The response of haricot bean (Phaseolus vulgaris L.) to integrated use of phosphorus and manure, Eastern Ethiopia

Abstract

Haricot bean (Phaseolus vulgaris L.) production in Ethiopia is limited mainly due to soil nutrient depletion. Some attempts in using limited amounts of mineral fertilisers only brought small improvements in soil fertility and yield of the crop. Hence, to evaluate the response of haricot bean to integrated use of phosphorus and manure, an experiment was conducted with three replications of a randomised block design comprising the nine treatment combinations of three levels of P (0, 50 and 100 kg triple super phosphate (TSP) ha^-1) and three levels of manure (0, 5 and 7.5 t ha^-1). All the collected agronomic data were subjected to ANOVA using Genstat 18th Edition software. Results showed that the highest number of pods per plant (38.13) was recorded from the main effect of 100 kg TSP compared to the lowest (30.40) for the control. The highest effective number of nodules (221.1) was recorded from the main effect of 100 kg TSP. The highest harvest index (0.56) was recorded when 0 t manure ha^-1 was applied. Simple correlation analysis confirmed that grain yield was correlated with total number of nodules, effective number of nodules and number of pods per plant. The results showed that use of 100 kg TSP with 5.0 t manure ha^-1 gave the highest grain yield (3.40 t ha^-1 vs 1.95 t ha^-1 control). Increasing manure to 7.5 t ha^-1 gave the highest dry matter yield (7.2 t ha^-1 vs 3.5 t ha^-1 control). The integrated use of 50 kg TSP with 7.5 t manure ha^-1 was found beneficial for haricot bean producers in the study area. Combined applications of TSP and manure doubled haricot bean yield at Mechara area in Darolebu district of the eastern Ethiopian highlands.