Effect of Sowing Date on Yield Component, Biomass Yield and Nutrient Content in Cowpea

Abstract

A field experiment was conducted at Ubon Ratchathani Field Crops Research Centre (fine-loamy, Siliceous, Oxic Paleustults) in 2000 - 2001, in order to study the effect of sowing date on grain yield, biomass yield and nutrient content in cowpea. The experiment was designed in a randomized complete block with 4 replications. The treatments were sowing cowpea in May, June, July, August and September. The results indicated that sowing cowpea seeds in May for both years significantly produced the highest number of pods per plant, number of seeds per pod, shelling percentage, seed size (100 seed weight) and grain yield. In addition, it accumulated the highest dry biomass yield and the contents of nitrogen, phosphorus and potassium in the residual cowpea plants. However, it was also found that sowing date had no effect on carbohydrate and protein contents in the cowpea grains.