and dividing of seeds is to obtain the representative homogenous seed sample for analysis by reducing the submitted sample to the desired size of working sample.
Method of mixing and dividing
1. Mechanical dividing
2. Random cups method
3. Modified halving method
4. Spoon method
5. Hand halving method
1. Mechanical method
The reduction of sample size is carried out by the mechanical dividers suitable for all seeds except for chaffy and fuzzy seeds.
Objective of mechanical dividing
· To mix the seed sample and make homogenous as far as possible
· To reduce the seed sample to the required size without any bias
· The submitted sample can be thoroughly mixed by passing it through the divider to get 2 parts and passing the whole sample second time and 3rd time if necessary to make the seeds mixed and blended so as to get homogenous seed sample when the same seeds passed through it into approximately equal parts.
· The sample is reduced to desired size by passing the seeds through the dividers repeatedly with one half remain at each occasion.
TYPES OF MECHANICAL DIVIDERS
1. Boerner divider
It consists of a hopper, a cone and series of baffles directing the seeds into 2 spouts. The baffles are of equal size and equally spaced and every alternate one leading to one spout. They are arranged in circle and are directed inward. A valve at the base of the hopper retains the seeds in the hopper. When the valve is opened the seeds fall by gravity over the cone where it is equally distributed and approximately equal quantity of seeds will be collected in each spout. A disadvantage of this divider is that it is difficult to check for cleanliness.
2. Soil divider
It is a sample divider built on the same principles as the Boerner divider. Here the channels are arranged in a straight row. It consists of a hopper with attached channels, a frame work to hold the hopper, two receiving pans and a pouring pan. It is suitable for large seeds and chaffy seeds.
3. Centrifugal or Gamet Divider
The principle involved is the centrifugal force which is used for mixing and dividing the seeds. The seeds fall on a shallow rubber spinner which on rotation by an electric motor, throw out the seeds by centrifugal force. The circle or the area where the seeds fall is equally divided into two parts by a stationary baffle so that approximately equal quantities of seed will fall in each spout.
II. RANDOM CUP METHOD
This is the method is suitable for seeds requiring working sample upto 10 grams provided that they are not extremely chaffy and do not bounce or roll (e.g.) Brassica spp.
Six to eight small cups are placed at random on a tray. After a preliminary mixing the seed is poured uniformly over the tray. The seeds that fall into the cup is taken as the working sample.
III. MODIFIED HALVING METHOD
The apparatus consists of a tray into which is fitted a grid of equal sized cubical cups open at the top and every alternate are having no bottom. After preliminary mixing the seed is pouted evenly over the grid. When the grid is lifted approximately half the sample remains on the tray. The submitted sample is successively halved in this method until a working sample size is obtained.
IV. SPOON METHOD
This is suitable for samples of single small seeded species. A tray, spatula and a spoon with a straight edge are required. After preliminary mixing the seed is poured evenly over the tray. The tray should not be shacked there after. With the spoon in one hand, the spatula in the other and using both small portions of seed from not less than 5 random places on the tray should be removed. Sufficient portions of seed are taken to estimate a working sample of approximately but not less than the required size.
V. HAND HALVING METHOD
This method is restricted to the chaffy seeds. The seed is poured evenly on to a smooth clean surface and thoroughly mixed into a mound. The mound is then divided into 1/2 and each half is mound again and halved to 4 portions. Each of the 4 portions is halved again giving 8 portions. The halved portions are arranged in rows and alternate portions are combined and retained. The process is repeated until the sample of required weight is obtained.
SEED PURITY ANALYSIS
The purity test is the first test to be made. Seed samples can contain impurities such as weed seeds, seeds of other crop species, detached seed structures, leaf particles and other material. The object of purity analysis is to determine the composition of the sample being tested by weight. To do this, a purity test is conducted, in which the working sample is separated into the following component parts:
i) Pure seed refers to the species under consideration. In addition to mature, undamaged seed, it includes, undersized, shriveled, immature and germinated seeds, provided they can be definitely identified as the species under consideration, more over it includes pieces resulting from breakage that are more than one half their original size Pure seeds includes the following:
A. Intact seeds
B. Achenes and similar fruits like caryopsis, schizocarpand mericarp with or without pedicel, perianth and whether they contain true seed unless it is apparent and when difficult to identify.
C. Pieces of seeds, achenes, mericarp and caryopsis resulting from breakage that is more than half the original size (Half seed rule). However, seeds of Leguminosae, Cruciferae and Coniferae are considered as inert matter if their seed coat is removed.
D. Clusters of Beta or pieces of such clusters with or without seeds that are retained by 200 x 300 mm sieve.
E. Florets and caryopsis of Grammae.
* florests and one flowered spikelets with an obvious caryopsis containing endosperm provided also that the caryopsis of particular genera and species have attained minimum sizes.
* Free caryopsis
* All florets and caryopsis (except broken florets and caryopsis half or less than half the original size and in the case of Dactylis glomerata excluding one-fifth of the weight of multiple floret in which the sterile floret extends to or beyond the tip of the fertile floret) remaining in heavy protein after blowing at an uniform blowing speed.
