Growing Degree Days Requirement and Yield of Wheat Cultivars as Influenced by Irrigation Scheduling and Time of Sowing

The crop production characteristics are directly related with the temperature and relative humidity of atmosphere during crop growing season. Therefore, the main aim of this study was to highlights thermal requirement (GDD) of wheat varieties for sustainable yield. The field experiment were conducted during Rabi season 2016 and 2017 at Research farm, Rajasthan Agricultural Research Institute, Sri Karan Narendra Agriculture University, Durgapura, Jobner, Rajasthan to find out the response of wheat cultivars to irrigation scheduling under different sowing dates. Thirty six treatment combinations were investigated. Treatments comprises four irrigation levels: I1 (0.6 ETc), I2 (0.8 ETc), I3 (1.0 ETc) and I4 (1.2 ETc), three cultivars: C1 (Raj-4120), C2 (Raj-4079) and C3 (Raj-4238) and three dates of sowing: D1 (15th Nov.), D2 (30th Nov.) and D3 (15th Dec.) in Split plot design. The pooled analysis of data revealed that irrigation scheduling treatment I4 (1.2 ETc) recorded significantly higher value of yield and Growing degree days (GDD), By cultivar Raj 4079 observed the higher value of yield and GDD. Further, results showed that the wheat crop sown on 15th November obtained the maximum yield and growing degree days value with phenological stages. The number of days required to attain different phenological stages decreased with late sowing condition. This indicated that irrigation scheduling at 1.2 ETc should adopted in cultivar Raj 4079 at the sowing on 15th November to achieve maximum yield under hot climate of  Rajasthan.