Effect of Chemical Thinning on Some Qualitative and Quantitative Characteristics of Two Commercial Nectarine Cultivars

This research was carried out to evaluate the effects of chemical thinners urea and NAA on quantitative and qualitative characteristics of nectarine (cv. Independence and Nectared4) in Horticultural Research Station of Meshkinshar. Experiments were carried out randomized complete block with five treatments and three replications for three years. Application of urea (10, 12%) and NAA (15, 20 mg l-1) and control trees take place at full bloom stage. Characteristics such as flower abscission, fruit weight, fruit size, 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. Results showed that different concentrations of urea and NAA increased flower abscission, fruit weight, fruit size and decreased yield in two cultivars compared with the control trees. Application of urea at 12% had the most effect on flower abscission and produced the lowest yield in all cultivars. Urea at 12% increased fruit weight and fruit size in all cultivars compared with other treatments. Urea at 12% treatment decreased TSS content and increased acidity content in cv. Independence nectarine compared with other treatments. Results showed that application of urea 12% had the highest and control trees had the lowest flower abscission in nectarine cv. ‘Nectared4’. NAA at 15 and 20 mg l-1 and urea at 10% treatments had the highest TSS in ‘Nectared4’. The highest amount of yield was obtained from control trees in all cultivars.