With reference to specific species:
Allium sp., Capsicum sp., Cucumis sp., Lycopsersicon sp., : Seed with or without seed except pieces of seed more than 1/2 the original size with or without seed coat.
Arachis sp., Cicer sp., Glycine sp., Vigna sp. : Seed, provided a portion of testa is attached, pieces of seed more than 1/2 the original size with or without seed coat.
Daccus sp. : Schizocarp with or without pedicel unless it is obvious that no seed is present Mericarp with or without pedicel unless it is obvious that no seed is present. Pieces of mericarp more than 1/2 the original size unless it is apparent that no seed is present. Seed with pericarp partially or entirely removed. Pieces of seed larger than 1/2 the original size with the pericarp partially or entirely remove.
Gossypium sp.: Seed with or without lint, pieces of seed more than 1/2 the original size.
Helianthus sp. : Achene unless it is obvious that no seed is present. Pieces of achene larger than 1/2 the original size unless it is obvious no seed is present. Seed with the pericarp partially or entirely removed. Pieces of seed large than 1/2 the original size partially or entirely removed.
Oryza sp. : Spilelet with lemma, palea and sterile glumes enclosing a caryposis. Floret with lemma palea enclosing a cryopsis. Free caryopsis.
ii) Other seeds shall include seeds and seed like structures of any plant species other than that of pure seed. iii) Inert matter includes seed units and all other matters and structures not defined as pure seed or other seed. It includes, seeds and seed like structures eg., achenes , caryopsis , mericarp and seeds of leguminosae less than ½ the original size with no seed coat.
To perform purity analysis, the working sample is kept over the purity work board at the base end. A small quantity of sample is brought to the middle of the board and split into two basic components as pure seed and inert matter. The inert matter is further divided as pieces of seeds less than 1/2 the original size, stones, pieces of leaves, weed seeds, other crop seed etc. The pure seed is further divided into pure seed and other distinct variety (ODV) etc. The pure seed and inert matter are weighed upto three decimals and percentage worked out. The weed seed, OCS, ODV are counted and reported as number per kg.
Instruments
1. Seed blower
It is used to remove the light weighted inert matter from the seeds. Working sample is kept at the lower portion of the tube and the required uniform upward flow of air is regulated upto prescribed period of time. Lighter matter is separated from the sample by air flow and settle down in the partition provided in the tube of the blower. The tube is removed and inert matter is collected.
2. Diapanascope
The purity work board is provided with light source in the background which facilitates easy separation of different component. It also helps better distinguishing of red pericarp from white percarb and short bold grains long slender grains from medium types.
The percentage by weight of each of the component parts shall be calculated to one decimal place. Percentage must be based on the sum of the weight of the components not on the original weight of the working sample, but the sum of the weights of the components must be compared with the original weight as a check against loss of material or other error. The result shall be reported to one decimal place and the percentage of all components must total 100. Components of less than 0.05% shall be reported as Trace. If the purity is less than the standard retirement the certification department will reject the seed.
Seed Moisture Estimation
The moisture content of a sample is the loss in weight when it is dried in accordance with the rules. It is expressed as a percentage of the weight of the original sample. The submitted sample shall be accepted for moisture determination only if it is in intact, moisture - proof container from which as much air as possible has been excluded. The determination shall be started as soon as possible after receipt.
Procedures
Weighing shall be in grams to three decimal places. Seeds of larger size are ground before drying unless its high oil content makes it difficult. After grinding, the sample is passed through different sizes of sieves. Pre-drying before grinding is required for samples having moisture content more than 17%. After pre-drying, the sub-damples are reweighed in their containers to determine the loss in weight.
I. Low constant temperature oven method
The working sample must be evenly distributed over the surface of the container. Weigh the container and its cover before and after filling. Place the container rapidly, on top of its cover, in an oven maintained at a temperature of 103 ± 2°C and dry for 17 ± 1 hours. The drying period begins at the time the oven returns to the required temperature. At the end of the prescribed period, cover the container and place it in a desiccator to cool for 30-40 minutes. After cooling, weigh the container with its cover and contents. The relative humidity of the ambient air in the laboratory must be less than 70% at the time of final weighing. ISTA prescribes the low constant temperature oven method, for all tree species. Normally oilseeds are subjected to low constant temperature oven method while cereals and pulses are subjected to high constant temperature oven method.
II. High constant temperature oven method
The procedure is the same as above except that the oven is maintained at a temperature of 130-133°C, the sample is dried for a period of four hours for tree species and no special requirement pertains to the relative humidity of the ambient air in the laboratory during determination.
The moisture content as a percentage by weight shall be calculated to one decimal place by means of the following formula:
100
(M2-M3) x ----------
M2 - M1
Where
M1 - is the weight in grams of the container and its cover,
M2 - is the weight in grams of the container, its cover and its contents before drying and
M3 - is the weight in grams of the container, cover and contents after drying.
