Combined usage of organic and inorganic potassium on pod characteristics of cowpea (Vigna uncuigulate L.) cv Waruni

Abstract

A field experiment was laid out in Randomized Complete Block Design with five treatments and three replications to evaluate the pod characteristics of cowpea cywaruni at the Faculty of Agriculture, Eastern University of Sri Lanka. The treatments included recommended rate (75 kg/ha) of Muriate of potash (MOP) as a control (T1) and the MOP was replaced by Rice Husk Ash (RHA) at the rate of 25% (12), 50% (13), 75% (T4) and 100% (T5). Application of 100% RHA was 3500 kg/ha. All other agronomic practices were done according to the Department of Agriculture recommendation. Field data were collected at harvesting stage. Results revealed that application of RHA at the rate of 75% with 25% of MOP increased all the tested parameters including pod number per plant (9.23), seed number per plant (77.59), fresh weight of pods per plant (86,77 g), dry weight of pods per plant (9.41 g) and air dried weight of seeds per plant (9.33 g). Therefore, it could be concluded that application of RIHA as a source of potassium at a rate of 75% with 25% of MOP is favourable for yield advancements in cowpea.