Impact of Various Iron Forms on the Nutritional Status, Productivity, and Fruit Quality of Washington Navel Orange Trees.

This study was carried out during the 2022 and 2023 seasons on 12-year-old Washington navel orange trees budded on Sour orange rootstock planted at 5 x 5 meters apart (168 trees/fed.) under the surface irrigation system of a private orchard at Moshtoher village, Toukh region, Qalubia Governorate, Egypt, to study the effect of foliar spray with different iron forms, i.e., green iron nanoparticles (Fe-NPs), beside two tradional iron forms, ferrous sulfate (FeSO4.7H2O), and Fe-chelate (Fe-EDTA), on the leaf nutritional status, productivity, and fruit quality of Washington navel orange trees.". Each iron source was applied, covering the whole foliage of each tree canopy, whereas 5 liters were found to be sufficient in this regard. Besides, it is periodically applied five times per season at a one-month interval (in the 1st week of March, April, May, June, and July). The obtained results showed that all iron forms induced a remarked promotion in leaf nutritional status. Also iron forms enhanced yield , fruit physical and chemical characteristics compared with water sprayed trees (control). The best results with regards to foliar application were obtained by green Fe-NPs2 (1/40 dilution of the Fe-NPs stock solution) which significantly superior in this concern compared with control (water spray) and other iron treatments ,thus it could be recommended to spray Washington navel orange trees with green Fe-NPs2 (1/40 dilution of the Fe-NPs stock solution) five times per season at a one-month interval (in the 1st week of March, April, May, June, and July). to improve leaf nutritional status , maximize yield and enhanced fruit quality traits under the same experimental conditions.