If the material is pre-dried, the moisture content is calculated form the results obtained in the first (pre-dried), the second stages of the procedure. If S1 is the moisture lost in the first stage, and S2 is the moisture lost in the second stage, each calculated as above and expressed as a percentage, then the original moisture content of the sample calculated as a percentage is
S1 x S2
S1 + S2 - -----------
100
Grinding requirements
Crop
Grinding
Mesh size
Paddy, wheat, maize, sorghum, cotton
Fine
50% ground material is passed through 0.5 mm mesh
10% ground material remain on 1.00 mm mesh
Pea, chickpea, soybean, lathyrus
Coarse
50% ground material is passed through 4 mm mesh
Pre-drying requirements
Crop
Moisture content
Temperature required for drying °C
Duration
Maize
>25%
>0
2 - 5 hrs
Rice
>13%
130
5 - 10 min
Soybean
>10%
130
5 - 10 min
III. Universal moisture meter
Moisture estimation is made quick by the advent of digital moisture meters. The principle involved is that electrical conductivity of moist material is directly proportionate to the amount of moisture content in it.
Universal moisture meter is a popular and most dependable instrument for moisture estimation. The following are its essential parts:
(i) Compression unit (ii) Moisture meter dial
(iii) Thermometer (iv) Compression knob
(v) Cups of different volumes
A representative sample of prescribed weight or volume (Table ) is obtained and placed in the sample cup. It is fixed in the lower house of compression unit.
Meter is calibrated by pressing the button "CAL" and "BELL" with the help of calibration knob. Sample is compressed as per requirement with the help of compression knob and scale. At required compression the meter dial (M) is read by pressing the knob "Read" and bell. Temperature (T) is observed by the thermometer fixed in between meter dial and compression chamber. The reading M and T are intercepted on the corelator dial (moisture meter dial) by turning the temperature dial. On adjustment of both the reading mark of arrow on the outer reading of temperature dial indicates the moisture percentage. For some crops factor is also considered for estimation of moisture content (Table ).
Determination of moisture content by universal moisture meter
Crop
Sample size
Compression
Factor
Weight (g)
Volume*
FIELD AND FODDER CROPS
Barley
50
B
0.600
Maize
60
B
0.560
Oat
30
B
0.400
Pearl millet
60
B
0.500
Rice
50
B
0.550
Sorghum
50
B
0.675
Wheat
30
A
0.275
Add 1%
Moong and urid
A
0.275
Add 1.5%
Chickpea
C
0.500
Subtrat 1%
Horsegram
A
0.275
Lentil
A
0.250
x 0.7 + 3.5%
Pigeonpea, fieldpea
C
0.450
Castor
C
0.500
Multiplied by 0.5
Groundnut
25
0.300
Multiplied by 0.6
Groundnut (kernel)
26
0.450
Multiplied by 0.56
Safflower
15
0.450
Multiplied by 0.66
Sesame
0.550
Subtract 0.5%
Soybean
60
C
0.575
Subtract 2.5%
Sunflower
30
B
0.500
Multiplied by 0.6
Rape seed and mustard
0.450
Multiplied by 0.6
Cotton (linted)
30
C
0.360
Subtract 5%
VEGETABLES
Kidneybean
50
B
0.400
Okra
C
0.425
Cabbage
A
0.260
Multiplied by 0.6
Cowpea
A
0.325
Multiplied by 0.8
Cucumber
B
0.525
Multiplied by 0.8
Lettuce
B
0.500
Multiplied by 0.9
Onion
A
0.250
Subtract 2.5%
Tomato
25
B
0.250
Multiplied by 0.8
Turnip
25
0.200
Multiplied 0.8
Watermelon
B
0.425
Subtract 3.5%
Coriander
C
0.325
Multiplied by 0.6
* A,B and C - Container size
The moisture content must be reported to the nearest 0.1% in the space provided on the Analysis Certificate. Seed lot with moisture content more than the minimum seed certification standards (Table ) are recommended for drying
Minimum seed certification standard for moisture percentage
Crop
Sample in vapour proof container
Sample not in vapour proof bag
FIELD AND FODDER CROPS
Castor, mustard, taramira
5
8
Groundnut, niger, sesame
5
9
Cotton
6
10
Rape seed
7
8
Linseed, horsegram, rajmash, safflower, sunflower, jute
7
9
Berseem, lucerne, Indian clover
7
10
Soybean
7
12
Moong, urid, chickpea, fieldpea, pigeonpea, lentil, lathyrus, kidneybean, ricebean
8
9
Buffel, Dharaf, Dinanath, guinea, marvel, setaria and stylo grass
8
10
Wheat, maize, sorghum, pearl millet, barley, triticale, oat, minor millets, teosinte, forage sorghum
8
12
Rice
8
13
VEGETABLES
Rat tail radish, radish, turnip
5
6
Cole crops
5
7
All cucurbits
6
7
TPS, brinjal, tomato, chilli, capsicum, onion, fenugreek, lettuce, amaranth, asparagus
6
8
Carrot, celery, parsley
7
8
French bean
7
9
Cowpea, Indian bean, clusterbean, spinach, sugarbeat
8
9
Okra
8
10
SEED GERMINATION TEST
Principles
Germination tests shall be conducted with a pure seed fraction. A minimum of 400 seeds are required in four replicates of 100 seeds each or 8 replicates of 50 seeds each or 16 replicates of 25 seeds each depending on the size of seed and size of containers of substrate. The test is conducted under favourable conditions of moisture, temperature, suitable substratum and light if necessary. No pretreatment to the seed is given except for those recommended by ISTA.
