This study was carried out during three consecutive (2016/019) experimental seasons on 15-year-old fruitful Valencia orange trees (Citrus sinensis L. Osbeck) Olinda cv., budded on Volkamer lemon rootstock, grown in reclaimed soil at two sites (South of El Tahreer& West of Al Nubaria regions) under drip irrigation system (Nile water) and subjected to the same cultural practices.This work aim to stu...