The present study substantiates the use of biologicals for limiting fungal, including vascular, infections in the production of grafted grape seedlings. The eff ects of antimicrobial pre-planting treatment of cuttings and grafts on the number and structure of micromycetes in the scion and rootstock of seedlings is revealed. The total activity of biologicals in suppressing fungal and bacterial microfl ora is analyzed; a strong and prolonged biocidal eff ect of Phytolavin SC and Trichodermin L is established. The studies also examine changes in the taxonomic composition of the hyphomycete complex under treatment conditions. In the production of cuttings, all biologicals show high effi ciency in suppressing Botrytis cinerea Fr., as well as Phomopsis viticola Sacc. vascular pathogen. The production of grafts using Chinosol reveals insuffi cient suppression of gray mold and excoriosis. B. cinerea and P. viticola occupy 10.2–11.8 and 0.2–0.7 % of the total number of hyphomycetes, respectively; in the remaining experimental options, complete suppression of these mycopathogens is noted. In post-excavation analyses of seedlings treated with Chinosol SP and Pharmaiodine GS, fusarium infection is detected annually on both the scion and rootstock parts; excoriosis infection is consistently detected on the rootstock part and once on the scion. The biological effi ciency of this complex treatment in reducing the infection of plants with tracheomycosis is assessed. The promising Phytolavin SC 0.4 % and Trichodermin L 0.5 % biologicals are the most effi cient in suppressing tracheomycotic infection. They have a fairly high fungicidal activity and adaptive regulatory eff ect on the overall structure of micromycetes without sharp fl uctuations in individual groups of fungi.

Intensive horticulture implies the use of mineral fertilizers to maintain the desired yield and productivity of crops. Regular application of mineral fertilizers in high doses may have a detrimental impact on soil properties. This problem can be mitigated using microbiological fertilizers, capable of increasing the content of available nutrients. In this work, we investigate the possibility of applying a formulation based a microbial consortium (MC) of several species of bacteria and yeast. Today, such formulations are widely and successfully used in agriculture. Our aim was to study the eff ectiveness of MC for fertigation in an intensive apple orchard. The fertigation modes were the single-factor application of MC and its combination with reduced doses of mineral fertilizers, both separately and in combination. The research was conducted in 2022-2024; the contents of essential nutrients in the soil and leaves, as well as the apple tree yield, were studied. The single- factor application of MC (15 L/ha) and its separate application (9 L/ha) with mineral fertilizers N_9.8P_5.4K_18.0 had the greatest eff ect on the content of easily hydrolyzable nitrogen in the soil. In the former case (MC only), the nitrogen content of 160.0–262.2 mg/kg was achieved (in 2024, the nitrogen content in the soil was noticeably lower than in 2022–2023, although being maximal in this variant). In the latter case (MC + mineral fertilizers), the content of easily hydrolyzable nitrogen was 148.3–218.8 mg/kg. The content of mobile phosphorus in the soil in all variants with the application of MС in various combinations (159.9–287.9 mg/kg) was equal to that in the variant with the application of the maximum rate of mineral fertilizers (135.7–303.8 mg/kg). The maximum content of exchangeable potassium in the soil was observed under a separate application of MC + N_9.8P_5.4K_18.0 (194.0–203.0 mg/kg). The use of MC contributed to an increase in soil pH (from 5.21 to 5.87 pH units) under its single-factor application. The highest content of total nitrogen in the leaves was observed with the application of the maximum rate of mineral fertilizers (1.93 % dry matter), while the single-factor application of MC (1.84% dry matter) led to the same level of the nutrient within the limits of experimental error. The phosphorus content in leaves depended signifi cantly on the application of mineral fertilizers (0.27–0.32 % dry matter), although the use of MC also contributed to an increase in the phosphorus concentration in some years. The potassium content in leaves under a single-factor application of MC (1.26–1.99 % dry matter) was higher than with the use of the maximum rate of mineral fertilizers (1.15–1.65 % dry matter), while the separate use of MC + N_9.8P_5.4K_18.0 contributed to the potassium content at the same level (1.12–1.76 % dry matter). The maximum total yield (33.5 t/ha) was obtained with a single-factor application of MC. The separate application of MC + N_9.8P_5.4K_18.0 did not lead to a signifi cant increase in the yield (30.5 t/ha) compared to the variant where the maximum rate of mineral fertilizers was used (31.9 t/ha). The greatest eff ect of MC use was observed during its single-factor application and when applied separately from mineral fertilizers.

