Foliar Potassium Application on Olive Tree

The objective of this work was to evaluate the effects of potassium (K) fertilization on vegetative growth, fruit production and leaf mineral content of olive tree (Olea europeae L.) under rainfed condition. Different fertilizer, techniques and rates of application were applied in 2003 on Chemlali olive. The potassium fertilizer used was potassium nitrate. The foliar fertilizer rates were 50 and 100% of the tree requirement and for soil spreading the rates were 100% and 200% of the tree needs. A control was also observed with no applied fertilization as used on the experiments region (Sfax). The results did not show any significant effect of treatment on olive vegetative growth. However, foliar treatment increases significantly leaf area. Foliar fertilization at 100% accelerates fruit maturation, increases fruit weight, pit ratio and polyphenol, respectively to 0.81g, 3.65 and 59.37ppm. No significant differences on fat content and acidic composition were observed. Leaf mineral analysis revealed that K fertilization increased significantly K foliar content with no differences for the others mineral elements (N, P, Mg).