In this study, foliar potassium and calcium fertilizers were applied singly and combined to two different apple tree varieties in order to evaluate the effects of potassium and calcium fertilizers on yield, quality and nutrient levels and to recommend fertilization. For this purpose, the Red Chief and Golden Delicious varieties were used. Leaf analyses (N, P, K, Ca, Mg, Fe, Cu, Zn, Mn), the SPAD measurement, pomological analyses (fruit weight, width, length, skin color, flesh firmness), and yield were made. Differences in nitrogen and phosphorus between the varieties and applications were found to be insiginificant, while Golden Delicious was found to be significantly richer than Red Chief in the content of K, Ca and Mg. According to the values obtained, all the micronutrients except Fe were taken up in greater amounts by Red Chief than by Golden Delicious. Differences between the cultivars in the width, height and weight of fruits were significant, but the differences in the same parameters due to the tested applications were found to be insignificant. When examined in terms of firmness, the difference between the varieties was insignificant, and the difference between the applications was significant, as Golden Delicious achieved higher values ​​than Red Chief. In terms of the leaf SPAD value, Red Chief scored higher than Golden Delicious. Using an appropriate fertilizer for a given variety is important for increasing yield, quality and nutrient concentration when potassium and calcium fertilizers are applied separately or together in similar climatic and soil conditions. In this study, the yield was increased by applying K and Ca separately or together. Among the quality parameters, it was determined that the K+Ca application was more effective than separate applications of K and Ca in terms of fruit firmness. Although there is sufficient potassium and calcium in the soil, 1% Ca + 1% K application to the apple tree leaves can increase fruit quality and yield. The results will be useful for future studies.

28.1.2023