Growth and yield prediction of wheat in relation to agroclimatic indices under irrigated and rainfed condition

Field experiments were conducted during rabi season of 2005-06 and 2006-07 in irrigated as well as rainfed conditions under subtropical condition of Jammu with three cultivars (PBW-343, RSP-81 and Raj-3765) of wheat sown on normal dates of sowing with four replications. The different agroclimatic indices were derived at different phenophases. The results revealed that crop experienced 1670 oC day, 19584oC day hours and 10371oC day hours accumulated growing degree days (GDD), cumulative photothermal (PTU) and heliothermal units (HTU), respectively for attaining the maturity under irrigated conditions. The variety PBW 343 took higher thermal time (1602oC days) as compared to Raj 3765 (1576 oC days) and RSP81 (1574 oC days) for attaining physiological maturity. Maximum heat use efficiency (HUE) by variety PBW343 (5.87 kgha-1 oC days) was found under irrigated situation as compared to other cultivars. GDD was found best indices for prediction of phenology followed by PTU, HTU.