Determination of water use efficiency in groundnut by gravimetric method and its association with physiological parameters

Water use efficiency (WUE) and associated physiological parameters were measured in fifteen genotypes of groundnut (Arachis hypogaea L) grown in pots. Accurate measurement of WUE is possible by gravimetric approach. In this study there was an inverse relationship between mean transpiration rate (MTR) and WUE. A positive association between net assimilation rate (NAR) and WUE and total dry matter (TDM) and WUE indicated the possibility of identifying genotypes with WUE under mesophyll control. There was a strong correlation between TDM and LAD suggesting the role of leaf surface area in determining the biomass production. WUE was also estimated in field trials utilizing specific leaf area (SLA) values. The results show that, the WUE in the pot culture experiment was significantly correlated with the WUE estimated under field conditions. Among the genotypes, Tir 16 recorded highest WUE compared to all other genotypes.