Materails required
A. Substratum
The substratum, serves as moisture reservoir and provides a surface or medium for which the seeds can germinate and the seedlings grow.The commonly used substrata are sand, paper and soil.
I. Sand
a. Size of sand particle
Sand particles should not be too large or too small. The sand particles should pass thorough 0.80 mm sieve and retained by 0.05 mm sieve.
b. Toxicity
Sand should not have any toxic material or any pathogen. If there is presence of any pathogen, found, then the sand should be sterilized in an autoclave.
c. Germination Tray
When we use the sand, germination trays are used to carry out the test. The normal size of the tray is 22.5 x 22.5 x 4 cm. They tray may either zinc or stainless steel.
B. Method of seed placement
1. Seeds in sand(s)
Seeds are planted in a uniform layer of moist sand and then covered to a depth of 1 cm to 2 cm with sand.
2. Top of sand (TS)
Seeds are pressed into the surface of the sand
C. Spacing
We must give equal spacing on all sides of facilitate normal growth of seedling and to avoid entangling of seed and spread of disease. Spacing should be 1‑5 times the width or diameter of the seed.
D. Water
The amount of water to be added to the sand will depend on size of the seed. For cereals, except maize, the sand can be moistened to 50% of its water holding capacity. For large seeded legumes and maize sand is moistened to 60% water holding capacity.
II. Paper
Most widely used paper substrates are filter paper, blotter or towel (kraft paper). It should be have capillary movement of water, at vertical direction (30 mm rise / min.). It should be free from toxic substances and free from fungi or bacteria. It should \ hold sufficient moisture during the period of test. The texture should be such that the roots of germinating seedlings will grow on and not into the paper.
A. Methods
a. Top of Paper (TP)
Seeds are placed on one or more layers of moist filter paper or blotter paper in petridishes. These petridishes are covered with lid and placed inside the germination cabinet. This is suitable of those seeds which require light.
a. Between paper (PP)
The seeds are placed between two layers of paper
b. Roll towel method
The seeds are placed between two layers of paper and rolled in towels. The rolled towels are placed in a water source and kept in germinator or germination room
c. Inclined plate method
Germination on glass plate with germination paper and kept at an angle of 45 0
III. SOIL
Should be non-caking, free from large particles. It must free from weed seeds, bacteria, fungi, nematode and other toxic substances. Soil is not recommended for reuse.
B. TEMPERATURE
Normally most of the seeds germinat between 20-300 C
C. LIGHT
Light required seeds provided with light eg. Lettuce
GERMINATION REQUIREMENTS FOR DIFFERENT CROPS
Crop
Substratum
Temp 0 C
First count
( Days)
Final count
(days)
Pre - treatment
PAddy
BP,TP,S
20-30
5
14
Pre heat (500 C) soak in water for 24 hours
MAize
BP,S
20-30
4
7
-
Bajra
TP,BP
20-30
3
7
0.2% KNO3 92-3 hrs) /prechill
Sorghum
TP,BP
20-30
4
10
-
Redgram
BP
20-30
4
6
-
Blackgram
BP
30
4
7
-
Greengram
BP
20-30
5
8
-
Bengalgram
BP
20-30
5
8
-
Cowpea
BP
20-30
5
8
--
Peas
BP
20
5
8
-
Castor
BP
20
7
14
-
Groundnut
BP
20-30
5
10
-
Sunflower
BP
20-30
4
10
-
Sesame
TP
20-30
3
6
-
Cotton
BP,S
20-30
4
12
Reithove shells
Brinjal
TP,BP
20-30
7
14
EthreI (25 ppm) 48 hrs.
Tomato
TP,BP
20-30
5
14
Chillies
TP,BP
20-30
7
14
(Hot water 85° C 1 min)
Bhendi
BP,S
20-30
4
21
Onion
TP,BP
15-20
6
21
KN03
Carrot
TP,BP
20-30
7
14
KN03
Radish
TP,BP
20-30
4
10
Prechill
Cabbage
prechill
Cauliflower
TP
20-30
5
10
Prechill, KN03
Ash gourd
S
30-35
5
14
light
Biter gourd
BP,S
20-30
4
14
Bottle gourd
BP,S '
20-30
4
14
-
GERMINATION APPARATUS
1. Germination Cabinet / Germination
This is called chamber where in temperature and relative humidity are controlled. We can maintain the required temperature
2. Room germinator
It works with same principle of germinator. This is a modified chamber of larger one and the worker can enter into it and evaluate the seedlings. Provisions are made to maintain the temperature and relative humidity. This is used widely in practice.
