Effect of chemical and hand thinning on growth, yield and fruit quality of nectarine (Prunus persicaBatsch var.nucipersica)

A field experiment was conducted during 2009 and 2010 to study the influence of fruit thinning on growth, yield, proportion of different grades fruit and fruit quality of nectarine. The thinning treatments consisted of foliar spray of NAA at 20, 40 and 60 ppm, ethrel at 100, 200 and 300 ppm, thidiazuron at 10, 20 and 30 ppm 3 weeks after petal fall, selective mannual removal of fruits to the intensity of 10, 20 and 30 per cent at pea stage and unthinned control. The results revealed that both chemical and manual thinning significantly improved fruit size, weight and proportion of ‘A’ grade fruits. Among the chemical thinning treatments, application of 300 ppm ethrel judiciously thinned fruitlets (24.15 & 25.38%), improved size and weight (89.90 & 92.75 g/fruit) of fruits, proportion of ‘A’ and ‘B’ grades fruits without any adverse effect on total yield as compared to other chemical treatments. Trees sprayed with 60 ppm NAA attained highest shoot length, tree volume and leaf area. Ethrel at 300 ppm and NAA at 60 ppm significantly increased TSS (14.23 & 14.31%), total and reducing sugars as compared to control. The net return of Rs. 668 and 982 per tree during 2009 and 2010, respectively and fruit quality attributes were also better with 300 ppm ethrel treatment.