Evaluation of Some Morphological and Yield Component Traits Relationship to Soybean Seed Yield.

Studies on soybean seed yield in relation to morphological and yield component traits under different population and phosphorus levels was carried out at the University of Ilorin Teaching and Research farm, Ilorin Lat 80 29, N long 40 35 E Nigeria; over two years 2005 and 2006.Three soybean varieties at three population densities and four phosphorus levels were factorially combined in a randomized complete block and replicated four times. The result showed that the highest contribution to seed yield plant-1 was recorded in pod weight with coefficient of determination R2 = 0.998 while the lowest was observed in harvest index with R2 value of 0.078. Number of seeds and pods plant-1 with R2 value of 0.937 and 0.884 respectively, ranked second and third in their contributions to soybean seed yield plant1 in the study area. The regression equations for the combined morphological and yield component traits further showed that yield component traits with R2 value of 0.999 contributed more to seed yield than morphological traits with R2 value of 0.713. Invariably, the regression equation truly represented the relationships. Of the yield components traits, pods weight, number of pods and seeds plants-1 contributed more to the determination of soybean seed yield plant-1 than the other measured traits. These traits are therefore, considered as good indices for soybean breeders in varietal development, improvement and selection programme. It could also be a good indicator for soybean producers in variety selection for planting to increase yield in the study area. Key words: Coefficient of determination, yield components, pod, soybean, seed yield