Generation system of seed multiplication is nothing but the production of a particular class of seed from specific class of seed up to certified seed stage. The choice of a proper seed multiplication model is the key to further success of a seed programme. This basically depends upon, a. The rate of genetic deterioration b. Seed multiplication ratio and c. Total seed demand (Seed replacement rate) Based on these factors different seed multiplication models may be derived for each crop and the seed multiplication agency should decide how quickly the farmers can be supplied with the seed of newly released varieties, after the nucleus seed stock has been handed over to the concerned agency, so that it may replace the old varieties. In view of the basic factors, the chain of seed multiplication models could be.,
a. THREE - Generation model - Breeder seed - Foundation seed - Certified seed
b. FOUR - Generation model- Breeder seed - Foundation seed (I)- Foundation seed (II) - Certified seed
c. FIVE - Generation model Breeder seed - Foundation seed (I)- Foundation seed (II) -Certified seed (I) - Certified seed (II)
For most of the often cross pollinated and cross pollinated crops 3 & 4 generation models is usually suggested for seed multiplication .e.g. Castor, Red gram, Jute, Green gram, Rape seed, Mustard ,Sesame , Sunflower & most of the vegetable crops. Opel Green Classes of seed
The four generally recognized classes of seeds are: Breeder's seed, foundation seed, registered seed and certified seed.
a) Nuclus seed: The initial hand full of seeds obtained from selected individual plants of a particular variety, for the purpose of purifying and maintain that variety, by originating plant breeder.
b) Breeder's seed: Progeny of Nucleus seeds, its production is directly controlled by the originating or the sponsoring breeder or institution, providing for the initial and recurring increase of foundation seed.
b) Foundation seed: The Progeny of breeders or foundation seed handled to maintain specific genetic purity and identity. This seed is the source of all other certified seed classes.
d) Certified seed: The progeny of foundation or certified seed that is handled so as to maintain satisfactorily genetic identity and purity and that has been approved and certified by the certifying agency.
DIFFERENCES BETWEEN CERTIFIED SEED AND TRUTH FUL SEED
Truthful labelled seed
Certification is voluntary
Truthful labelling is compulsory for notified kind of varieties
Applicable to notified kinds only
Applicable to both notified and released varieties
It should satisfy minimum field and seed standards
Tested for physical purity and germination
Seed certification officer, seed inspectors can take samples for inspection
Seed inspectors alone can take samples for checking