Effect of seed pelleting with diammonium phosphate and potassium dihydrogen phosphate and foliar spray with diammonium phosphate on growth and yield of rainfed cowpea (Vigna unguiculata)

An experiment was conducted during 1995 and 1996 to study the influence of seed pelleting with diammonium phosphate (DAP) and potassium dihydrogen phosphate (KH₂PO₄) in comparison with DAP spray in rainfed ‘Paiyur 1’ cowpea [Vigna unguiculata (L.) Walp.] under North-Western Agroclimatic Zone of Tamil Nadu. Soil application of recommended inorganic fertilizers (RIF) + 2% DAP spray twice (first at flowering and second at 15 days after first spray) showed the highest plant height. Branches and pods/plant, seeds/pod, 100-seed weight, dry-matter production, seed yield, net income and benefit: cost ratio. Seed pelleting with DAP and KH₃PO₄ did not influence the above-said parameters appreciably.