HEAT STRESS EFFECTS ON THE PERFORMANCE OF SOME EGYPTIAN WHEAT CULTIVARS

Abstract

Six commercial bread wheat cultivars were planted in Abo Elmatameir region, Behera governorate, Egypt, during the two successive seasons 2021/2022 and 2022/2023 under three sowing dates; 20 November (recommended), 20 December, and 20 January (late as heat stress). A split-plot arrangement was used in a randomized complete block design (RCBD) with three replicates. The three sowing dates were randomly assigned to the main plots, while the six wheat cultivars were assigned randomly to the subplots. The primary goal of this investigation was to determine the most appropriate cultivar for heat stress and recommended conditions. Our results concluded that heat stress had a significant adverse impact on most of the studied traits. Sids14 exhibited the highest spikes and flag leaf area among the evaluated cultivars in both seasons. Sakha95 was the tallest cultivar in both seasons, whereas Misr2 outperformed other tested cultivars regarding the number of spikelets/spikes, harvest index, and grain yield. Misr1 showed the highest straw yield, while Giza171 and Sids14 presented elevated canopy temperatures. Furthermore, Giza171 had the highest 1000-grain weight, grain yield, and straw yield under the recommended sowing date. Additionally, Sakha95 had the highest value of proline content under heat-stress conditions. Moreover, Misr2 and Giza171 were the ideal cultivars for the late-sowing conditions. The results showed that evaluating wheat cultivars under late heat-stressed conditions in Egypt is required to face the effects of global warming and reduce large wheat imports.