Response of Three Varieties of Cowpea( Vigna sinensis L.) to Different levels of potassium fertilizer under southern region conditions of Iraq

Abstract

A field experiment was conducted during  autumn season 2018 at Al Salam district, Maysan governorate. The aim was to evaluate some growth properties and grain yield of  three varieties of cowpea, Vigna sinensis L. (Local, Patton Boa and Atta E) grown under different levels of potassium sulphate  (0, 43, 86 and 129 kg h-1). The  experimental  design was applied according to the random complete block design in a split arrangement (Split Plots in RCBD). In on hand, the results showed a significant differences between the varieties. The local variety significantly gave highest plant length , leaf area, pods number, seeds number pod-1 and grain yield and which were 60.75cm, 2936.81cm2, 39.60 pod. plant-1, 7.69 seed pod-1, 99.93 g and 4.16 t. h-1 respectively. While the varieties Baton Boa gave highest weight of 100 seeds and gave 37.58 g. In other hand, as compare to the control, the addition of potassium up to 129 kg. h-1 lead to significant increase in plant length, leaf area, pods plant-1, seeds number pod-1 and grain yield plant-1 and total grain yield which were 53.33 cm, 3455.91 cm2, 51.61 pod. plant-1, 8.76 seed. pod-1, 125.93 g. and 5.25 T.h-1 respectively. Whereas, the control treatment (K0) gave the highest weight of 100 seeds (45.11 g). The Interaction between varieties and potassium  had a significant effect on almost  growth and yield characteristics.