Influence of simulated post-anthesis water stress on stem dry matter remobilization, yield and its components in rice

Abstract

A field study was conducted to investigate the influence of foliar application of potassium iodide (KI) to simulate post-anthesis water stress on stem dry matter remobilization and yield. KI treatment had significantly reduced total chlorophyll content in all tested varieties and significant varietal differences were observed. KI application had no significant influence on number of spikelets per panicle or number of spikelets. However, the interaction between treatment and variety was found significant. The number of grains/panicle were reduced by KI spray and varietal difference was significant. Maximum number of grains/panicle was recorded in WGL-4 under control followed by DRR Dhan-39 under KI treatment. KI application had resulted in significant reduction in mean grain yield and the reduction was highest in PA-6129, Swarna and Akshayadhan and the reduction was comparatively less in Sampada, WGL-14, PA-6201 and PA-6444 indicating better carbon remobilization in these varieties. The mean remobilization efficiency was increased by KI application. The increase in remobilization efficiency was higher in WGL-14, PA-6201, Sampada and PA-6444 which incidentally produced higher yields under KI treatment due to increased remobilization of carbon from the vegetative organs which replenished the carbon lost due to impaired photosynthesis. Our findings suggest that KI application can be effectively used to identify rice varieties with high