Canopy Temperature in Sorghum under drought stress: Influence of gas-exchange parameters

Abstract

Abiotic stresses, in particular, drought and heat, are the significant factors limiting the crop yield in arid and semi-arid regions, where sorghum (Sorghum bicolor (L.) Moench) is an essential component of the cropping systems. The combined stress due to drought and heat had significantly higher damage than each of its individual stress components. The impact of stress results from an effect on crucial physiological processes such as canopy temperature, membrane stability, chlorophyll content, tissue water retention, and photosynthesis. The genotypes CRS 99 and RNTN-13-39 have obtained the highest transpiration rates which are also possessing the highest canopy temperature depression. CRS 99 had the highest canopy depression of 2.2℃ followed by RNTN-13-39 showing 2.1℃ depression in the irrigated regime. Similarly, in the stressed regime, genotype RSV 1876 because of having the lowest canopy temperature resulted in the highest canopy temperature depression of 1.7℃ followed by Phule Anuradha with 1.6℃ depression. Hence, the present study was mainly focused on understanding the effects of drought stress on canopy temperature and its association with various photosynthetic parameters.