Effect of foliar application of different potassium formssupported by zinc on leaf mineral contents, yield and fruit quality of "Balady" mandrine trees

This study was carried out during two successive seasons 2010 and 2011 on 13 years old Balady mandarin rees budded on sour orange rootstock and spaced at 4×4 meters apart. Trees were grown in sandy soil at Giza Gvernorate. Foliar spraying with different potassium forms and as well as potassium nitrate (KNO₃), mono potasium phosphate (MKP) and potassium thiosulfate (KTS) at different concentration supported with chelated zinc a0.5% for all treatments were applied on the trees either pre or post bloom. The obtained results showed that lpotassium forms supported with Zn induced a remarked promotion in leaf mineral status. Also potassium forms nhanced yield and fruit physical and chemical characteristics compared with control trees. The best results wth regards to foliar application were obtained by MKP at 1.5% concentration with 0.5% chelated Zn which superor to improve leaves nutritional status. Whereas, enhanced yield and fruit physical and chemical characteristswere obtained by sprayed both KNO₃ and KTS at 1.5% concentrations with 0.5% chelated zinc.