3. Counting Board
This is used for accurate counting and spacing of seeds. This consists of 2 plates. The basal one is stationary and top one is movable. Both top and basal plates are having uniform number of holes viz., 50/100, when the plates are in different position. After taking the sample, the top plate is pulled in such a way that the holes are in one line so that the fixed number of seeds fall on the substratum.
4. Vacuum Counter
Consists of a head, pipe and wall. There are plates of 50 or 100 holes which can be fitted to the head. When vacuum is created the plate absorbs seeds and once the vacuum is released the seeds fall on the substrate.
5. Impression Board
Made of plastic / wood with 50 or 100 holes/pins. Here the knobs are arranged in equal length and space. By giving impression on the sand it makes uniform depth and spacing for seed.
D. Seedling Evaluation
ISTA classified the seedlings into different categories based on the development of essential structures
CATEGORIES OF SEEDLINGS
1. Normal seedlings
2. Abnormal seedlings
3. Hard seeds
4. Fresh ungerminated seeds
5. Dead seeds
1.Normal seedlings
Seedlings which show the capacity for continued development into normal plant when grown in favorable conditions of soil, water and temperature.
Characters of normal seedling
1. A well developed root system with primary root except in certain species of graminae which normally producing seminal root or secondary root
2. A well developed shoot axis consists of elongated hypocotyls in seedlings of epigeal germination.
3. A well developed epicotyl s in seedlings of hypogeal germination.
4. One cotyledons in monocots and two in dicots
5. A well developed coleoptile in graminae containing a green leaf
6. A well developed plumule in dicots
7. Seedlings with following slight defects are also taken as normal seedlings. Primary root with limited damage but well developed seminal root system in leguminosae (Pisum), graminae (maize), cucurbitaceae (cucumis) and malvaceae(cotton)
8. Seedlings with limited damage or decay to essential structures but no damage to conducting tissue
9. Seedlings which are decayed by pathogen but it is clearly evident that the parent seed is not the source of infection.
II. Abnormal Seedlings
Seedlings which do not show the capacity for continued development into normal plant when grown in favorable conditions of soil, water and temperature
Types of abnormal seedling
A. Damaged seedlings
Seedlings with any one of the essential structures missing or badly damaged
so that the balanced growth is not expected. Seedlings with no cotyledons, with splits, cracks and lesions or essential structures and without primary root.
B. Deformed seedlings
Weak or unbalanced development of essential structures such as spirally twisted or stunted plumule or hypocotyls or epicoptyl, swollen shoot, stunted roots etc.
C. Decayed seedlings
Seedlings with any one of the essential structures showing diseased or decayed symptoms as a result of primary infection from the seed which prevents the development of the seedlings.
III.Hard seeds
Seeds which do not absorb moisture till the end of the test period and remain hard (e.g.) seeds of leguminosae and malvaceae
IV.Fresh ungerminated seeds
Seeds which are neither hard nor have germinated but remain firm and apparently viable at the end of the test period.
V. Dead seeds
Seeds at the end of the test period are neither hard nor fresh'or have produced any part of a seedling. Often dead seeds collapse and milky paste comes out when pressed at the end of the test.
Retesting
If the results of a test are considered unsatisfactory it shall not be reported and a second test shall be made by the same method or by alternative method under the following circumstances.
1. Replicates performance is out of tolerance
2. Results being inaccurate due to wrong evaluating of seedlings or counting or errors in test conditions.
3. Dormancy persistence or phytotoxicity or spread of fungi or bacteria. The average of the two tests shall be reported.
Use of tolerances
The result of a germination test can be relied upon only if the difference between the highest and the lowest replicates is within accepted tolerances.
To decide if two test results of the same sample are compatible again the tolerance table is used.
Reporting results
The results of the germination test is calculated as the average of 4 x 100 seed replicates.It is expressed as percentage by number of normal seedlings.The percentage is calculated to the nearest whole number. The percentage of abnormal seedlings, hard, fresh and dead seeds is calculated in the same way. These should be entered on the analysis of certificate under appropriate space.If the result is nil for any of these categories it shall be reported as '0'.
Seed standards for germination
S.No.
Crop
Class of seed
Foundation Seed
Certified seed
1
Paddy
80
80
2
Maize (inbreds)
80
-
Single cross
80
80
Double cross
-
90
Variety
90
90
3
Sorghum (variety)
75
75
Hybrids
75
75
4
Cumbu
75
75
5
Ragi
75
75
6
Black gram
75
75
7
Bengal gram
85
85
8
Green gram
75
75
9
Horse gram
80
80
10
Peas
75
75
11
Pigeon pea
75
75
12
Castor variety
70
` 70
13
Ground nut
70
70
14
Sesame
80
80
15
Soybean
70
70
16
Sunflower
70
70
17
Cotton
65
65
18
Jute
80
80
19
Gourds
60
60
20
Brinjal
70
70
21
Chillies
60
60
22
Bhendi
65
65
23
Tomato
70
70
24
Cabbage
70
70
25
Cauliflower
65
65
26
Carrot
60
60
27
Radish
70
70
28
Beet root
60
60
QUICK VIBILITY TEST
The relative long periods of time required for completion of germination tests delays the seed marketing. This necessitated the development of rapid methods for estimating the germination capacity of seeds. This test was developed by Lakon (1942) in Germany.
