Response of Washington Navel Orange Trees to Foliar Spray with Some Bio and Mineral Compounds

The present study was conducted on fruitful Washington navel orange trees grown at a private orchard during 2009 & 2010 seasons to evaluate the influence of some bio and mineral compounds i.e., Nofaterin and Biomagic foliar spray in different combinations with N, P, K and fertilizers on growth, productivity, fruit quality and nutritional status of Washington navel orange trees. Each of the tested nine treatments improved all the evaluated parameters dealing with: 1- growth parameters (No. of shoots / one meter limb, shoot length and thickness, No. of leaves per shoot and leaf surface area) 2- fruiting measurements ( fruit set and fruit retention percentage and yield/tree), 3- Fruit physical properties (fruit weight , dimensions , shape index , juice volume and peel thickness ) or chemical properties (juice TSS %, acidity %, TSS /acid ratio , total sugars and  Vitamin C content ), as well as leaf nutritional status (N, P, K, Ca, Mg, Fe, Mn  and Zn). However, the beneficial effect varied greatly from one treatment to another. Anyhow, Biomagic + (NH₄)₂SO₄ + K₂SO₄ at 1% + P₂O₅ at 100 ppm treatment was statistically the superior, followed descending by Nofaterin + (NH₄)₂SO₄ at 1% + K₂SO₄ at 1% + P₂O₅ at 100 ppm treatment. However, the control (water spray) treatment had the least values for all tested vegetative and fruiting parameters.