24-Epicastasterone and KH₂PO₄ protect grain production of wheat crops from terminal heat impacts by modulating leaf physiology

Heat stress during the grain filling is one of most critical factors impacting yield in winter wheat. In a two-year field experiment, we studied effects 24-Epicastasterone and KH2PO4 on heat-stressed wheat applied different times. A completely randomized block design was used with three reagents, that is, 24-Epicastasterone, H2O spraying times, pre-heat, under-heat post-heat. Two cultivars, Huaimai 33 Annong 0711 were subjected to 7 d post-flowering heat using plastic tents. Our study suggests greater weight plants achieved through sustaining leaf greenness higher assimilates supplies grains. When sprayed either or could sustain relatively photosynthetic capacity by up-regulating antioxidant enzymes reduced damage lipid membranes chlorophyll. We also found more effective improving physiology than 24-Epicastasterone. Further analysis showed pre-heat post-heat pronounced protecting from injury under stress. Thus, prior post incidence recommended protect crops terminal