Variation In Radiation Use Efficiency Of Wheat (Triticum Aestivum L.) As Influenced By Thermal Stress Management Strategies Under Late Sown Conditions

Field experiment was conducted at research farm, Department of Agricultural Meteorology, CCS HAU, Hisar located at 29 degrees 10 cent N latitude, 75 degrees 46 cent E longitude and 215.2 m altitude during rabi season (2007-08 and 2008-09) to study the variation in heat and radiation use efficiency of wheat as influenced by thermal stress management strategies under late sown conditions. The grain, straw and biological yields in pre-sowing treatment were maximum when overnight soaked seed sowing with 25% higher seed rate in dry bed followed by irrigation. Under post anthesis treatments, the highest grain and biological yields were observed in treatment of Urea (2.5%) + ZnSO4 (0.5%) spray at anthesis. The highest radiation use efficiency (RUE) was recorded in pre-sowing treatment when overnight soaked seed sowing with 25% higher seed rate in dry bed followed by irrigation at milking. Under post anthesis strategies, the maximum RUE was observed in treatment of Urea (2.5%) + ZnSO4 (0.5%) spray at anthesis.