Effect of irrigation system conversion on some growth and fruiting aspects of orange trees

This work was carried out in the three successive seasons of 2003, 2004 and 2005 on about 44-year-old Washington navel orange (Citrus sinensis L. Osbeck) trees budded on sour orange rootstock. The experimental trees were healthy, approximately uniform in size and vigor and grown in sandy loam soil at 6 m apart in a private citrus orchard at Belbis district, Sharkia Governorate. The orchard had been flood irrigated during its entire 44-year history. This study was designed to evaluate the performance of mature Washington navel orange trees after being converted from flood irrigation to several microirrigation systems and identify the optimum irrigation system and requirements required to converse flood irrigated mature citrus trees to one of the pressurized microirrigation systems.