Objective. To study the role of phytopathogenic bacteria in the pathology of bioenergy crops. Methods. Classical microbiological, phytopathological, biochemical, statistical methods were used in the study, meteorological conditions during the years of the researches were taken into account. Results. The experimental and review article confirms the involvement of the bacteriosis pathogens Pectobacterium carotovora subsp. carоtovora (causative agent of soft bacterial rot of acorns), Lelliottia nimipressuralis (causative agent of bacterial dropsy), Lonsdalea quercina (causative agent of acorn “drip disease”), Erwinia rhapontici (causative agent of dry rot of branches and trunks) and Pseudomonas fluorescens (causative agent of cancer ulcer disease) in the weakening and massive drying of common oak trees in Ukraine. The causative agent of bacteriosis of hanging birch Betula pendula is a phytopathogenic polybiotrophic bacterium L. nimipressuralis, which also causes water dropsy of coniferous and deciduous forest woody plants. A direct dependence of the spread of tuberculosis on the proportion of ash (Fraxinus excelsior) in the structure of plantations of different age groups was established. In the region of research, tuberculosis reaches epiphytosis on sprouting trees, especially the young ones. Outbreaks of ash tuberculosis in the study area were observed in the years when the moisture availability index was the lowest. Conclusions. The results of the bacterial pathology of bioenergy woody plants (birch, ash, poplar, oak, willow) study indicate an evolutionary negative process that leads to a significant reduction in harvest or death of trees.

Objective. To analyse the scientific literature on the role and impact of the artificially formed microbiome on the processes of carbon transformation in agroecosystems. Methods. Collection, analysis and synthesis. Results. The carbon cycle is a fundamental process that determines the balance of the element in the biosphere and affects the climate stability of the planet. Soil is one of the main carbon reservoirs, containing more carbon than the atmosphere and vegetation combined. In this context, the soil microbiome — a collection of bacteria, archaea, steptomycetes, micromycetes and other organisms that inhabit the soil medium, including the plant rhizosphere — plays a key role in the transformation, storage and mobilisation of carbon. Microorganisms catalyse the humification of organic matter, which results in the formation of stable forms of soil carbon that can remain in the soil for hundreds or even thousands of years. For example, by enhancing the formation of microbial biomass, about 2–4 tonnes of organic carbon per hectare can be stabilised annually in chernozem soils. Soil microbiomes artificially created using biotechnological methods open up new opportunities for managing carbon transformation and decreasing climate change consequences. Conclusions. Artificially created soil microbiomes are a promising tool for managing the carbon cycle and decreasing the effects of global climate change consequences. The large-scale implementation of biotechnological measures aimed at changing the composition and functioning of the soil microbiome will not only improve soil quality, but also conserve organic carbon and reduce greenhouse gas emissions. Further researches and developments in this area are necessary to fulfil the potential of artificially created microbiomes in sustainable agriculture.

Objective. To study the effectiveness of winter wheat seed treatment with chemical disinfectants and a complex preparation based on Azotobacter vinelandii 7 AI, A. chroococcum 8 AI and Bacillus megaterium 39 AI. Methods. The microorganisms that form the basis of the complex biological product were tested for compatibility with fungicides in the laboratory. For this purpose, the bacteria were incubated with a chemical disinfectant and their titer was subsequently determined. The effectiveness of the microbial preparation alone and in combination with chemical fungicides was tested in the fields of the Skvyra Experimental Station of Organic Production of the Institute of Agroecology and Environmental Management of the National Academy of Agrarian Sciences. All records, observations of the growth and development of plants in crops, morphological parameters and analyses in the experiment were carried out in accordance with generally accepted methods. Results. While testing the compatibility of microorganisms with agrochemicals, it was found that the fungicide Weibrans Trio (sedaxane 25 g/l, fludioxonil 25 g/l, tebuconazole 10 g/l) provided a slight decrease in the number of bacteria tested (up to 10 %). The fungicide Avicenna (tebuconazole 50 g/l, prochloraz 250 g/l, cresoxim-methyl 50 g/l) led to a critical reduction in the titer of bacteria, especially representatives of the genus Azotobacter. The fungicide Acanto Plus (picoxystrobin 200 g/l, ciproconazole 80 g/l) had a slight effect on the number of bacteria studied over time. The complex treatment of winter wheat seeds, even in the mixture of the microbial preparation with Weibrans Trio and Acanto Plus fungicides, respectively, had a positive effect on the growth and development of wheat plants, increasing the yield of the crop. Conclusions. The results obtained indicate the effectiveness of the use of a new complex microbial preparation in the cultivation of winter wheat. The negative effect of the fungicide Avicenna on the components of the biological product when used in the same tank mixture for seed treatment was established. The combined use of the microbial preparation with the fungicides Weibrans Trio and Acanto Plus in the technology of winter wheat cultivation is acceptable.