The cultivated apple is a traditional crop for Abkhazia. However, the humid subtropical climate here promotes the intensive development of fruit diseases, such as scab (caused by Venturia inaequalis (Cooke) G. Winter) and moniliosis (caused by Monilinia fructigena (Pers.) Honey). Research efforts today are aimed at searching for formulations capable of enhancing the natural immunity of plants against these diseases. In this work, we assess the possibility of extending the protection system against apple scab and monilial rot by including a single treatment with growth regulators during the budding phase. The studies were conducted in 2022–2024 in Golden Rangers apple tree plantations in the Gulrypsh district of the Republic of Abkhazia using a generally accepted methodology. The immune-stimulating effect of the Zerebra agro©, Biosil©, and Stimmunol EF© growth regulators against fruit scab was observed in the second and third years of application. With regard to monilial rot, the effect was observed in the third year of application. Yantarin BAU© demonstrated an increased biological effectiveness against scab and moniliosis already after the first application. A single application of the Zerebra agro©, Biosil©, Stimmunol EF©, and Yantarin BAU© growth regulators during the budding period did not increase the apple yield. Energiya-M, KRP© did not exhibit an immune-stimulating effect against either scab or moniliosis. However, a single treatment of the plants with this preparation during the budding period resulted in a 23.4 % increase in the apple yield compared to the control.

This study evaluates the storage potential of the Moldova and Shokoladnyi table grape varieties from the commercial vineyards of the Massandra JSC. The study was conducted in 2023–2024. The implementation of an environmentally friendly storage alternative as a means of improving storage technology is investigated. Experiments were performed in a refrigeration chamber. The control group was treated with SO₂, while the experimental group was exposed to a bactericidal ultraviolet (UV) emitter. The application of UV radiation resulted in a lower mass concentration of sugars in the studied grape varieties at the end of storage, being on average 6.3 % lower than those in the control varieties. Conversely, the overall sensory evaluation score was 12.8 % higher. The use of UV treatment contributed to a reduction in the activity of monophenol monooxygenase, which was on average 21.6 % lower relative to the control. Furthermore, the extent of grape bunch spoilage was on average 12.8 % lower, and the percentage of disease development was 14.8 % lower than in the control. The studied samples exhibited minimal values of weight loss in the bunches, which were 7.8 % lower compared to the control. The results of mathematical processing indicate a strong and significant correlation between the weight loss of the average grape bunch and the degree of infection by mold rot; the share of their influence on weight loss averaged 79 %. Upon completion of long-term storage, the following pathogenic microorganisms were isolated from the grapes of the studied batches: Penicillium expansum L., Penicillium discolor F. & S., Penicillium digitatum (Pers) S., Penicillium spp. L., Penicillium notatum T., Aspergillus niger T., Aspergillus oryzae C., and Rhizopus spp. E. UV radiation treatment shows promise for maintaining the primary commercial quality parameters of grape berries and suppressing the activity of pathogenic microorganisms during long-term storage.

When developing new apple varieties (Malus domestica Borkh.), selection breeders should take into account not only the specifi c features of the cultivation area but also the desired set of economically valuable characteristics, including fruit storability with minimal quality loss. Apple fruits should meet a number of essential criteria, important to both producers and consumers. New genotypes should maximally conform to the characteristics of a commercial “model” variety developed and adapted to particular weather conditions. The parameters of storability under low storage temperatures should be accompanied by minimal quality loss and a high resistance to physiological disorders and microbiological diseases during storage. This study was aimed at identifying the most promising apple varieties in terms of an integrated set of storability criteria using “simulation” and “optimal” variety models. A simulation model of an “ideal” apple variety was developed, taking into account the criteria of fruit storability and durability during storage. On this basis, an “optimal” apple variety model for the central part of the Russian Federation (Central Region) was developed. The “ideal” and “optimal” models were described using 16 post-harvest criteria for 35 apple varieties studied over a 20-year period. The data were processed using a hierarchical clustering algorithm (HCA) with the Ward method and factor analysis with a multivariate principal component analysis to identify the most promising apple genotypes based on their maximum similarity to the model in terms of a set of storability traits and fruit resistance to physiological disorders and microbiological diseases during refrigeration at various temperatures. The degree of similarity between the developed models and the studied genotypes was determined based on the Euclidean distance. The Svezhest and Orlovsky Partizan varieties were closest to the “ideal” model. The criteria for the Svezhest variety were used as the basis for developing an “optimal” model. The Yubiley Moskvy, Orlovsky Partizan, Start, and Turgenevskoye varieties were closest to the “optimal” model.