Abstract
This study was conducted to examine the growth and production of grass carp and tilapia cultured organically using napier grass in Bangabanbhu Sheikh Mujibur Rahman Agricultural University, Bangladesh from March-June, 2013. Three stocking ratios were tested: grass carp at 0.6 fish/m2 with GIFT tilapia at 0.3 fish/m2 (T1), grass carp at 0.6 fish/m2 with GIFT tilapia at 0.6 fish/m2 (T2), grass carp at 0.6 fish/m2 with GIFT tilapia at 0.9 fish/m2 (T3) and grass carp only at 0.6 fish/m2 as control (T4). Chopped fresh napier grass leaf was the sole nutrient input and provided twice daily. The water quality parameters were within suitable ranges for fish culture. Grass carp attained a daily growth increment ranging from 2.80-3.73 g/day and GIFT tilapia from 1.30-1.86 g/day. The combined yields was significantly higher (P<0.05) in stocking ratio of 1:1 (2.72 t/ha/90 days) compared to other stocking ratios. The result indicates on the basis of benefit-cost-ratio that the farmer’s income will be around double or more in the combined production of organic grass carp and tilapia with stocking ratio of 1:1 than the other stocking ratios. The density of grass carp should be further studied.