The aim of this research was to study the effect of factors such as leaf age, salt type and concentration, number of foliar applications, and the nutritional status on the efficiency of foliar applications of potassium (K) in olive plants. The results obtained indicate that foliar applications of K effectively increased K content in K-deficient olive plants, and that foliar applications might be more effective on young leaves. Two foliar applications of KNO3 or the equivalent of other salts are enough to increase leaf K concentration. The leaf K concentration for the KNO3 treatment was 27 % higher than the control, an increase of 0,14% dry weight was found. The KNO3 treatment showed also the greatest plant dry weight of 6,38 g, although this was not significantly different from the control treatment (6,02 g).
Two foliar potassium nitrate sprays effectively increased K content in K-deficient olive plants
Restrepo-Díaz, H., M. Benlloch, and R. Fernández-Escobar. 2009. Leaf potassium accumulation in olive plants related to nutritional k status, leaf age, and foliar application of potassium salts. Journal of Plant Nutrition, 32(7): 1108-1121.