Contributions of Plant Characters to Pod Yield in West African Okra Under Pluvial and Fluxial Agroecosystems

Abstract

West African okra [Abelmoschus caillei (A.Chev) Stevels] occurs as unselected variants with low pod yield. Using multiple statistical analyses could provide adequate information on contributions of plant characters to pod yield increase breeding efficiency. The objectives of the work were to evaluate the effects of agroecosystems and genotype on pod yield and relative contributions of plant characters in West African okra to develop efficient and stable selection criteria for pod yield improvement. Twenty-five genotypes were grown over a period of 4 years in two agroecosystems at the research farm of the Federal University of Agriculture, Abeokuta, Nigeria. The plant characters days to flowering, number of pods per plant, final plant height, days to harvest, pod length, pod width, pod growth rate, pod filling period, seed weight, and pod yield were measured. Results were analyzed by multiple statistical analyses: analysis of variance (ANOVA), genotypic correlation, factor analysis, principal component analysis, stepwise multiple regression analysis, path analysis, and cluster analysis. Significant effects occurred for genotypes, agroecosystems, and their interactions. Pod filling period was a stable character across agroecosystems. Though pluvial planted West African okra produced taller plants with a greater number of longer pods with heavier seeds, fluxial planted okra flowered and matured earlier with wider pods. Results of multiple statistical analyses indicated that pod growth rate contributed most to pod yield and to a lesser extent pod filling period, seed weight, and final plant height and provide useful information for efficiently improving pod yield in West African okra. West African okra breeding should focus on pod growth rate, which greatly affects pod yield. Determination of additional physiological and biochemical subtle but important yield-related characters might provide additional insights into pod yield.