Fruit growing
and viticulture of South Russia
To improve the organic nutrition of a grape plant in in vitro culture, studies were conducted on the effect of sucrose on the development of test-tube plants. Despite the fact that sucrose is the most commonly used and sufficiently studied source of carbon in in vitro nutrient media, at this stage of the study, it was necessary to clarify and compare the response of specific model varieties to various concentrations of sucrose, and also to obtain, at the end of the experiment, a sufficient number of microplants for further stages of research. Two varieties with diametrically opposite characteristics of development in in vitro culture were taken for the study. The Sibirkovyi variety was chosen as one of the fastest growing and, accordingly, the fastest aging (in vitro culture) varieties, and Krasnostop Karpi is one of the slowest developing varieties in in vitro culture. In addition, these varieties also differ genetically. Sucrose concentrations from 0 to 40 g/L were used in the experiment. The varietal reaction of model varieties in the experiment with different concentrations of sucrose in the nutrient medium showed both general patterns and minor differences. For the Sibirkovyi variety, the optimal concentrations for the development of most indicators of microplants were in the range from 5 to 20 g/l, and for the Krasnostop Karpi variety 5-10 g/l. There was a clear tendency to decrease the root length index with a decrease in sucrose concentration below and an increase above 30.0 g/l in both varieties. The best indicators of development and preservation in a year were noted in the variant where sucrose was not used at all, the variant with the lowest concentration of sucrose, 5.0 g/l, was slightly inferior to it. At the same time, at high concentrations, despite the worse preservation, a slowdown in the growth processes of the shoot and its maturation in some plants were noted.
Many years of experience in studying the winter hardiness of fruit trees and the analysis of literary sources indicate the difficulty of identifying forms resistant to low temperatures of the winter-spring period in the conditions of southern Russia. Prolonged autumn, constant temperature jumps in the winter-spring period and significant differences in the years of both average and minimum and maximum temperatures make it difficult to isolate plants adaptive to the stressors of this period. In winter, biochemical processes take place in the tissues of fruit trees, many of which are much more intense in the conditions of a warm southern winter than in the conditions of cold winters in more northern regions, and therefore, standards and parameters are needed to determine winter hardiness, acceptable specifically to the conditions of the south. The winter development and hardiness of fruit trees is determined to a very large extent by how many nutrients they accumulate in preparation for winter, and to what extent these substances will turn into protective ones. All this makes it necessary to conduct a comprehensive assessment of plants using physiological, biochemical, anatomical and morphological studies involving artificial climate cameras. In our work, the quantitative determination of starch in perennial branches and young shoots of sour cherries allowed us to reveal its dynamics during the annual cycle of plant development. Cherry varieties that showed excellent and good resistance to low temperatures had a greater number of starch grains. With the help of artificial freezing and the field method of research, it was possible to isolate the resistance of sour cherry varieties to each component of winter hardiness. The most resistant to the complex of winter stresses from the studied forms in the field conditions of Ust-Labinsk district, where low winter temperatures of up to -27 ºC are observed, according to the results of field experiments, freezing in special chambers and according to starch accumulation, were following clone Molodezhnaya, and cherry varieties Griot Timiryazevsky, Timiryazevskaya pozdnyaya.
The search for an accelerated assessment of the resistance of grape varieties to extremely high temperatures (hyperthermia) is of particular relevance due to the increasing climate instability in the Anapo-Taman viticulture zone. The purpose of this work is to conduct a comparative assessment of the response of grape varieties to artificially induced high-temperature stress (hyperthermia) in terms of peroxidase activity, the content of proline, ascorbic acid, and to identify varieties with increased resistance to high temperatures. 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. Studied varieties respond to hyperthermia by stimulating the functioning of the antioxidant system, the protective effect of which is determined both by the activation of peroxidase and by the accumulation of proline, ascorbic acid. It was found that peroxidase played an important role in the suppression of oxidative stress in the variety Dostoynyi an increase in its activity by 5.09 times; unlike other varieties, in which an increase was noted by 1.08-1.97 times. In other varieties, the maintenance of redox balance is achieved by increasing the content of proline, ascorbic acid. Insufficient peroxidase activity under conditions of hyperthermia in varieties Kristall and Zarif was compensated by an increase in proline content by 2.65 and 7.64 times, respectively. It was presented that in the varieties Kristall and Dostoynyi, ascorbic acid showed its protective effect along with proline an increase in its content by 2.31 and 2.66 times, respectively. In the Zarif variety under stress conditions, an increase in ascorbic acid by 8.35 times was observed. It has been established that the varieties Zarif, Dostoynyi, Kristall, unlike other studied varieties, are more resistant to extremely high temperatures in the summer period.
Important aspects of the vital activity of the root Poncirus trifoliate Raf. the main rootstock for the genus Citrus under the conditions of the subtropics of the Caucasus Black Sea coast are considered. The root system is not only an organ of absorption, excretion and metabolism, but also the interaction of underground and aboveground organs. The study of the power and nature of the structure of the root system, the depth of its infiltration into the soil is of great practical importance for characterizing soil fertility. The growth pattern of the above-ground and root systems of mandarin grafted on P. trifoliata should be taken into account at determining the area of plant nutrition during bedding. The root system of seedlings of Unshiu mandarin variety at the age of 1-2 years is characterized by specific features: primary roots have very few root hairs, the functions of which are performed by mycorrosis, which explains the need for aeration and hydration of the roots. The bulk of the roots of Unshiu mandarin seedlings on the P. trifoliata rootstock is located at a depth of 0-20 cm, and a smaller part at a depth of 20-40 cm. Most often, the root is interpreted as an organ that receives water with elements of mineral nutrition. However, the study of root systems makes it possible to develop agrotechnical methods of influencing on plants. The absorptive activity of the citrus root is given special attention due to the absence of root hairs, which are replaced by mycorrhiza. Mycorrhiza is a complex symbiosis of trifoliate roots and fungal mycelium. Over the years of evolution, their interaction has become necessary for each other. Therefore, the improvement of the soil environment in the root habitat zone is favorable for the growth and generative processes of citrus plants.
The paper summarizes the results of studies on the effect of micro-fertilizer with water-soluble ferrum on the biological and economic indicators of grapevine. Foliar dressing with micro-fertilizer of Kunlean grapevine variety plants was carried out in the following vegetative stages: before flowering; the next two top-dressings 15 days after the previous one. Foliar dressing with micro-fertilizer with water-soluble ferrum has shown its biological effectiveness, having a positive effect on the formation of berries in bunches, contributing to an increase in their mass and quantity. Significantly higher bunch weight, compared with the control, have been proven for variants with fertilizing rates of 0.6 kg/ha and 0.8 kg/ha, which resulted in a significant increase in plantation yield capacity up to 18 %. The positive effect of the agrochemical with water-soluble ferrum also affected the quality of the harvest. The mass concentration of sugars increased (22.4-22.8 g/100 cm3 ) in variants with different fertilizer application rates compared to the control variant. These indicators in plants of Kunlean variety were standard for varietal conditions. A close linear relationship between the micro-fertilizer consumption rate and the yield capacity value is demonstrated by the approximation of the obtained experimental data, which confirms that with an increase in the micro-fertilizer consumption rate, the yield also increases. The positive effect of micro-fertilizers with consumption rates of 0.6 and 0.8 kg/ha on the increase of sugar content in berry juice is confirmed by a close polynomial relationship between these values. The use of micro-fertilizers did not have a significant role in the acidity of berry juice. The recommended rate of application of micro-fertilizer with water-soluble ferrum to obtain an increase in yield with improved quality properties is 0.6 kg/ha.