Yield and Yield Related Attributes of Wheat Cultivars Grown under Different Thermal Regimes and Plant Densities

This field study, conducted over two years (2023–24 and 2024–25) at the Student’s Instructional Farm, Acharya Narendra Deva University Agriculture and Technology, Ayodhya, India, aimed to evaluate the effects of three thermal regimes (T1: 12th Nov, T2: 26th Nov, T3: 10th Dec), three row spacings (S1: 15 cm, S2: 22 cm, S3: 30 cm), and three wheat cultivars (V1: DBW 187, V2: HD 2967, V3: HD 3271) on wheat yield (grain, straw, biological yield, and harvest index) and yield attributes (spike length, number of spikes per plant, number of grains per spike, test weight, and effective tillers). A factorial randomized complete block design (RCBD) with four replications was employed for the experiment. The findings indicated that the optimal thermal regime (T1) significantly enhanced yield and yield attributes at all stages compared to delayed sowing (T2 and T3), revealing the negative impacts of late sowing and thermal stress. Among the cultivars, V1 consistently demonstrated superior growth and adaptability, yielding the highest values for all traits. Moderate row spacing (S2) was more effective than narrow (S1) and wide (S3) spacings in promoting effective tillers and harvest index. These results highlight the importance of careful selection of sowing time, cultivar, and row spacing for improving wheat productivity under diverse thermal conditions. The study offers valuable insights for developing strategies to build climate-resilient wheat production in subtropical agro-ecosystems.