Fruit thinning by using NAA agent on the Jonagored apple variety

Abstract

The experimental plot is placed in the orchard “Dacfruct” Ltd. founded in 2006 with trees of a „knip boom” canopy type. The study subject of the experience was Jonagored apple variety grafted on M 9 weak vigor rootstock. The trees were trained as slender spindles. The distance of plantation is 3.5 x 1.2 m. The research was conducted during the period of 2011 year. The aim of this study was to evaluate the effectiveness of thinning agent in reducing fruit set in Jonagored apple trees. The tested agents were NAA, which was sprayed at two different times during the thinning period. During the research, it was studied the yield, mean fruit weight, average fruit diameter, the number of first class fruits. It was established that, in the 2011 year, the two treatments have a significant effect on yield, mean fruit weight and on the distribution of apples in size classes.