Effect of N fertilizing on gas exchange, leaf photosynthetic performance and nutrient concentrations of Sweet Cherry cv. 0900 ziraat

In this study, the effect of nitrogen (N) fertilization on gas exchange and the photosynthetic performance of cherry leaves were investigated. In the study, 4 different doses of N were applied from the soil, and N, P, K, Ca, Mg, Fe, Mn, Zn, and B concentrations were determined in leaf samples taken from the middle part of the shoots 65-70 days after full flowering. Assimilation rate (A), the concentration of intercellular CO2 (Ci), transpiration rate (Tr), stomatal conductance to water vapor (Gsw), total conductance to CO2 (Gtc), and total conductance to water vapor (Gtw) were measured simultaneously with leaf collection for mineral analysis. Leaf water use efficiency (WUE) and instantaneous carboxylation efficiency (ICE) were calculated. N fertilizing affected the leaf accumulation of some macro (N, P, K, Ca, and Mg) and micro (B) nutrients. As N doses increased, N content of leaf increased, while decreasing leaf P, K, and B contents. N fertilizing negatively affected Tr, A, Gsw, Gtw, Gtc, and ICE. While there were negative correlations between leaf N concentration and gas exchange and leaf photosynthetic performance, they were positive for P and K. It means that changes in gas exchange and leaf photosynthetic performance were not related to increasing leaf N concentration, but decreasing leaf K and/or P concentrations depending on N fertilizing.