Principle
It is a biochemical test, in which living cells are made visible by reduction of an indicator dye. The indicator used is 2,3,5 triphenyl tetrazolium chloride. Within the seed tissues, it interferes with the reduction processes of living cells and accepts hydrogen from the hydrogenases. By hydrogenation of the 2,35 ‑ tri phenyl tetrazolium chloride; a red stable and non difficusable substance, triphenyl formazan is produced in living cells. The reaction is as follows.
N-N ‑C6H5 N‑NH ‑C6H5
C6 H5 –C +2e+2H+ C6H5 ‑ C+ ~ + H+ Cf
N=N+ C61‑15 N=N‑ CA
Cl'
2,3,5 triphenyl tetra zolium chloride Triphenyl formazon
This makes it possible to distinguish red coloured living parts of seeds from the colourless dead ones. Staining of seeds determines whether seeds are to be classified as viable. Completely stained seeds are viable partially and completely unstained seeds are non‑viable
Field of application
This test is not valid for previously germinated seeds
Method of Tetrazolium testing
A. Testing sample
A representative sample of 50(or) 100 seeds is usually sufficient. l lowever, 200 seeds, in replicates of 100 seeds is recommended.
B. Preparation of solutions
1% solution is used for seeds that are not bisected thro' the embryo, while 0.1% solution is used for seeds in which the embryo is bisected.
The pH of the solution should be between 6 and 8 for best staining. If the pH of the water is not in the natural range, the TZ salt should be dissolved in a phosphate buffer solution. The buffer solution is prepared as follows
Solution ‑1‑ Dissolve 9.078 g of KH2 P04 in 1000 ml of water
Solution ‑2‑ Dissolve 11.876 g of Na2HP04. 2H20 in 1000 ml water.
Take 400 ml of solution 1 and 600 ml of solution 2 and mix them together. In litre of buffer solution prepared as above, dissolve 10 gms of TZ salt. This gives 1% TZ solution of pH 7.0. This may be further diluted to give lower concentrations. The solution should be stored in brown bottle to prevent deterioration from light.
Methods of preparation for tetrazolium testing
The seeds are first prepared for staining then stained and evaluated for viability.
Method 1 : Bisect longitudinally
(e.g) maize, sorghum, small grains, large seeded grasses. Soak the seeds in water for 3 to 4 hours. Bisect the seeds by cutting longitudinally thus exposing the mains structures of the embryo. Use one 1/2 of each seed for testing.
Method 2 : Bisect laterally
(e.g.) Small seeded grasses
The seeds are cut laterally near the centre of the seed above the embryo. Place embryo end in TZ solution.
Method 3 : Pierce with needle
(e.g.) Small seeded grasses
Puncture the seeds by piercing thro' the seed into the endosperm near the embryo, but avoid injury to the embryo.
Method 4 : Remove seed coat (e.g) seeds with seed coats impermeable to tetrazolium.
Soak the seeds in water for 3‑4 hours and then the seed coats and place the seeds in the TZ solution. In some crops like cotton a thin membrane adhering .to the cotyledons is also removed in addition to the seed coat.
Method 5 : Conditioning only
(e.g) Large seeded legumes
Seeds of soybeans and other large seeded legumes may swell so rapidly and irregularly when placed directly in water or TZ solution that the seed coats burst. Hence, it is preferable to condition these seeds slowly in moist paper towels overnight before staining, so that they absorb moisture slowly without any damage to the seed.
but avoid injury to the embryo.
Method 4 : Remove seed coat
(e.g) Dicots with seed coats impermeable to tetrazolium.
Soak the seeds in water for 3‑4 hours and then the seed coats and place the seeds in the TZ solution. In some crops like cotton a thin membrane adhering .to the cotyledons is also removed in addition to the seed coat.
Method 5 : Conditioning only
(e.g) Large seeded legumes
Seeds of soybeans and other large seeded legumes may swell so rapidly and irregularly when placed directly in water or TZ solution that the seed coats burst. Hence, it is preferable to condition these seeds slowly in moist paper towels overnight before staining, so that they absorb moisture slowly without any damage to the seed.
Method 5 : Conditioning only
(e.g) Large seeded legumes
Seeds of soybeans and other large seeded legumes may swell so rapidly and irregularly when placed directly in water or TZ solution that the seed coats burst. Hence, it is preferable to condition these seeds slowly in moist paper towels overnight before staining, so that they absorb moisture slowly without any damage to the seed.
METHOD 6 : NO CONDITIONING OR PREPARATION
(eg.) Small seeded legumes
Seed coats of these seeds are permeable to TZ and embryos usually will stain without conditioning.
