Growth and yield responses of Sphenostylis stenocarpa (Hochst ex. A Rich) Harms (African yam bean) to potassium application

Abstract

Responses of African yam bean (Sphenostylis stenocarpa) to supplementary application of potassium (K) on soil were examined. Effects of the varying levels of potassium on vegetative growth, flowering, pod maturation, yield and yield components were also evaluated. There seems to be no significant mean effect (P > 0.05) upon K application on the above ground parameters of African yam bean. Similarly, soil enrichment with K had no significant effect (P > 0.05) on below ground parameters of the crop. Mineral elemental applications had no significant effect (P > 0.05) on days to 50% flowering but their effect on the number of flowers per plant for example 192.75 ± 9.87 flowers per plant in 550 kg K/Ha treatment as against 145.13 ± 18.02 flowers per plant in the control treatment were significantly different. However, grain yield per hectare increased significantly (P < 0.05) with increasing levels of K application when compared to controls. Key words: African yam bean, mineral, potassium, grain, yield.