Effect of Algae Extract and Zinc Sulfate Foliar Spray on Production and Fruit Quality of Orange Tree cv. Valencia

A two - year trial was conducted during 2012 and 2013 seasons on 9 years old Valencia orange trees budded on Volkamer Lemon rootstock grown in sandy soil under drip irrigation system at El Tall El Kbeer region, Ismailia Governorate Egypt. The study was a factorial experiment with two factors i.e. the first factor consisted of 4 levels of algae extract foliar spray (0, 1, 1.5 and 2 %) and the second one involved 2 levels of zinc sulfate foliar spray (0.2 and 0.4%) arranged in a randomized complete block design with three replicates for each treatment and each replicate was represented by two trees. Obtained results showed that foliar spray of algae extract and/or combined with zinc sulfate enhanced leaf mineral content, total chlorophyll, number of fruits per tree, yield and fruit quality. Generally, 2.0% algae extract provided with 0.4%zinc sulfate proved to be the most efficient treatment in enhancing all studied leaf parameters, tree yield and fruit quality.