ASHRY, M.R.K( 2012). Sunflower yield and some water relations under irrigation regimes and nitrogen fertilization.Annals of Agric. Sci., Moshtohor ISSN 1110-0419 Vol. 50(4), 407– 415
Abstract: The present investigation was carried out at Tamiea Agric. Res. Station, Fayoum Governorate during 2009 and 2010 seasons to study the effects of irrigation regimes, i.e. irrigation at I1: 30%, I2: 50% and I3: 70% available soil moisture depletion (ASMD) and three nitrogen levels, i.e. N1: 30, N2:50 and N3:70 kg N fed-1 and their interaction on yield, yield components and some crop water relations of sunflower (Eroflour cv.). The split- plot design with four replicates was used. The obtained results were as follow:
yield and all yield components i.e. plant height, head diameter and weight, seed weight head-1, 100- seed weight and seed protein content, obtained from irrigating sunflower at 30% ASMD and applying 70% kg N fed-1, surpassed significantly those obtained from the other treatments. However, the highest oil content were detected from irrigating sunflower at 30% ASMD and applying 30 kg N fed-1. Seasonal water evapotranspiration (ETC) reached its maximum values (58.81 and 57.74 cm in 2009 and 2010 seasons, respectively), as sunflower crop was irrigated at 30% ASMD and fertilized by 70 kg N fed-1. The daily ETc increased by decreasing the ASMD from 70 to 50 to 30% ASMD. The peak of daily ETc occurred on July. The KC (crop coefficient) as means during the growing seasons were 0.48, 0.79, 0.62, and 0.39 for June, July, August and September months, respectively. Irrigation at 30% ASMD and applying 50 kg N fed-1 gave the highest water use efficiency, i.e. 0.440 and 0.452 kg seeds m-3 water consumed in 2009 and 2010 seasons, respectively.
Keywords: (Sunflower, yield and yield components, evapotranspiration Kc and water use efficiency)
