FARRAG, F.R.M.; ASHRY, M.R.K; YOUSEF, K. M. R. AND ABDOU, S.M.M.( 2013). ( CROP-WATER RELATIONS AND YIELD OF ONION AS AFFECTED BY RIDGE WIDTH AND IRRIGATION INTERVAL.) Minufia J. Agric. Res. Vol. 38 No. 2(2): 507-517, 2013.
Abstract: Two field experiments were conducted at Tamiea Res. Station, Fayoum Governorate, Egypt, during 2010/2011 and 2011/2012 seasons, to study the effect of ridge width treatments, i.e. 50 , 75 and 100 cm (beds) and irrigation interval treatments e.g. irrigation every 21 , 28 and 35 days on yield, yield components and some crop-water relations of onion crop (Giza 20 cv.). The experimental treatments were assessed in a strip- plot design with four replicates. The main obtained results were as follows:
1.Ridge width, irrigation interval treatments and their interaction significantly affected dry bulbs yield and its components in both seasons, except dry bulb diameter in first season.
2.The highest averages of plant height, leaf No. plant-1, bulb weight, bulb diameter and dry bulbs yield, in the two successive seasons, were detected from transplanting onion on ridges of 50 cm width and irrigation at 21 days interval. On the contrary, transplanting on beds (100 cm width) and irrigation at 35 days interval gave the lowest averages of dry bulbs yield and all of yield components in the two seasons.
3.Seasonal evapotranspiration (ETC), as a function of the interaction of the adopted treatments were 35.97 and 37.92 cm in 2010/2011 and 2011/2012 seasons, respectively. The highest ETC values, i.e. 41.07 and 43.05 cm were recorded from transplanting onion on ridges of 50 cm width and irrigation every 21 days in 2010/2011 and 2011/2012 seasons, respectively. Transplanting on beds and irrigation at 35 days interval gave the lowest ETC values which comprised 30.62 and 31.94 cm in the two successive seasons.
4.The crop coefficient (KC) values (estimated for the highest yield treatment) were 0.46, 0.64, 0.75, 1.04, 0.68 and 0.48 (average of the two seasons) during Dec., Jan., Feb., March, April and May, respectively.
5.The highest water use efficiency values (9.41 and 9.47 kg dry bulbs m-3 water consumed) were observed from transplanting onion on ridges of 50 cm width and irrigation every 21 days in 2010/2011 and 2011/2012 seasons, respectively. In order to manage the limited water resources efficiently and to obtain reasonable figures for water productivity, it is advisable to irrigate onion every 21 days and transplanting on ridges of 75 cm under Fayoum Governorate circumstances.
Keywords: (Onion yield, yield components, ridge width, irrigation interval, onion crop- water relations, water use efficiency . )
