Fruit growing
and viticulture of South Russia

Annotation

The article presents the results of experimental studies of the effect of the systemic application of a �Maxifol Mega� special agrochemical of specific action on the functional state and nutrition regime of apple plants in unstable environmental conditions. Aqueous solutions of the drug were used in fruit-bearing plantings of low-growing apple trees of the Idared, Prikubanskoe, Renet Kubansky varieties in the experimental production farm �Tsentralnoye� (Krasnodar) in 2019-2021. Methodological support of field and laboratory studies of plant samples (leaves, shoots) is generally accepted, recommended for experiments with fertilization of fruit crops. It was found as a result of the research that non-root apple tree treatments had a positive effect on the intensity of synthetic processes in plants under the conditions of the destabilizing effect of abiotic factors. The total chlorophyll content in the leaves was 5.6-23.0% higher than this indicator in the control variant at the stage of formation and growth of fruits (X-XI stages of organogenesis) in 2019 and 2020. The content of photosynthetic pigments did not exceed 3 mg/g of dry matter against the background of prolonged absence of precipitation and maximum air temperature values of 34.6�38.1 ºC in July and August. At the same time the indicator was higher by 15.0-18.4 % against the background of the application of non-root treatments of trees. The gross content of the main nutrients in the leaves mainly in the middle part of the shoot in 2020 and 2021 exceeded the value of the indicator in comparison with the control variant in June, July and August. The potassium content in the leaves of the middle part of the shoot was higher by 0.8-45.8 % depending on the variety against the background of moisture deficiency in August. The derived level of seasonal functional activity of the apple tree and the nutrition mode corresponds to a higher yield class against the background of the action of the �Maxifol Mega� drug in comparison with the yield in the control variant: the Prikubanskoe apple variety (1852 trees/ha) 24.4 and 28.1 t/ha; the Idared apple variety (2469 trees/ha) 38.5 and 44.2 t/ha; t he Renet Kubansky apple variety (1852 trees/ha) 34.8 and 29.9 t/ha.