Staining
The prepared seeds should be placed in suitable container (small beakers, petridishes
etc.,) and covered with TZ solution. Place the containers in an incubator at dark warm conditions of 40°C.The staining time varies for different kinds of seeds, different kinds of seeds, different methods of preparation, and different temperatures (< 1 hr to 8 hrs).
When the sample has stained sufficiently the TZ solution should be discarded and the
seed sample covered with water immediately. Seed samples can also be kept for 3 days at 10°C for interpretation.
Evaluation of Samples : A normal TZ stain appears cherry red.
MONCOTS
Non‑Viable
1. All structures unstained
2. Shoot largely unstained
3. Scutellar node unstained
4. Major areas of coloeptile unstained
5. Central area of scutellum unstained
6. Insect, mechanical or other injuries causing essential structures non functional.
DICOT SEEDS
Non‑viable
1. Embryo completely unstained
2. More than extreme tip of radical unstained
3. More than 1/2 of cotyledon tissue unstained.
4. Deep ‑ seated necrosis at cotyledon and embryonic axis juncture or on radicle
5. Fractured radical.
Advantages of TZ test
I.Quick estimation of viability
2.When the seed is dormant, the TZ test is extremely useful
3. Seeds are not damaged (in dicot) in anlaysis therefore they could be germinated.
Disadvantages of TZ Test
1. It is difficult to distinguish between normal and abnormal seedlings.
2. It does not differentiate between dormant and non‑ dormant seeds.
3. Since the TZ test does not involve micro organisms harmful to germinating seedlings are not detected.
SEED STORAGE
What is seed storage - preservation of seed wioth initial quality until it is needed for planting.
Introduction
The ability of seed to tolerate moisture loss allows the seed to maintain the viability in dry state. Storage starts in the mother plant itself when it attains physiological maturity. After harvesting the seeds are either stored in ware houses or in transit or in retail shops. During the old age days , the farmers were used farm saved seeds, in little quantity, but introduction of high yielding varieties and hybrids and modernization of agriculture necessitated the development of storage techniques to preserve the seeds.
The practice of storing the seeds starts from the ancient days itself, following simple and cheap techniques eg. Placing the seeds ins alt, red earth treatment to red gram etc. But the same practices are not hold good for the present day agriculture, because
- large quantity to be stored
- exchange of varieties and species
- exchange of genes
The type of material to be stored decides the techniques to be followed for safe storage. Now a days storage technique changed from ordinary go-down storage to cryogenic tank storage and even gene storage.
Objective of seed storage :
To maintain initial seed quality viz., germination, physical purity, vigour etc., all along the storage period by providing suitable or even better conditions.
Factors influencing seed storage
Biotic
A biotic
Biotic factors :
a. Factors related to seed
- Genetic make up of seed
- Initial seed quality
- Provenance
- Seed Moisture content
b. Other biotics
- Insects
- Fungi
- Rodents
- Mishandling during sampling, testing
2. Abiotic factors
- Temperature
- Relative humidity
- Seed store sanitation
- Gaseous atmosphere
- Packaging material
Seed factors :
1.Genetic factors
The storage is influenced by the genetic make up of the seed. Some kinds are naturally short lived (e.g) onion, soybeans, ground nut etc., Based on the genetic make up seeds are classified into
Micro biotic – short lived
Meso biotic- medium lived
Macro biotic – long lived
Initial seed quality
Barton (1941) found that the seeds of high initial viability are much more resistant to unfavourable storage environmental conditions than low viable seed. Once seed start to deteriorate it proceeds rapidly. The seed which injured mechanically suffered a lot and loses its viability and vigour very quickly. Generally small seeds escape injury whereas large seeds are more likely to be extensively damaged (e.g) bean, lima-bean and soybean. Spherical seeds usually give more protection than flat or irregularly shaped seeds
Effect of provenance : The place where the seed crop was produced greately influences the storability.
(e.g.) Red clover seeds grown in Canada stored for 4 years with 80% germination whereas seeds grown in England and Newzealand stored only for 3 years with 80% germination. This is due to different climatic conditions and soil types prevailing in different places.
Effect of weather
Fluctuating temperature during seed formation and maturity will affect seed storage. Pre-harvest rain may also affect the viability.
Pre harvest sanitation spray
In pulses, insect infestation comes from field (e.g.) bruchids.
Seed moisture content
Most important factor influence the storability. The amount of moisture in the seeds is the most important factor influencing seed viability during storage.
Generally if the seed moisture content increases storage life decreases. If seeds are kept at high moisture content the losses could be very rapid due to mould growth very low moisture content below 4% may also damage seeds due to extreme desiccation or cause hard seededness in some crops.
Since the life of a seed largely revolves around its moisture content it is necessary to dry seeds to safe moisture contents. The sage moisture content however depends upon storage length, type of storage structure, kind / variety of seed type of packing material used. For cereals in ordinary storage conditions for 12-18 months, seed drying up to 10% moisture content appears quite satisfactory. However, for storage in sealed containers, drying upto 5-8 % moisture content depending upon particular kind may be necessary.
