Exogenous Application of Bio-regulators Improves Grain Yield and Nutritional Quality of Forage Cowpea (Vigna unguiculata)

This study was conducted at Fodder Farm, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab, India for two consecutive years (2008 and 2009) to investigate the effect of foliar application of bio-regulators applied at different concentrations viz. sodium benzoate (100 and 150 mu g mL(-1)), salicylic acid (50 and 100 mu g mL(-1)), CaCl2 (0.5 and 1.0%) and KNO3 (1.0 and 2.0%) on grain yield and quality of two forage cowpea cultivars CL 367 and Cowpea 88. Three foliar sprays of each bio-regulators were applied at weekly interval with the onset of flower initiation. Forage cowpea cultivar CL 367 exhibited significantly (p = 0.05) higher biological, pod, grain and crude protein yield than cultivar Cowpea 88. Neutral detergent fiber (NDF), hemicellulose and organic matter content of grain were also higher in cultivar CL 367. Phosphorus (P), potassium (K), zinc (Zn), copper (Cu), iron (Fe) and manganese (Mn) content were significantly better in Cowpea 88 cultivar. Foliar application of different bio-regulators increased the grain yield of cowpea by 12.9-32.7%. The highest grain and crude protein yield was recorded in foliar application of 50 mu g mL(-1) salicylic acid treatment. Grains produced under 50 mu g mL(-1) salicylic acid treatment had better quality in terms of more N, P, K, Zn, Cu, Fe, crude protein and organic matter content than the control. Also significant reduction in ether extract, NDF, hemicellulose and ash content of grain were recorded with foliar application of 50 mu g mL(-1) salicylic acid. Foliar application of KNO3 and CaCl2 also improved the yield and nutritional quality of the grain. The increased seed yield and quality of cowpea with bio-regulators certainly will improve the livestock health and milk production thereby improving the income of the farmers in South-East Asia and other tropical countries. (C) 2014 Friends Science Publishers