Fruit growing
and viticulture of South Russia
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 34.638.1 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.
In this work, organic fertilizer OFA with its effect on the yield, quality of grapes and base wines is examined. The aim of the research was to establish the effect of foliar dressing with OFA organic fertilizer at a hectare rate of 1 l/200 l of water per yield, quality of Cabernet-Sauvignon grapes, as well as physicochemical parameters of base wines. The studies were carried out in FSUE PJSC Massandra, Southern Coast of Crimea in a grafted, fruit-bearing vineyard, with a high-trunk bush training spiral cordon AZOS-1, planting pattern 3.0 x 1.25 m. The control is without treatment. Foliar treatment was carried out three times in phenological growth stages: Before flowering, Two weeks after flowering, Formation and growing of berries. Records and observations were carried out according to methods generally accepted in viticulture. Physicochemical profiles were determined using liquid chromatography (Shimadzu LC20 Prominence). As a result of the research, it was found that foliar application of peat-based organic fertilizer in the vineyard is one of the most effective ways to increase the bunch weight, yield per bush and cropping capacity. This was reflected in an increase in the bunch weight by 28.3%, as well as yield per bush and cropping capacity by 38.1% and 37.5%, respectively. A positive response of plants on foliar dressing, reflected in an increase in potential photochemical activity of leaves by 11.6%, was established. At the same time, the content of sugars in berry juice decreased by 2.5 g/100 cm3 , while the values of titratable acids increased by 1.9 g/dm3 . The prevalence in acidic profile of malic acid over tartaric acid by 31.0% and 11.1% was established in experimental and control variants of base wines, respectively. It is noted that using of organic fertilizer OFA ensures obtaining of high quality base wines. Tasting assessment of base wines was 7.9 points, corresponding to the control sample assessment
To develop protective measures, it is necessary to identify the most dangerous and new harmful objects, as well as to select drugs with high efficiency. However, it is not always possible to assess the effectiveness of inhibition of a particular fungus species by chemical preparations; in addition, many phytopathogens can acquire a certain level of resistance to fungicides. For this reason, it becomes necessary to study the effectiveness of drugs against individual species using laboratory methods using pure cultures of fungi. The in vitro method makes it possible to evaluate the effectiveness of chemical preparations against pathogens in a fairly short time. However, there is the problem of the lack of a standardized method for assessing antifungal activity against economically important pathogens of agricultural crops. The studies were performed by two methods depending on the method of introducing the drug into the medium: by agar stab technique with a uniform introduction of the drug onto the surface of the nutrient medium and by inoculation the conidial suspension of the pathogen with a microbiological spatula when the drug is introduced on paper disks. The antifungal activity of chemicals against the fungus Alternaria alternata, the causative agent of apple fruit rot, varied in a wide range from no effect to strong, but in most variants of the experiment it was medium and the data obtained by the two methods of study were comparable. Comparison of these two methods showed a different degree of reproducibility of the results. So the most stable and repeatable results were given by the method with a uniform application of the working concentration of the drug to the surface of the nutrient medium and sowing by injection. In our study, the disk-diffusion method turned out to be more laborious, and the effects obtained by this method were not always characterized by an unambiguous interpretation and differed in repetitions, in comparison with the method in which the fungicide was applied directly to the agar plate, and the sowing was carried out by agar stab technique. Further optimization and standardization of this method is needed, including the amount of fungal inoculum applied and the thickness and evenness of the agar plate.
The analysis of the epiphytic microflora of the leaves of wild grapes growing in the forest near the river and the mountain slope of the Crimean district was carried out. The research was carried out in 2020-2021. The number and structure of complexes of micromycetes associated with grape leaves were determined by swab test method of diluted suspension on a dense nutrient medium (PSA). The structure of the complex of micromycetes associated with leaves in grape plants growing in the floodplain of the river in the spring period was characterized by an abundance of yeast (61,3%), and in plants growing in the forest, mycelial, yeast and yeast-like fungi were approximately in equal proportions. By the beginning of autumn, mycelial fungi dominated in the structure of micromycetes of both ecotopes. The total number of microscopic fungi on the leaf surface of wild grapes changed under the influence of environmental conditions. The leaf apparatus of grape plants from the forest had a smaller number of micromycetes (on average for 2 years ranged from 1315.2...5094.7 thous. CFU /1gr dry matter), compared with plants growing in the floodplain of the river (on average for 2 years ranged from 5116.1 to 9279.7 thous. CFU /1gr dry matter). Thus, the total number of microflorae of grape leaves is affected by the humidity regime of the air and soil. Species of the genus Cladosporium sp. 44.4 % (May), Phomopsis sp. 65.8-78.2 % (July-September) were distinguished as dominant on the leaves of wild grapes of the forest area during the growing season. In the sample growing in the floodplain of the river, the dominant ones were: Phomopsis sp. (54.8 % in May; 82.4 % in September) and Cladosporium sp. (53.6 % in June; 35.3 % in July).
The walnut (Juglans regia L.), belonging to the Juglandaceae family, is widely cultivated in all moderate and subtropical regions. In recent years, damage to walnuts by bacterial blight has been noted. This disease, known as bacteriosis, is caused by the bacterium Xanthomonas jglandis (Pierce) Dowson. Bacteriosis causes the most severe damage in spring in wet and warm weather, which leads to a decrease in yield and quality of fruits. The purpose of the study is to identify the most resistant genotypes for use in breeding based on a long-term field assessment of resistance to bacteriosis of walnut hybrid forms. The objects of study are 21 promising hybrid forms of walnuts bred at the FSBSI NCFSCHVW. Control variant is variety Rodina. The garden was planted in 2014, the layout was 5 × 4 m. The studies were carried out on a natural agrobackground in a breeding garden in 2019-2021, in the central part of the Kuban horticulture zone of the Krasnodar region, on the basis of ZAO OPH Tsentralnoye of FSBSI NCFSCHVW Krasnodar. R&D was carried out according to generally accepted programs and methods. The degree of damage of walnut hybrid forms by bacteriosis was assessed using a scale from 0 to 5 points. It was revealed that bacteriosis annually damages walnut plants, and the degree of disease damage depends on the prevailing weather conditions. It was found that the most favorable years for the development of infection were 2019-2020. According to long-term data, hybrid forms of walnut resistant to bacteriosis have been identified: 17-2-35, 17-3-10, 17-3-12, 17-3-41, 17-3-44, 17-3-48, 17- 3-24, 17-3-27, 17-3-29, the degree of damage over the years of study of which varied from 1.1 to 2.0 points, the maximum did not exceed 2.0 points. Most of the hybrids isolated for resistance to bacteriosis were obtained from the Dachny family free pollination of the NCFSCHVW breeding, which has in its origin the Central Asian variety Ideal. The isolated forms of walnut are promising for further breeding for resistance to Xanthomonas jglandis (Pierce) Dowson.