Effect of water stress on yield stability, water productivity, and canopy temperature of rice genotypes

Abstract

A field experiment was conducted to evaluate the performance and water productivity of 15 rice genotypes under non-stress and drought-stress conditions in a warm-temperate climate. This study was laid out with a randomized complete block design at two research stations (Abbasabad and Katalom, Iran). Water deficit decreased the grain yield and increased the canopy temperature in all genotypes, but the response of water productivity to drought stress was not the same for the different genotypes. The maximum water productivity in non-stress and stress conditions (0.50 and 0.53 kg m -3 , respectively) were found in landraces. The canopy temperature was a reliable indicator for identifying drought-tolerant genotypes of rice. With each degree increase in canopy temperature, the grain yield decreased by 1 942 kg ha -1 . The biplot analysis demonstrated that landraces were the most suitable genotypes for cultivation under drought-stress and nostress conditions. A principal component analysis based on stress tolerance indices showed that Shastak and Sahel were the most tolerant genotypes to drought stress. Overall, Shastak with a maximum grain yield (4 595 kg ha -1 ), the highest water productivity, and savings of irrigation water by as much as 54% under conditions of drought stress may be introduced as a superior genotype for cultivation under water scarcity conditions and used in future breeding programmes.K e y w o r d s: cultivar, irrigation cut-off, stress tolerance indices, grain yield, water use efficiency