Early-season heat waves cause biggest wheat yield losses but may prime later resilience

New research published in the *Journal of Experimental Botany* indicates that wheat crops suffer greater grain‑yield losses when heat waves strike before the plants reach the flowering stage, compared with heat events occurring later in development. The study, which examined a range of temperature spikes across multiple wheat varieties, quantified the differential impact on yield, showing that pre‑flowering heat stress can reduce grain output by a larger margin than comparable stress applied during the post‑flowering period.

The authors also identified a protective “priming” effect: exposure to an early‑season heat wave can lessen the damage from subsequent heat events. This acclimation response appears to trigger physiological adjustments that improve the plant’s resilience to later temperature extremes. The findings suggest that timing of heat stress is a critical factor for wheat productivity and may inform breeding strategies and agronomic practices aimed at mitigating climate‑related yield losses.