Updated: Feb 11, 2022
Introduction: What is seed?
SEED or propagule or seed material is that organ of a crop which is living in a rudimentary form and is used for propagation. Botanically, seed can be defined as a fertilized ovule which consist intact embryo, stored food, and a seed coat that has the capacity to germinate.
There are four essential factors for the germination of seed:
Capacity of seed to germinate
Types of pure seed
According to the international crop improvement association, pure seeds are of four classes:
Breeder seed Such seeds which are produced under the direct supervision of plant breeders and possess all the genetic characteristics required are known as breeder seeds. These seeds are costly and have high genetic value. These are used for the production of foundation seeds.
Foundation seed Also known as mother seed which is produced from breeder seed and is helpful for the production of certified seeds. The national seed corporation is responsible for the production of foundation seeds. It can be produced on government farms, agricultural universities, experiment stations, or on cultivar's fields under supervision from National Seed Corporation. Foundation seed is denoted by a white tag.
Registered seed These seeds are produced from foundation seed or registered seed itself and are helpful to produce certified seed. These have satisfactory purity and genetic identity and are produced by progressive farmers under supervision from State Seed Corporation. These are denoted with a purple tag.
Certified seed Certified seed is a progeny of registered seed, foundation seed, or certified seed itself. Satisfactory purity and genetic identity are present. It is certified and approved by State Seed Certifying Agency. It is tagged with blue color. State seed corporation is responsible for their production, but sometimes National seed Corporation also undertakes its production.
Agronomically, seeds can be classified as:
Improved seed Hybrid seed Composite seed Mutant seed
Seed dormancy means the inability of a vital seed to germinate under favorable conditions for a period of time. It is a reversible rest period that postpones metabolic, morphogenetic, and synthetic activities which are associated with the least physiological and moisture content.
How to break seed dormancy?
Seeds are treated with various methods to break their dormancy:
Seeds can be heated at 40 to 45 ° C for the various duration.
Seeds soaked for 36 hours can be treated at low temperature to 2-8° C for 12 to 24 hours.
Stratification is a method in which seeds are chilled at 0-5°C. This method is referred to as most chilling. It is usually practiced in seeds of pear, apple, walnut, plum, peach, etc.
It is a method in which the seed coat is softened so that water and gas can be absorbed easily. It can be practiced as follows:
a) Acid scarification – In acid stratification, dry seeds are treated with concentrated sulfuric acid, the duration of treatment varies from seed to seed. Seeds are washed thoroughly with water after treating with acid.
b) Mechanical scarification – In this, seeds are mechanically scarified so that moisture absorption can be increased. It is often practiced in the bitter gourd in which seeds are rubbed for 5 to 10 minutes with sand.
c) Hot water scarification – It is usually practiced in some legumes, in which dry seeds are soaked in hot water for 1 to 1.5 hours.
In some seeds, there are some inhibitors that cause dormancy like in coriander, couramin causes dormancy. To remove such kind of dormancy, seeds are soaked for 3 to 4 days in water, in which water is changed in every 12 hours.
Growth regulators or Chemicals:
There are various chemicals that break down the dormancy of seed-like gibberellic acid cytokinin ethylene potassium nitrates needs of chilgoza require exposure to extreme heat to break dormancy.
Certification of seed
Certification of seed is done by Certification Agency, notified under section 8 of Seed Act 1966.
State seed Certification Agency (SSCA):
State seed certification agency is responsible for seed certification, field inspection and also conducts seed tests which are required for seed certification.SSCA was registered under the state public society registration act.
Procedure for Seed Certification
Seed Certification is carried out as follows:
The Source of seed and other requirements which are used for raising the seed crop is verified.
Inspection of field
Post-harvest stages are supervised
Sampling and testing of seed
Tagging, sealing, and grant of certificate
Agencies that produce certified seeds
Currently, the National seed Corporation, State Seed Corporation, State Department of Agriculture, State Farm Corporation of India, Private companies, Cooperative and individual farmers produce certified seeds.
From where to order seeds?
Indian Institute of Horticultural Research (IIHR), Bengaluru https://seed.iihr.res.in/