Eficiența răririi chimice în diferită doză de tratare la soiul Gala Must cu produse pe bază de NAD, ANA și BA

Abstract

The researches were carried out in the period 2014-2017 in the intensive apple orchard of the enterprise „Codru ST” Ltd. founded in 2006. The efficiency of chemical fruit thinning was studied in Gala Must variety grafted on M9 rootstock. The following active substances were applied: 1. naphthalene-acetamide NAD (Geramid-New), 2. naphthylacetic acid ANA (Dirager) and 3. benzyladenine BA (Gerba 4LG), using different doses and thinning periods. During the research the following indicators were studied: the number and average weight of fruits, the yield per tree and per unit area, and the average fruit diameter. On average, over the years 2014-2017, the highest number of fruits in the crown of apple trees was obtained using the growth regulators Dirager (131.2 pcs/tree) and Geramid-New (128 pcs/tree), while the variants treated with Gerba 4LG recorded the highest yield per tree 18.01 kg/tree and the highest average fruit diameter 74.1 mm. The average fruit weight as a quality indicator varied greatly over the studied years. This indicator largely correlated with the number of fruits in the tree crown and weather conditions in the year of reference. It was established that the treatments with Geramid-New in a dose of 1.2 l/ha when 80% of the petals have fallen + 2-3 days, with Dirager in a dose of 0.3 l/ha when the diameter of the central fruit is 8-9 mm and with Gerba 4LG in a dose of 2.5 l/ha when the fruit diameter is 10-15 mm have a significant effect on the studied indicators.