ABSTRACT

Eighteen genotypes of soybean were evaluated in 2005 cropping season for yield and associated characters at the research farm of Michael Okpara University of Agriculture, Umudike in the Southeastern, rainforest zone of Nigeria. The treatments were laid out in a Randomized Complete Block Design with three replicates. The genotypes were screened for plant height, number of nodes per plant, number of leaves per plant, number of' pods per plant, 100-seed weight and 'seed yield per hectare. The analysis of variance showed a significant variation among all the six attributes examined (P0.05). Wide ranges of phenotypic, and genotypic variability were also observed for most of the traits. 1-ligher values of error variance than the genotypic variance was obtained. Also, the phenotypk coefficient of variance was shown to be higher than the corresponding genetic coefficient of variation for all the characters studied. Moderate values of genotypic coefficient of variance (GCV) and Heritability were observed in number of leaves per plant, 100- seed weight and seed yield per hectare. The result of linear correlation • analysis showed that only 100-seed weight was significantly and positively associated with yield. Similar result was obtained from the linear regression analysis and the multiple regression (stepwise) analysis. Therefore, selection for seed size can lead to improvement of seed yield in soybean in this agro ecology.