Effects of Nitrogen and Potassium Fertilization on Nutrient Content and Quality Attributes of Sweet Cherry Fruits

Abstract

Fertilizers are commonly applied to improve the yield and quality in orchards. But unbalanced fertilization negatively affects the nutrient contents of the fruits. Fruits with low energy and high mineral and vitamin contents are significant foods for human nutrition and human health. This study was carried out with ‘0900 Ziraat’ sweet cherry cultivar grafted on ‘Gisela 5’ rootstock in two consecutive years. The effects of different nitrogen (N) and Potassium (K) doses on nutrient content of fruits were investigated. Different doses of N (0, 50, 125 and 250 g N tree-1) and K (0, 50, 125 and 250 g K2O tree-1) were applied beneath the tree canopy in 6 replications and 1 tree in every replication in two consecutive years. Fruit samples were harvested from each tree and fruit colour, firmness, cracking index and nutrient contents (N, P, K, Ca, Mg, Fe, Zn and B) were determined. Fruit N content, N:K ratio, L*, a*, C* and firmness values increased with increasing N doses. While K fertilization did not have significant effects on K content and N:K ratio, it negatively influenced the N content of the fruits. It was concluded that N fertilization directly influenced fruit quality attributes, but K fertilization did not have any significant effects on fruit quality parameters.