Effect of potassium and zinc on yield, protein content and uptake of micronutrients on cowpea [Vigna Unguiculata (L.) Walp.]

A field experiment was conducted during kharif 2008 at, Junagadh on clayey soil to study the effect of potassium and zinc on quality and nutrient uptake in cowpea. Twelve treatments comprising four levels of potassium viz., 0, 20,40 and 60 kg K₂O/ha and three levels of zinc viz., 0,20 and 40 kg Zn/ha were tried in factorial randomized block design with four replications. The results of the study indicated that significantly higher grain (1587 and 1553 kg/ha) and stover (2047 and 2010 kg/ha) yields were recorded with application of 60 kg K₂O/ha and 40 kg Zn/ha, respectively. Application of 60 kg/ha potassium recorded higher protein content of grain as well as uptake of nitrogen, phosphorus, potash and zinc by grain and stover in cowpea crop. The maximum protein content of 23.59 per cent as well as higher nitrogen, phosphorus and potash uptake of 58.51, 7.33 and 12.04 kg/ha, respectively were found under 40 kg Zn/ha.