This study was carried out during 2013 and 2014 seasons to examine the effect of soil addition of Calcium nitrate at 1.0 kg/tree, borax at 25 g/tree and /or spraying of chelated-Ca at 0.03% and chelated-B at 0.025% on growth, yield and fruit quality of Washington Navel orange trees.
Varying sources and methods of application for both Calcium and boron had an announced effect on growth, leaf content of pigments and nutrients, yield and fruit quality .Using both calcium and boron via leaves was superiors than using both via soil and using chelated form of both nutrients was favorable than using calcium nitrate or borax for Ca and B, respectively. Using Ca and B via leaves in chelated forms at 0.03 and 0.025% respectively gave the best results comparing with using both together via soil.
A pronounced effect on yield and fruit quality of Washington Navel orange trees was obtained with spraying chelated-Ca at 0.03% plus chelated-B at 0.025 % three times at growth start, just after fruit setting and three weeks later.