Evaluation of sugarcane by-product pressmud as a manure in carp culture.

The effectiveness of pressmud, a sugarcane by-product, was tested as a manure in the production of natural food and carp, by conducting two experiments. The first experiment, of 5 weeks duration, examined the effect of pressmud addition on water quality and natural food production. This study was carried out in fibreglass tubs (1.54 m3) with a 5 cm mud layer, employing pressmud at dosages of 5000, 10,000 and 15,000 kg ha(-1) for treatments T1, T2 and T3, respectively. Unfertilized tubs served as control (T0). The second experiment of 120-day duration to study the effect on growth, survival and quality of common carp was conducted in 25 m2 cement tanks with 15 cm-mud bottom, using the same dosages of pressmud. The control tanks in this experiment were manured with cattle dung at 10,000 kg ha(-1) (T0). Application of pressmud enhanced (P < 0.05) natural food production, with the greatest effect noted in treatment T3. Fish growth was significantly greater (P < 0.05) in treatments T2 and T3, there being no difference in growth between the control (T0) and 5000 kg pressmud treatment (T1). The greatest survival and production were obtained under treatment T2, which indicates that the dosage of 10,000 kg ha(-1) pressmud is optimal for carp culture. A significant effect (P < 0.05) of pressmud on carcass protein was observed. Organoleptic quality of both raw flesh and cooked meat of carp was not affected (P > 0.05) by pressmud treatment.