Harringtons thumb rule on seed moisture content :
For every one per cent decrease in seed moisture content the life of seed will be doubled. This is again hold good between 4- 12 C. Based on the tolerance and susceptibility of seeds towards moisture loss seeds are classified into
Orthodox – the seeds able to tolerate moisture loss and less seed moisture favours the storage. i.e. decreased moisture increased storage period. Eg. Rice, sorghum , and most of the cultivated species.
Recalcitrant – just opposite to the orthodox. Seeds not able to tolerate moisture loss. Required high moisture for viability maintenance.
Microflora, Insects and Mites
The activity of all these organisms can lead to damage resulting in loss of viability.The microflora activity is controlled by Relative Humidity temperature and Moisture Content of seed.
Treated seeds with fungicides can be stored for longer periods.
Fumigation to control insects will also help in longer period of stroage.
Fumigants - (e.g) methyl bromide, hydrogen cyanide, ethyline dichloride, carbon tetra chloride, carbon disulphide and napthalene and aluminimum phosphine.
Abiotic factors :
Relative humidity
Relative humidity is the amount of H2O present in the air at a given temperature in proportion to its maximum water holding capacity. Relative Humidity and temperature are the most important factors determining the storage life of seeds. Seeds attain a specific and characteristic moisture content when subjected to given levels of atmospheric humidities. This characteristic moisture content called equilibrium moisture content.
Equilibrium moisture content for a particular kind of seed at a given Relative Humidity tends to increase as temperature decreases. Thus the maintenance of seed moisture content during storage is a function of relative humidity and to a lesser extent of temperature. At equilibrium moisture content there is no net gain or loss in seed moisture content.
Temperature
Temperature also plays an important role in life of seed. Insects and moulds increase as temperature increases. The higher the moisture content of the seeds the more they are adversely affected by temperature. Decreasing temperature and seed moisture is an effective means of maintaining seed quality in storage. The following thumb rules by Harrington are useful measures for assessing the effect of moisture and temperature on seed storage. These rules are as follows.
1. For every decrease of 1% seed moisture content the life of the seed doubles. This rule is applicable between moisture content of 5-14%.
2. Fore every decrease of 5oC in storage temperature the life of the seed doubles. This rules applies between 0oC to 50oC.
Good seed storage is achieved when the % of relative humidity in storage environment and the storage temperature in degrees Fahrenheit add upto one hundred but the contribution from temperature should not exceed 50 oF.
Nomograph
Roberts (1972) developed formulae to describe the relationship between temperature seed m.c. and period of viability. From these relationships it was possible to construct a seed viability nomograph. These nomograph are helpful in predicting the retention of seed viability indefined storage environment for a particular period or to determine combinations of temperature and moisture content which will ensure the retention of a desired level of seed viability for specific period.
Gas during storage
Increase in O2 pressure decrease the period of viability
N2 and CO2 atmosphere will increase the storage life of seeds.
Seed storage sanitation or godown sanitation
• Storage environment should be free from insects and rodents
• Chemicals such as insecticides, fertilizers should not be stored along with seeds.
• Storage room should be kept coo and dry
• Fumigation may be done whenever needed
• Use wooden pallets for arranging the bags in cris-cross manner for effective ventilation on all sides of the bags.
• Seed bags should be stacked upto 6-8 tires depending upon density of seeds
• Restocking once in 3 months or less is important for prolonging seed viability
• Before storage disinfect the godowns by spraying malthion 50% E.C. @ 5 lit /100 m2 area.
• If old gunnies, cloth bags and containers are to be used these should be fumigated with aluminium phosphide.
• Size of the stack should be 30x20 feet facilitate fumigation under gas proof or polythene covers.
• Periodical inspections should be carried out and control measures to be taken i.e malthion 50% E.C. @ 5 lit /100 m2 area should be applied in every 3 weeks
• It must be borne in mind that fumigation, particularly repeated fumigation, may seriously reduce the vigour and even the germination capacity of seeds. Seeds with m.c. greater than 14% should be dried to below this value before fumigation
Maintenance of viability in storage
1. Store well mature seeds
2. Store normal coloured seeds
3. Seeds should be free from mechanical injruy
4. Seeds should be free from storage fungi or micro organisms 5. Seeds should not have met with adverse conditions during maturation 10. Storage godown should be fumigated to contro
l storage insects, periodically
6. Storage environment or godown should be dry and cool.
7. Seeds should be dried to optimum m.c
8. Required R.H. and temperature should be maintained during storage.
9. Seeds should be treated with fungicides before storage
11. Suitable packaging materials should be used for packing.
Organization set up and scope fro seed industry
Organizations involved in seed industry :
Organization set up of national and international seed companies
Managing Director
Chief of production
Production co-ordinator
Quality control Plant supervisor production manager
Operators Zonal officer
Production officer
Production Assistant
Field Assistant
Eg. Superior hybrid seed company organization set up
Board of directors
Chairman
Agri. Division
Executive Director
Production Director(Certified seed ) Production Director ( FS)
Production Officer Plan in Charge Prodn. Officer Plant operator
Field Asst. Plant supervisor farm supervisor
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