Ways of thinning the ovary of intensive plantings of apple trees of the Early Red One (Erovan) variety in the conditions of the Left-Bank Forest-Steppe of Ukraine

Abstract

In order to obtain high-quality fruits every year, trees must be kept in balance by regulating the strength of growth and fruit load. In intensive orchards, measures to regulate pollination and tree load are extremely important for obtaining stable high crops with good fruit quality. The purpose of the research was to study and recommend the optimal method of thinning the ovary for the winter ripening period of the Early Red One (Erovan) apple variety, which belongs to the Red Delicious group. The research was conducted in 2023 in the intensive apple orchard of the Kharkiv Fruit Company LLC, located in the Kharkiv region. Each variant of the experiment was carried out in triplicate. The size of the repetition was 5 accounting trees placed consecutively in a row. Various methods of thinning and their combination were used during the research. The experiment scheme included the following options: Darwin 220 rpm + Exilis 6.8 l/ha, Exilis 6.8 l/ha, ATS 15 l/ha + Exilis 6.8 l/ha. According to the results of our research, it was established that the smallest number of fruits on trees is 43.7 pcs. was obtained by mechanical thinning with a Darwin machine followed by thinning with Exilis. When only Exilis was used, trees had an average of 100.3 fruits at the time of harvest, which was 20% more than optimal. The application of the ATS+Exilis thinning option made it possible to obtain 68.7 fruits per tree. This value was only 8% less than the optimal one. The highest crop – 54.27 t/ha was provided by thinning only with Exilis 6.8 l/ha. It was established that the smallest number of fruits with a diameter of 70 mm was obtained for the same method of thinning – 77.7%. The maximum value of the analyzed indicator was 82.1% for trees that were thinned with the drug ATS with the subsequent use of the drug Exilis.