The effects of pruning and fertilization applications on yield and some fruit characteristics of pistachio nuts (Pistacia vera L.)

This research was carried out on "Kirmizi" pistachio nut cultivar in order to determine the effects of different pruning and fertilization treatments on yield, and also some nut characteristics in pistachio (Pistacia vera L.). Nitrogen and phosphorus were applied using ammonium sulphate and TSP at the rate of 0 (Control-N-0), 800 (N-1), 1000 (N-2) and 1200 (N-3) g tree(-1), and 0 (Control-P-0), 200 (P-1), 400 (P-2) and 600 (P-3) g tree(-1). The trees were pruned by 2 different methods such as traditional pruning that is commonly applied in this region (PR1), and cutting of apical flower buds besides traditional pruning (PR2). At each harvest season, yield per tree, nut weight, nut splitting rate, empty nut rate and flower bud abscission rate were recorded. Differences in yield values obtained from trees, which were treated with different fertilization and pruning treatments were not significant. The interactive effects of fertilization doses and pruning treatments were significant on nut weight, nut splitting, and empty nut rates in all years, and on fruit bud abscission ratio only in the 'on' year. In relation to yield and all other characteristics, higher values were obtained from applied PR2 trees, as well as the trees on which nitrogen and phosphorus fertilization was treated.