Abstract:
Eleven rice genotypes obtained from National Cereals Research Institute, Badeggi, Nigeria, and a local variety were evaluated under field culture in Nsukka for a period of two years (1998 and 1999). Multiple correlation and path coefficient analysis were used to study yield and yield components. Genotypic stability analysis was performed on the yield and the two traits most related to yield using mean yield-coefficient of variation (CV). The genotype, ITA 324 had the highest grain yield and percentage fertile spikelets in both years. All the yield components were significantly (p = 0.05) and positively correlated with yield in the second year. Tiller number per plant and percentage of fertile spikelets had the strongest genotypic correlations with yield in both years. The yield stability estimates of the genotypes and the traits most related to yield showed that the genotypes independently expressed their traits in the different stability groups. Four groups of yield stability conditions were established as - high yield and low variation, high yield and high variation, low yield and low variation and low yield and high variation. The direct effect of percentage fertile spikelets on yield was positive and of higher magnitude than the direct effects of tiller number, panicle number, spikelet number and 1000 grain weight. Selecting upland rice genotypes with stable and high number of filled grains would sustain high yields in such genotypes especially as the yield components are complementary in action.
