Separating young-age rearing into dedicated chawki rearing centres addresses the sector’s central quality problem: farmers commonly skip egg disinfection, incubation and black-boxing, and rear early instars in dwelling houses. A chawki rearing centre supplies uniform, certified second-moult worms and converts ericulture from a household activity into a supply chain with an accountable quality checkpoint.
Chawki garden and batch planning
| Particular | Norm |
|---|---|
| Area under castor | 1 hectare (2.5 acres) |
| Variety and spacing | NBR-1 at 1 × 1 m |
| Chawki leaf yield | 6.75 MT / year |
| Batches per year | 18, to brush 90,000 DFLs |
| DFLs per batch | 5,000 |
| Leaf requirement | 375 kg per 5,000 DFLs (7.5 kg per 100 DFLs) |
Leaf and space requirement by instar
| Instar and day | Chopped leaf size | Leaf per 5,000 DFLs | Space per 5,000 DFLs |
|---|---|---|---|
| 1st instar, day 1 | 0.50 cm² | 25 kg | 300 sq ft (100 trays) |
| 1st instar, day 2 | 0.50 cm² | 37.50 kg | 600 sq ft (200 trays) |
| 1st instar, day 3 | 1.00 cm² | 50 kg | 900 sq ft (400 trays) |
| 1st instar, day 4 (pre-moult) | 1.00 cm² long strips | 25 kg | 1,200 sq ft (400 trays) |
| 2nd instar, day 1 | 1.50 cm² | 75 kg | 1,800 sq ft (400 trays) |
| 2nd instar, day 2 | 2.00 cm² | 125 kg | 2,400 sq ft |
Leaf requirement rises fivefold and space eightfold across six days — a chawki centre is planned around the last day, not the first.
Certification before distribution
| Assessment | Norm |
|---|---|
| Stage at despatch | 2nd moult; 8 trays per 100 DFLs |
| Missing larvae | < 2 % |
| Larval uniformity (undersized larvae) | < 2 % |
| Growth of larvae | 5.50 – 6.00 g per 100 larvae |
| Disease screening | Reject and burn the batch on detection of oval or ovo-cylindrical pebrine spores; disinfect the centre immediately |
Record the centre address, date of brushing, hatching percentage, DFL source and lot number, breed or eco-race and number of DFLs on every certificate.
Chawki rearing centre economics
| Head | Amount (₹) |
|---|---|
| Non-recurring cost | 99,133 |
| Recurring cost | 9,73,650 |
| Sub-total | 10,72,783 |
| Owner’s profit margin at 10 % of total cost | 1,07,278 |
| Risk factor at 5 % of recurring cost | 48,683 |
| Total expenditure per annum | 12,28,744 |
| DFLs brushed per year | 90,000 |
| Chawki rearing cost per 100 DFLs | 1,365 |
For one hectare of castor chawki garden. Establishment and maintenance of the garden assumes FYM at 30 MT/ha and NPK at 270 : 120 : 60 kg/ha/harvest.