Impact of Individual and Combined Water Deficit and High Temperature on Maize Seed Set: a Field Study

Drought and heat during flowering critically reduce maize seed set. Current understanding of how these conditions affect pollen release and silk development, which are key determinants of seed set, remains inadequate, particularly under combined water deficit (WD) and high temperature (HT) stresses. This study evaluated the effects of drought and heat on seed set in two maize hybrids, Zhengdan 958 and Demeiya 1, derived from temperate and cool-temperate regions, respectively. These hybrids were exposed to conditions of water deficit, high temperature, and combined water deficit and high temperature (WDHT) within semi-automatic rainout shelters in field ponds, enabling precise simulation of environmental stresses. Relative to controls, seed set in Zhengdan 958 decreased by 32