Fruit growing
and viticulture of South Russia

Annotation

Due to recent climatic changes � a decrease in the amount of precipitation in the phenophase of berry growth and ripening, the issues of drought resistance of grapes, the selection of the most resistant varieties are relevant. The purpose of the work is to study the structural and functional changes of the leaves of various grape varieties under the influence of stressors of the summer period, to identify highly drought-resistant varieties for cultivation in the Anapo-Taman zone of the Krasnodar region. The objects of research are grape varieties of various ecological and geographical origin: Kristall (control) � Euro-Amuro-American origin; Krasnostop AZOS, Dostoynyi � Euro-American origin; Vostorg � Amuro-American origin; Zarif � Eastern origin; Aligote � Western European origin. Differences in the hydration of leaf tissues and the content of photosynthetic pigments associated with the formation of a protective response to meteorological conditions in the summer of 2019-2021 were found. The following features was found in the varieties Kristall, Krasnostop AZOS, Vostorg, Zarif, identified as highly resistant to summer stresses: the smallest decrease in the water content of leaf tissues (1.3-2.3 %), in contrast to the varieties Dostoynyi and Aligote (by 2.9 %); - a slight (by 7.4-9.1 cm2 ) decrease in leaf area, in contrast to the varieties Dostoynyi and Aligote (by 27.5-29.3 cm2 ); - the most stable content of the total chlorophylls during the summer growing season, a decrease in their content (by 0.22-0.36 mg/g wet weight) in in contrast to varieties Dostoynyi and Aligote, in which the decrease was 0.69-0.88 mg/g fresh weight; - the lowest values of chlorophylls/carotenoids are 2.0-2.8, in contrast to the varieties Dostoynyi, Aligote - 3.3 and 3.4, respectively. The grape varieties Kristall, Krasnostop AZOS, Vostorg, Zarif, according to physiological and biochemical parameters, proved to be highly drought-resistant for cultivation in the Anapa-Taman zone of the Krasnodar region and use in breeding.

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.

Annotation

Evaluation of grape resistance to low negative temperatures is relevant in connection with the increasing climate instability in the Anapo-Taman viticulture zone. An important metabolite associated with resistance to low temperatures is ascorbic acid. The purpose of this work is to conduct a comparative study of grape varieties of different ecological and geographical origin in terms of the dynamics of ascorbic acid content in the autumn-winter period and to identify varieties with increased resistance to low temperatures in terms of this indicator. The objects of research are grape varieties of various ecological and geographical origin: Kristall (control) � Euro-Amur-American origin; Krasnostop AZOS, Dostoynyi � Euro-American origin; Vostorg � Amur-American origin; Zarif � Eastern origin; Aligote � Western European origin. It was found that during t he autumn-winter period in the buds of grapes there was an accumulation of ascorbic acid. Its greatest increase was noted in the varieties Dostoynyi and Krasnostop AZOS � 3.6 and 3.9 times, respectively, in other studied varieties, this increase was 1.2-2.9 times. After artificial freezing, the least damage of cell membranes, determined by the accumulation of malondialdehyde (MDA), was noted in the Krasnostop AZOS variety � an increase in the content by 1.09 times. The varieties Kristall and Dostoynyi were next in terms of resistance � an increase in the level of MDA by 1.15 and 1.36 times, respectively. In other studied varieties, identified as unstable, this increase was 2.2-2.93 times. In varieties Krasnostop AZOS, Kristall, Dostoynyi after freezing, the content of AA increased � by 6.7-9.6%, i.e. ascorbic acid played the role of a low molecular weight antioxidant in suppressing the development of oxidative stress. According to the content and accumulation of ascorbic acid in the buds, the Krasnostop AZOS variety was identified out as the most resistant to extremely low temperatures. Next in terms of resistance were the varieties Dostoynyi, Kristall. The content of ascorbic acid in grape buds can be used as a diagnostic criterion in the selection of frost-resistant varieties for breeding purposes.