Abstract

In order to investigate the effect of water stress on Mungbean varieties and its physiological responses to yield, a field experiment was carried out according to split plot design with twenty treatments combination and three replications during 2010 and 2011 at Crop Research Centre of Sardar Vallabhbhai Patel University of Agriculture and Technology, Meerut (Uttar Pradesh). The results indicated that drought tolerant varieties maintained highest xylem water potential (XWP), transpiration resistance (TR) and lowest leaf diffusive resistance (LDR) and canopy temperature minus air temperature (Tc – Ta) while drought susceptible varieties maintained lowest XWP,TR and highest LDR and Tc – Ta during the 1300 -1330 h. The rate of net photosynthesis decreased in all the varieties in treatment samples at various stages with the decrease in external CO₂ concentrations. Increase in free proline was observed from vegetative to active pod filling stages in all the varieties. The resistant varieties accumulated higher level of proline under water stress. SML-668 recorded the highest free proline content than all the other varieties. Variety SML-668 produced significantly higher grain yield.

Key words: Mungbean, water stress, yield and yield components.

Abbreviation

Tc, Canopy temperature; Tc- Ta, canopy minus air temperature differential;DAS, days after sowing; TR, transpiration rate; XWP, xylem water potential; PAR,photosynthetically active radiation; LDR, leaf diffusive resistance;  ROS, reactive oxygen species.