Evaluation Effects of Chemical Thinning on the Quality and Quantity of Fruits in Two Peach Cultivars

This research was carried out in order to evaluation effects of chemical thinners (Urea and NAA) on quantitative and qualitative characteristics on 2 peach cultivars (Sun crest and Dixired) in Meshkinshar region. Experiments were carried out based on randomized complete block design with five treatments and three replications for 2 years. Treatments were urea (10 and 12%), NAA (15 and 20 ppm) and control trees take place at full bloom stage. Characteristics such as flower abscission, fruit weight, fruit sizes, acidity, TSS and yield were measured. Results showed that effect of different concentrations of urea and NAA on flower abscission, fruit weight, fruit size, acidity, TSS and yield in cultivars were significant. Different concentrations of urea and NAA causes increased flower abscission, fruit weight, fruit size and decreased yield in studied cultivars in comparison with control trees. Mean comparison results showed that urea at 12% treatment had the most effects on flower abscission and such urea 12% had lowest yield in all cultivars. This treatment increased fruit weight and fruit size in all cultivars in comparison to other treatment. Urea 12% had highest and NAA 15 and 20 ppm had lowest acidity in Cv.dixired. NAA at 15 and 20 ppm had the most effects on TSS in comparison other treatments in sun crest peach. The highest yield was obtained from control trees in two cultivars.