Canopy Temperature as a Selection Parameter for Grain Yield and Its Components in Durum Wheat Under Terminal Heat Stress in Late Sown Conditions

Abstract

Relationship of canopy temperature (CT) with grain yield and its components were evaluated under terminal heat stress conditions, in Central India, during 2010–2013 growth season, in which 102 durum wheat genotypes were tested under late and very late sown conditions. The genotypes in late sown conditions showed higher grain yield/plant, biomass/plant, harvest index and test grain weight compared to very late sown conditions. The mean grain yield/plant and biomass yield/plant were 18.8 and 55.9 g, respectively, under late sown conditions, compared to 15.1 and 48.9 g under very late sown conditions. Genotypes MACS 3125, HI 8627, HI 8638, HI 8498, WH 896 and HI 8691 showed stable performance under both late and very late sown conditions over the years and hence exhibited high degree of tolerance to terminal heat. CT ranged from 21.0 to 24.7 and 20.2 to 24.9 °C under late and very late sown conditions, respectively. CT showed significant and negative correlation with grain yield/plant and biomass/plant under late and very late conditions and number of grains/spike and 1000 grain weight under very late sown conditions and hence can be successfully used as an important selection parameter in breeding programme at field. The study suggests that CT can be used as one of the important criteria for the selection of stable genotypes under late heat and very late heat stress conditions and can help in improving production and productivity of durum wheat under terminal heat stress conditions.