Effect of Foliar Application of Different Potassium Forms and Concentrations on Leaves Nutrient Content, Fruit Yield and Quality of Fremont Mandarin

Abstract

This experiment was carried out during two successive seasons of 2020 and 2021 on 6 years old Fremont mandarin variety grown in sandy soil under drip irrigation system, in a privet farm located at Regwa district, Cairo / Alexandria Road, Beheira Governorate, Egypt, to elucidate the effect of foliar spray of different potassium forms; K2SO4; KNO3 and KCl, sprayed at three concentrations, i.e., 0.0%, 0.5% and 1%, three times a year (at the end of July, August, and September) on fruit yield and quality, and leaf minerals content. The obtained results indicated that all potassium forms at different concentrations and time of application had a positive effect on fruit yield, fruit physical and chemical characteristics, and leaf minerals content, in comparison with control treatment (T1). KCl at 0.5% (T4) was the best treatment to increase fruit yield parameters (as number of fruits /trees, yield as Kg /tree and tons /hectare). In addition, spraying K2SO4 at 0.5% (T2) and 1.0 % (T3) were found to be the most superior treatment in enhancing and improving fruit physical and chemical properties. Moreover, KNO3, spraying at 0.5% (T3) and 1% (T4) were more successful treatments in improving leave mineral status. Finally, it could be concluded that foliar spraying of different potassium forms be an efficient method for improving the most studied parameters of Fremont mandarin.