Response of Physiological Parameters in Greengram (Vigna radiata L. Wilckzek) cv. GAM-5 to Source Manipulation, Plant Growth Regulators and Chemical

Abstract

Background: Among the pulse crops mungbean is one of the richest sources of protein. There is great loss in the yield of mungbean due to various reasons may be biotic or abiotic constraints. To overcome the yield loss various physiological activities are studied. Physiological activities of the plant are greatly influenced by the source manipulation, plant growth regulators and chemical in mungbean. In correspondence to this, an experiment was conducted to study the physiological parameters in greengram.Methods: A factorial randomized block design in two respective years, i.e. 2016 and 2017 to study the response of source manipulation (nipping, 25% defoliation and 50% defoliation), plant growth regulators (GA3 and NAA at 25 and 50mg/l respectively) and chemical (Thiourea 500 and 1000mg/l) on the physiological parameters like Crop Growth Rate (CGR), Relative Growth Rate (RGR), Net Assimilation Rate (NAR) and Leaf Area (LA) in greengram at 30, 45, 60 and 75 DAS/harvest at Regional Research Station, Anand Agricultural University, Anand.\xa0Result: From the obtained results it can be proposed that the physiological parameters like crop growth rate, relative growth rate and net assimilation rate increased with the increasing phase and decreased at harvesting stage. While leaf area increased significantly at each growth phase. The treatment of nipping M2 was noted significantly higher value for CGR i.e., 8.42, 16.17 and 11.48 g/cm2/day/10, for RGR i.e., 0.544, 2.967 and 1.290 g/day, for NAR i.e., 0.466, 2.959 and 1.484 mg/cm2/day and for LA i.e. 96.87, 218.94, 381.88 and 588.78 cm2. While the treatment S2 GA3 25 mg/l was noted significantly higher value for CGR i.e, 8.60, 16.67 and 11.69 g/cm2/day/10, for RGR i.e., 0.568, 2.938 and 1.202 g/day, for NAR i.e., 0.372, 3.043 and 1.529 mg/cm2/day and for LA i.e., 96.61, 224.75, 382.20 and 580.42 cm2 contributing to the higher seed yield under M2 nipping treatment i.e., (1719.7 kg/ha) and S2 treatment i.e., GA3 25 mg/l (1714.1 kg/ha). Thus, GAM-5 had a better source-sink partitioning efficiency.