Assessment of sowing environment for wheat cultivars and evaluation of growing degree days for phenological stages in the Northwest Himalayan region of Himachal Pradesh

The date of sowing is a non-monetary input factor that plays a crucial role in field crop management. Based on the sowing time, management practices of crop production affect crop growth, development, and yield. Under varied environmental conditions, this factor may be useful in addressing low yields and combating/escaping stresses either due to diseases or due to any unfavourable environment. A field experiment was conducted during the rabi season of 2017–18 and 2018–19 to study the accumulated growing degree days (GDD) and performance of six wheat cultivars (HS 562, HD 2967, HD 3086, HI 1544, MACS 6222 and WR 544) under four sowing dates (5th November, 25th November, 15th December and 5th January). The study revealed that 5th November is the best date for sowing resulting in higher pooled grain yield of 4.85 Mg ha−1 and 3.94 Mg ha−1 at Bajaura and Malan, respectively. Significant reductions in the grain yield and yield attributes were observed when the date of sowing was set beyond 5th November. Among the cultivars tested, HS 562 gave a significantly higher pooled grain yield of 4.46 and 3.75 Mg ha−1 at Bajaura and Malan, respectively. Pooled data on physiological maturity revealed that variety HS 562 took the highest calendar days (168 days) and GDD (1573.42 °C days) to attain physiological maturity at Bajaura while at Malan HI 1544 and HD 3086 took the highest calendar days (156 and 155 days, respectively) and GDD (2055.41 and 2051.81 °C days, respectively) to attain their physiological maturity. From the study, it can be concluded that the early date of sowing provides the crop with ample duration to accumulate growing degree days resulting in a higher accumulation of photosynthates resulting in significantly higher yield attributes and grain yield. Therefore, 5th November is recommended as the best time for sowing of wheat crop whereas the sowing must not be delayed beyond 25th November. HS 562 was superior among the cultivars and is recommended for Malan and Bajaura regions for attaining higher yield.