Influence of the NAA product on the premature Gala Mast fruits drop and quality indices

Abstract

The aim is to study the effectiveness of applying grow regulator Obsthormon 24a (NAA) to ‘Gala Mast’ cultivar in different doses and treatment periods to maintain the physiological balance in the plant and keep the fruit in the crown as much as possible at the time of fruit harvesting. To achieve the stated goal, the following variants were studied: (1) the control (trees sprayed with water only); (2) NAA 15 ppm; (3) NAA 22.5 ppm; (4) NAA 30 ppm; (5) NAA 37.5 ppm; (6) NAA 15+15 ppm; (7) NAA 15+22.5 ppm. To prevent premature fruit drop, to treat with NAA 30 ppm 15 days before harvest, or in two doses of 15 ppm. The first treatment to be applied in the first decade of July, when the differentiation of fruit buds on the apple starts, and the next one 15 days before harvest.