Figure 2.

Effects of high temperature stress on physiological and yield processes in grain crops. In brief, when plants are exposed to high air temperatures it leads to higher vapor pressure deficit and increased canopy temperatures, increased respiration, and decreased photosynthesis, leading to decreased biomass production. Higher temperatures shorten the growing season and shorten the grain filling duration, resulting in smaller grain size. Similarly, higher temperature causes reproductive failure leading to lower grain numbers. Fewer grain number and smaller grain size results in lower grain yield and harvest index.