New high in carp production in India through intensive polyculture.

摘要

Studies comprising two growth trials were conducted for maximizing carp production levels in still water ponds with emphasis on Indian major carps. The experiments were carried out for a period of one year with carps stocked at a density of 25 000 fingerlings/ha. While the species cultured in Experiment I were catla, rohu, mrigal and grass carp at a ratio of 35:30:30:5, silver carp and kalbasu were added in Experiment II as two other candidate species and limiting exotic silver carp and grass carpto only 24%. The management practices included application of Azolla 40 tonnes/ha annually as a biofertilizer, provision of aeration for 4-6 h during late night hours, balanced supplementary feed and fish health management. High mean survival rates of 88.1 and 93.5% were recorded in Experiments I and II, respectively. The mean annual gross and net production rates recorded were 15 666 and 11 987 kg/ha in Experiment I and 15 463 and 12 543 kg/ha in Experiment II, respectively. The corresponding feed conversion ratios recorded in two different sets of experiments were 2.38 and 2.58.