The influence of thinning agent on base of 6-BA and NAA on productivity and fruit quality of „Gala Must” variety

Abstract

Chemical thinning of pome fruits is important measure for the profitable agricultural production of fruits. Chemical thinning provides a good yield potential for the following vegetation. Thinning the apple crop during the post bloom period is absolutely essential to ensure large fruit size, superior fruit quality, and reliable annual cropping. To evaluate the influence of thinning agent on base of 6-benzyladenine (6-BA) and naphthalene acetic acid (NAA) in reducing fruit set and quality in Gala Must apple trees. The experimental plot was founded in 2006 with trees of „knip boom” canopy type. The study subject of the experience was Gala Must apple variety grafted on M 9. The trees were trained as slender spindles. The distance of plantation is 3.5 x 1.2 m. The tested combination was 6-BA and NAA. The preparation was sprayed on the trees either one time, when the king fruit diameter was 10-15 mm. The research was conducted during the period of 2011 year. During the research, it was studied the number of blossom clusters before thinning degree, fruit at harvest time, yield, mean fruit weight, average fruit diameter, size classes based on their diameter and the number of pygmy fruits. It was established that, the good effect of thinning was noticed after single application of 100 ppm 6-BA + NAA 10 ppm. The combined treatment with 6-BA 100 ppm + NAA 10 ppm has a significant effect on yield, mean fruit weight and positively influenced fruit size, the distribution of apples in size classes.