Effects of Benzyladenine and Naphthalene Acetic Acid Applications on Fruit Thinning and Quality of Some Apple Cultivars Grafted onto MM 106 Rootstocks

WOS: 000505765900013Fruit thinning is an essential practice to improve fruit size and quality, control alternate bearing and increase return bloom in the next season. Fruit thinning is performed by hand or by using some chemicals. In this study, the effect of chemical thinning, namely two doses of 5 and 10 ppm of Naphthalene Acetic Acid (NAA) or of 100 and 150 ppm of Benzyladenine (BA) on fruit thinning and some fruit quality traits Golden Delicious, Red Chief and Granny Smith apple cultivars grafted on MM 106 clone rootstock in 2015 was tested and compared with the effect of hand thinning. Chemical treatment was applied after three weeks of full bloom, while the hand thinning was made to be released a fruit per cluster on each branch in small fruit period after June-drops. The results showed that the highest fruit thinning ratio was found in the Granny Smith cultivars, with 5 ppm (93.80%) and 10 ppm (91.65%) of NAA, 100 ppm (89.88%) and 150 ppm 88.98%) of BA. It can be concluded that the applications of 10 ppm of NAA and 100 and 150 ppm of BA were found effective for fruit thinning and fruit quality. Furthermore, the hand thinning application increased the fruit weights more than all the chemical applications