Objective. Study of germanium and zinc carboxylates influence in the inoculation suspension of nodule bacteria for pre-sowing seed processing on the formation and functioning of soybean symbiotic systems — Bradyrhizobium japonicum under salinity conditions. Methods. Microbiological, physiological, statistical. B. japonicum strain PC08 and soybean variety Samorodok were involved in the research. The nodulation activity of rhizobia (number and weight of nodules on plant roots), plant weight (aerial parts and roots) in the phases of budding, blooming and bean formation, as well as indicators of soybean grain productivity were studied. The nitrogen-fixing activity of the symbiotic system was determined by the acetylene-restoring method using an Agilent Technologies 6850 chromatograph (USA). Results. It was found that the introduction of zinc nanocarboxylate into the suspension of nodule bacteria immediately before seed inoculation inhibited the formation and functioning of the soybean – B. japonicum symbiotic system, regardless the presence of sodium chloride in the plant growing substrate. The addition of germanium nanocarboxylate favourably influenced the interaction of soybean with nodule bacteria under salinity during the growing season, increasing the number and weight of nodules by 7–35 % and 5–33 %, respectively, and nitrogen fixation activity by 3 % to 48 %, but did not have a prolonged positive effect on the vegetative mass of plants. It was shown that on a salt-free background, the use of zinc led to a decrease in grain productivity of plants, in particular, grain weight per plant by 15 % and weight of 1000 grains by 8 %. Under salinity conditions, the compounds of both nanometals provided a slight increase in the weight of 1000 grains, with Ge contributing to a 13 % increase in the weight of grain per plant, and zinc causing a 12 % decrease in the number of beans per plant. Conclusions. The possibility of using zinc compounds under the conditions of symbiosis formation requires additional complex researches, which would include, in particular, the selection of optimal concentrations and forms of preparations or bacterial strains tolerant to this element. The revealed positive effect of germanium nanocarboxylate on the background of sodium chloride requires further research in order to use it in the development of the ways to increase the productivity of soybean – B. japonicum symbiosis under salinity conditions.

Objective. To research the ability of fungi of the genus Penicillium, isolated from the histosphere of soybean plants, release phosphorus from mineral and organic phosphates, study their effect on the general phosphorus content in plant shoots. Methods. Microbiological (cultivation of the tested fungi on Pikovska’s medium and its modifications, Czapek-Dox agar with tricalcium phosphate or phenolphthalein phosphate, wort agar), vegetation experiment (content determination of general phosphorus in the aboveground mass of soybean plants), statistical. Results. The use of three insoluble phosphates in Pikovska medium showed that the tested fungi dissolve to varying degrees Са3(РО4)2 and are unable to dissolve AlPO4 and FePO4. On the seventh day of cultivation, clearly visible zones of enlightenment were formed around the colonies of P. funiculosum 20312 and P. variabile 20173, with phosphate dissolution indexes of 1.17 and 1.18, respectively. When cultivating fungi on Pikovska medium with the addition of bromophenol blue dye in P. funiculosum 20312 and P. variabile 20173, the medium quickly changed colour from green to yellow, indicating the diffusion of organic acids produced by the fungi into the agar. Starting from the twelfth day of the experiment, the environment around the colonies of fungi P. glauco-lanosum 20401 also acquired a rich yellow colour and the halo zones formation was observed. The presence of phosphatase activity was demonstrated for all the tested fungi. The tested strains of fungi had a positive effect on the general phosphorus content in the dry matter of soybean shoots, this indicator increased notably in the variant with the use of P. funiculosum 20312 — 0.751 % against 0.643 % in the control variant. Conclusions. The tested fungi of the genus Penicillium, isolated from surface-sterilised roots of soybean plants, are capable of releasing phosphorus by dissolving inorganic and mineralising organic phosphates, and have a positive effect on the content of general phosphorus in soybean shoots.

