Abstract:
An experiment was conducted for 98 days in the Lake Victoria Basin to investigate the interactions of
fish and rice growth performance in rice paddies. The experiment was laid out in a split-plot design,
with rice cultivar as the main plot and method of rice-fish culture as the sub-plot. Treatments consisted
of two levels of rice-fish culture and three cultivars of rice. Rice cultivars used were; ITA, BR 11 and IR
2793-80-1 obtained from the National Irrigation Board (NIB), Kenya.
Clarias gariepinus
, (15 ± 0.4 g) were
stocked at 6 m
-2
and given supplementary diet containing 35% crude protein and 7% lipids at 2×
maintenance level. There was significantly less incidence of stem-borers in rice-fish polyculture
compared to rice monoculture (P< 0.05). Rice-fish polyculture gave significantly higher rice yield than
rice monoculture (453 ± 1.0 gm
-2
). The seed yield differed significantly (P< 0.05) between the rice
cultivars with ITA giving the highest yield followed by IR and BR. There were significant differences in
growth performance of
C. gariepinus
in the treatments (F = 4.518,df = 2, P = 0.014) with best growth
recorded in the Fish-ITA and least in Fish-BR. Mean net annualized fish production was highest (3,767 ±
300 Kgha
-1
yr
-1
) in the ITA-Fish plots with no statistical differences recorded between BR-Fish and IR-
Fish plots. Fish survival ranged from 79.9 to 82.6 percent in Fish-IR, Fish-BR and Fish-ITA respectively.