Farming

Basically there are two methods of harvesting: culling (sometimes called cull-harvesting) and draining (drain-harvesting). The time to harvest depends partly on growth rate and the size of animals you want to sell. This, in turn, depends on your market requirements. It also depends on the pond management technique chosen. Cull-harvesting is used to harvest market-sized animals from the pond at intervals and removes the faster growing prawns. Annex 8 gives further information on size management. The rest of the prawns are caught when the ponds are drained at the end of the grow-out cycle.
In tropical ponds cull-harvesting usually starts 5-7 months after PL have been stocked, or sooner if juveniles have been stocked. After cull-harvesting commences, you should totally seine each pond once per month or partially seine it twice per month (i.e. seine half the pond twice per month or all of it once per month). Take out the market-sized animals and sell them. Keep the smaller ones and soft-shelled animals in the pond for further growth. After about 8-11 months, drain the pond and sell the whole harvest. In areas where water supply is short, some farmers utilize water drained during complete harvesting in other ponds to conserve water but, if you think of doing this, beware that you may be transferring a water quality or disease problem from one crop to the next. This practice is not recommended in this manual. After drain-harvesting, you can either prepare, refill and restock the pond immediately, or keep it empty until you have enough water available again and/or (in temperate zones) until water temperatures become suitable again for rearing.