Fruit growing
and viticulture of South Russia
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.
Micropropagation is a promising direction for obtaining a healthy, genetically homogeneous grape planting material. The efficiency of reproduction is determined by many factors, including the acclimatization of plants to natural environmental conditions. The difficulty of transferring in vitro plants to non-sterile conditions is associated with a number of physiological and anatomical features of in vitro plants, among which the low level of photosynthetic processes is of particular importance. The influence of various concentrations of sucrose in the culture medium and additives, simulating environmental stresses on the rates of photosynthesis of grapes during acclimatization, was studied. The content of sucrose 10g/l in the culture medium was the most optimal for the formation of the photosynthetic apparatus. Both low and high sucrose content in the culture medium negatively affected the formation of pigments and the efficiency of photosynthetic processes. The introduction of PEG and NaCl into the nutrient medium led to a decrease in the total content of pigments, the quantum yield of photochemical reactions, but increased the expression of RUBISCO activase. The use of ABA as part of the culture medium had a positive effect on the formation of pigments in grape plants during acclimatization. The effects of weak stresses on the photosynthetic parameters of grapes in in vitro culture and during the acclimatization period are identical to the effects of drought and salinity under natural conditions. At the same time, these types of influence have a positive effect on adaptive anti-stress reactions that prevent plant damage under ex vitro conditions, which ultimately increases the level of growth processes and the yield of seedlings during micropropagation of grapes.
This work presents the data on study results of two irrigation algorithms for CabernetSauvignon grape variety in production conditions of the Livadia branch of FSUE PJSC Massandra in the South Coast of Crimea in 2019-2020. Experimental physiological algorithm provided for two water stresses to be carried out. The first short-term water stress was during the period of berry growth, t he second one during the stage of berry ripening. The depth of water stress during the stage of berry growth in predawn values of water potentials in leaves was determined in the range of 0.50.55 MPa. The depth of water stress during the stage of berry ripening was in the range of 0.450.5 MPa. Crop load of plants in experimental version was determined as higher than normal by 20 % compared to the optimal one. The control variant was a stress-free irrigation strategy against the background of optimal crop load. Basic tool to control water status of plants was a pressure chamber for measuring water potentials of leaves. Growing seasons of 2019-2020 were characterized by a significant rise of average monthly air temperatures compared to average long-term values and low annual precipitation amount: 357.0 and 410.6 mm, respectively. Such weather conditions have led to high evapotranspiration flow rate in grape plants. And yet, in the third decade of June, the plants of experimental variant experienced extreme water stress (0.50.55 MPa). Ripening of grapes in stress variant of irrigation also took place with a moisture deficit. Average values of leave water potentials in predawn hours were 0.45-0.50 MPa. As a result of the research, it was found that stressful irrigation strategy against the background of an increased crop load, compared with a stress-free one and an optimal crop load, allowed an increase in the mass concentration of sugars by 1.5 g /cm3 , in the content of total phenolic substances by 28.3 % and coloring agents by 33.3 %.
The planting of basic mother grape plantations is usually carried out on sandy massifs, which have a number of specific properties, both positive and negative. One of these properties is the heterogeneity of the soil cover. First of all, this is due to the fact that sands are subject to deflation to a greater extent than fixed soils. The soil horizon can be partially or completely destroyed, carried by the wind and deposited on top of other soils. Thus, a new soil cover is formed, but with other factors of soil formation. In this regard, when transferring healthy seedlings to the open ground, plants often die. To avoid this, the laying of elite mother plantations on the lands of sandy massifs must be carried out taking into account the characteristics of these lands, including taking into account soil heterogeneity. The soil cover was typified on the Nizhnekundryuchensk basic mother grape plantations, as a result of which all the diversity of soil conditions was reduced to 5 types (microzones). The purpose of our study is to determine the influence of soil and ground conditions on the growth and development of grape plants, as well as to substantiate the feasibility of using fertilizers. Observations were carried out from 2004 to 2022 on 5 grape varieties from different ecological and geographical groups. As a result, it was found that the development of basic plants strongly depends on the type of soil conditions, while the dynamics of bush preservation indicators after several years of growth was noted. At the first and second types, plant development was the best, quantitative and qualitative parameters of the harvested vine parameters were optimal. The use of fertilizers on the third type of soil and ground conditions allows to obtain a vine in quality not inferior to the vine obtained from the first type of conditions.
Apple varieties have different response to fertilization and changes of root nutrition conditions. For three years, we studied the effect of fertigation on the content of nutrients in the leaves and the yield capacity in apple cultivars: Lobo and Spartan, grafted on rootstock 62-396. Planting scheme is 4 x 1 m, trees were cultivated on meadow-chernozem and dark gray forest soils. The experiment on meadow-chernozem soil was carried in AO "Dubovoe" (Tambov region), the experimental plot on dark gray forest soil was located in OAO "Agronom-Sad" (Lipetsk region). Leaf samples for analysis were taken during periods of the highest demand for the appropriate nutrients: phosphorus at the end of May, nitrogen at the end of June, and potassium in mid-August. Soil samples were taken before orchard planting and in August of the 3rd year of the study. The negative impact of drip irrigation on the content of soil nutrients was noted: the acidity increased on the meadow-chernozem soil, in both types of soil the content of available nitrogen decreased, as well as phosphorus and potassium in the upper layers of the soil. The content of the main nutrients in the leaves under fertigation depended on the variety response to fertilization, as well as on the soil type: the Lobo variety had a higher content of the studied nutrients in the leaves when fertigated on dark gray forest soil. The Spartan variety had a higher content of nutrients in leaves during fertigation on meadow-chernozem soil. Fertigation had a significant effect on increasing the yield capacity of Lobo variety on dark gray forest soil, and the yield capacity of Spartan variety on meadow-chernozem soil.