Effect of different irrigation methods on fruit quantity andquality and vegetative growth of Thomson navel orange

A 3-year field experiment was conducted to compare fruit quantity and quality of Thomson navel orange (on flying dragon rootstock) under four microirrigation systems. The experimental design was complete randomaized blocks with four treatments and six replications. The treatments consisted of four microirrigation systems: Microjet, Bubbler, two and three in-line drippers. Trees were irrigated during spring and summer seasons when tensiometers indicated the soil tension of 50 kPa. The amount of applied water in each treatment was measured by water meter. In middle November, fruites of one tree per replication were picked and the yield of trees were measured. Then, 25 fruits per tree were randomly separated and peel thickness, diameter, length, weight, TA and TSS were measured. Trunk diameter and canopy volume were measured in Mar. 2003-2005 and Nov. 2005. Comparison of means showed that the yeild of trees in microjet and two drippers irrigation were siginifficantly higher than bubbler and three drippers systems. The yeild of trees in two drippers and microjet treatments was 16.6 to 19.2% more than bubbler and three drippers. Irrigation systems had no significant effect on the vegetative growth of trees and fruit peel thickness, diameter, length, weight, TA and TSS.