Physiological studies for yield enhancement in blackgram (Vigna radiata L.)

A study was conducted during 2002 - 2003 in the department of Crop Physiology, Tamil Nadu Agricultural University, Coimbatore to investigate the physiological and biochemical effects of foliar spray of chemicals and plant growth regulator on physiological characters and productivity of blackgram. The treatments consisting of foliar spray of DAP 2%, Salicylic acid 100ppm+DAP2%+KCl 1%, salicylic acid 100 ppm +DAP2%+Boric acid 0.2%+FeSO4 0.5%+ZnSO4 0.5%, Na2NoO4 0.05%, urea 2%, urea foliar spray (equivalent N content as in DAP), humic acid 20 kg soil application+ 0.1% humic acid foliar spray, KCl 1% + humic acid 20 kg/ha as soil application + 0.1% foliar spray, KCl 1 % + humic acid 20 kg/ha as soil application, Brassinosteroid 0.1 ppm and control. Among all the treatments, 2% urea had the profound effect in improving the total chlorophyll content, soluble protein content and NRase activity. Foliar sprays of 2% urea recorded the highest grain yield of 955.20 kg/ha. The yield enhancement may be due to the improved morphological, physiological, biochemical and yield parameters viz., plant height, number of pods per plant, grain yield, harvest index, chlorophyll content, soluble protein content and NRase activity.