Seed cocoons are of paramount importance being the basic input for preparation of commercial silkworm seed and needs to be generated on scientific lines by maintaining the racial characters, vigour and disease freeness. Quality of the silkworm seed plays a decisive role in the success of the silkworm crop at the farmers’ level. The main objective of the seed crop rearing is to produce silkworm seed cocoons which conform to the norms, quality and disease freeness. Hence, a systematic approach is required to generate P1 seed cocoons of parental races to ensure production of quality hybrid dfls. Quality seed cocoons contribute significantly for the production of superior hybrid dfls. The success of a seed production centre lies in the generation of quality parental seed cocoons at required regular intervals and it forms the backward linkage for production of commercial silkworm eggs. The support of extension workers in supervision of the seed crop rearings is highly essential.

Thus, a system of identifying a nucleus farmer away from the seed area for generation of quality seed cocoons was introduced, which has now become a rule, especially for bivoltine. NSSO has adopted this concept and is now a champion in advocating and implementing the same, which is the key for the organization for production of bivoltine hybrid dfls with a high productivity.   

Adopted Seed Rearer (ASR) Concept

Seed cocoons are generated by the seed rearers in identified and notified seed areas. The Adopted Seed Rearers (ASRs) are the seed farmers with adequate facilities and experience who are selected by the seed producers or silkworm seed production centres to produce quality seed cocoons with assured market governed by quality linked pricing system. The salient features of this concept are :

Adopted Seed Rearers are usually from outside the seed area :

  • Receptive and progressive farmers with better infrastructure facilities and rearing skills only are adopted enabling easy adoption of new technologies
  • ASRs are isolated to facilitate easy monitoring of crops and disease incidence

Basic Requirements to adopt a seed rearer

  • Improved mulberry variety planted in wider spacing in well drained garden and good sunshine
  • Assured irrigation source and facilities
  • Separate chawki rearing facility with a provision to maintain recommended temperature and relative humidity conditions
  • Separate late stage silkworm rearing house with sufficient space and proper ventilation
  • Sufficient experienced manpower and rearing equipment
  • Experience and genuine interest in seed crop rearing
  • Preferably near to the egg production units

The seed cocoons after generation should be sold to the registered seed producers only. The seed cocoons which do not meet the quality characters of the breed are declared unfit for seed and rejected. Such rejected seed cocoons are marketed for reeling. The seed cocoons which are fit for seed but not purchased for want of demand would also be sold only for reeling purpose.

Purchase norms for seed cocoons

A quality linked pricing system is followed for the bivoltine seed cocoons purchased for the production of bivoltine hybrid dfls for purchase from the ASRs. A disease free P1  seed cocoon crop with a minimum yield of 50 kg / 100 dfls, 80 % pupation and 550 – 700 cocoons per kg qualifies for purchase.


Role of a grainage in generation of seed cocoons and implementation of the production plan

  • The seed cocoons are generated through registered seed cocoon producers, who are adopted by each SSPC as ASR.
  • These ASRs are selected based on the checklist at the beginning of each year
  • Based on the production programme, the P1 dfls are arranged by the concerned SSPC
  • The P1 dfls are incubated at 25⁰C and 85% RH, and black boxed (48h for treated and 72h for hibernated)
  • A day before hatching, the dfls are shifted to the chawki rearing room, where desired temperature and humidity is maintained.
  • The seed crop rearing is monitored by well experienced technical staff, who visit atleast 4-5 times during rearing period for guidance
  • During each visit, the unequal and lethargic worms are collected for microscopic examination and crop inspection card is maintained, where proper guidance is given for harvest of a good cocoons
  • The technical staff will ensure that only good crop which meet the norms of NSSO are brought to the SSPC for purchase
  • Quality linked pricing system is followed for purchase of the cocoons and a seed cocoon purchase committee, comprising of technical / administrative staff and the concerned ASR is constituted for purchase as per norms
  • The price of the cocoons ranges from Rs.750/- (80% pupation) to Rs.800/- (>95% pupation), with a rise of Rs.3/- for every 1% increase in pupation