PRODUCTIVITY OF SUNFLOWER UNDER HEAT AND WATER STRESSES IN NEWLY RECLAIMED LANDS

Abstract

Two field experiments were carried out at at the Experimental Station of Agricultural Production and Research Station, National Research Centre, El Nubaria region, El Behaira Governorate, Egypt during the summer seasons of 2014, 2015 to study the productivity of sunflower cv. Sakha 53 under heat and water stress and reduced the harmful effect of those stresses by using an antioxidant such as ascorbic acid Experiment included the following factors: - a- Sowing date 1- 21st April. 2- 21st May. 3- 21st June. b- Irrigation levels applied based on crop evapotranspiration (ETc) as follow: 1- Irrigation at 70% of ETc. 2- Irrigation at 85% of ETc. 3- Irrigation at 100% of ETc. c- Ascorbic acid 1- Control (Tap water and Tween20). 2- Ascorbic acid (sprayed three times at 30, 40, 50 days after sowing and the concentration of Ascorbic acid was 150 ppm / time and Tween 20 added to the spray solution). The experimental design was a split-split plot design with four replications. Main plots were occupied by the sowing date treatments, while the irrigation levels were distributed in the sub-plot and antioxidants treatments in sub sub-plot. Experimental unit area (sub sub-plot) was 12.25 m2. Seeds were sown in hills (3-5seeds in each hill)