One major issue that restricts wheat productivity in India that are susceptible to climate change is terminal heat stress. The present study evaluated the effect of different sowing dates on growth, physiological traits and yield performance of six wheat genotypes under terminal heat stress conditions. Field experiments were conducted during the rabi season of 2023–24 using three sowing dates: early (5th November), timely (25th November) and late (20th December), which progressively exposed the crop to increasing heat stress during reproductive stages. Growth parameters, yield attributes, chlorophyll content and grain yield were recorded and analysed using a two-way ANOVA. Results revealed that sowing date significantly influenced all major growth and yield traits. Early and timely sowing promoted greater plant height, biomass accumulation, spike length, grain weight per spike, test weight and ultimately higher and more stable grain yields. In contrast, late sowing imposed severe terminal heat stress, resulting in substantial reductions in growth, chlorophyll content and yield. Mean grain yield declined sharply from about 4.55–4.56 t ha-1 under timely sowing to only 1.41 t ha-1 under late sowing. Among the genotypes, UP2565 and UP2844 consistently performed better under stress, maintaining higher biomass, test weight and yield stability, indicating superior tolerance to elevated temperatures. Conversely, PBW343 was highly sensitive to terminal heat stress, exhibiting marked reductions in growth, photosynthetic capacity and yield. The study highlights the critical role of optimising sowing time to minimise heat-induced yield losses and underscores the importance of identifying heat-tolerant genotypes. Timely sowing combined with the use of resilient genotypes such as UP2565 and UP2844 can serve as effective strategies for sustaining wheat productivity under future climate variability.
