FIELD experiment was applied under sandy soil conditions to modify flood irrigation methods which are already used in numerous of citrus orchards aiming to save water consumption, increase irrigation efficiency and enlarge the potential wet area. It is established in an orchard of 5-year-old Valencia orange trees (Citrus sinensis) grafted on volkameriana lemon (Citrus volkameriana) located at Al-Adlia cooperative farms, Sharkia, Egypt. The treatments were; 1- Modified Blind Blocks (MBB), 2- Surrounding Square (SS), 3- Single Line (SL), 4- Comb Method (CM), 5- Single Railway (SR), 6- Double Railway (DR) and 7- Double Drip Lines (DDL). The studied parameters were; soil moisture content, tree root density, tree root horizontal extension and vertical penetration, tree canopy volume increment percentage, spring flush cycle and number of leafy inflorescences per shoot, fruit set percentage, fruit weight, fruit TSS and juice volume, theoretical yield and finally the water use efficiency (WUE). The obtained results showed that the modified irrigation methods which increase the water distribution efficiency and the potential wet area were DR, SR, CM SS and MBB; they successfully promoted all the studied parameters except the fruit TSS. While the SL and DDL methods that have less potential wet area around tree canopy resulted in less values. The results also showed that WUE in DR increased with about 38.9% in comparison with DDL.
Finally, from the economic point of view the DR irrigation method ranked as the first among all the others followed by SS.