Effects of N, P and K fertilizations on bud nutrient concentrations and fruit set of sweet cherry trees

Factors such as pollinators, pollen quality, pollinator variety, high temperatures, and nutrients affect the fruit set in sweet cherry trees. In this study, the effects of different doses of N, P, and K applied from the soil on fruit set of sweet cherry were investigated. Flower bud minerals (N, P, K, Ca, Mg, Fe, Cu, Mn, Zn, and B), fruit set ratios (FSR), and yield values were determined to compare treatments for 3 years (2015-2017). FSR (%) and yield (kg/tree) values ranged between 14.31-21.76 and 11.11-14.88 for N, 11.94-22.64 and 11.23-14.82 for P, 12.38-17.39 and 12.67-13.68 for K, respectively. N affected fruit bud N, Mg, Fe, Mn, and B concentrations, FSR and yield. Parameters other than FSR increased with increasing N doses and the highest values were obtained from the highest N treatment. FSR of the highest N dose was the same as the control treatment, but lower in the other treatments. P affected fruit bud P and Mg concentrations, FSR and yield. Fruit bud P and Mg concentrations increased as compared to the control treatment. The change in FSR and yield values could not be associated with the application dose, but showed linear changes with each other. K was effective only on FSR, the lowest values were obtained at the highest dose, while it was similar at the other doses. Fruit set ratio of sweet cherry trees under present experimental conditions could not be associated with the change in fruit bud nutrients due to N, P and K fertilization.