Objective. Comparative assessment of vegetable crop varieties by the level of resistance to the main biotic factors in the context of plant protection system, with an emphasis on the implementation of integrated approaches to reduce pesticide load. Methods. The research was based on the example of six genotypes of white cabbage, which were selected for testing in the natural and climatic conditions of the Right-Bank Forest-Steppe of Ukraine. The main biotic factors considered in the research were alternariosis (Alternaria spp.), peronosporosis (Peronospora parasitica), bacteriosis (Xanthomonas campestris), as well as typical phytophages — cabbage scoop (Mamestra brassicae), cabbage moth (Plutella xylostella) and cruciferous flea (Phyllotreta spp.). Resistance was assessed using a five-point damage scale; for general interpretation of the results, descriptive statistical analysis was performed, taking into account the variation of indicators and correlations. The degree of damage was recorded in the phase of technical ripeness, using field observations during two growing seasons (2023–2024). The results are presented in the form of a summary table and two comparative graphs illustrating the variability of varietal resistance to diseases and pests. Results. The most resistant to a complex of biotic factors (phytopathogens and pests) were the varieties Slava 1305 and Amager 611, which showed the lowest scores for both disease and pest damage. Zenon F1 was resistant mainly to bacterial diseases. On the other hand, hybrids Transfer and Parel F1 required additional agrochemical protection due to the high degree of damage. Conclusions. The results obtained indicate the effectiveness of statistical methods in identifying resistant varieties that can be the basis for integrated plant protection, as well as a source of valuable genetic material for further selection program. The use of varieties with hereditary tolerance can theoretically reduce the number of pesticide treatments by up to 30%, by reducing the average damage score by 2–3 points from (4–5 to 1–2), which is consistent with evaluations in studies on integrated plant protection. The use of such approaches is relevant in the strategies of agricultural production adaptation to stressful environmental conditions.

Objective. To summarise the available data on new pathogens of blackleg and soft rot of potato tubers and analyse the risks of their spread. Methods. General scientific: comparison, generalisation, system analysis. The material for the analytical research was based on data from the European and Mediterranean Plant Protection Organisations (EPPO), phytosanitary services of different countries and scientific literature. Results. The bacteria of the genus Dickeya, which were separated in 2005 from the genus Pectobacterium, are pathogens of potato diseases with the common names “blackleg of potato stems” and “soft rot of tubers”. The overview of changes in the classification of bacteria, the isolation of new species of the genus Dickeya, as well as the spread of new pathogens of the disease blackleg and soft rot of potatoes are provided. Numerous researches have shown that D. dianthicola and D. solani have become the dominant pathogens of potato blackleg in the Netherlands, Switzerland, Germany, Belgium, and Poland, from where they spread to different countries with potato seed material within a short period of time. The most important factor in the likelihood of a disease outbreak in a field is the level of seed tubers infection. The speed of the disease and the extent of its spread depend on the humidity and temperature of the growing season, as well as on the field microrelief. Conclusions. The likelihood of adaptation and spread of Dickeya spp. in Ukraine, under the conditions of free international trade in potato seed and ornamental plants, is very high, especially for areas of traditional potato growing and irrigated agriculture. Risks of disease spread are increasing due to the lack of phytosanitary control by the state. The search for ways to prevent and contain bacterial diseases of potatoes is relevant in the current conditions for the Ukrainian potato producers: climate change and the need for increased irrigation, lack of confidence in the quality of seed material, and the lack of chemical plant protection products against bacteriosis. Biological control of bacterial pathogens, in particular blackleg and soft rot of potatoes, currently seems to be the most realistic way to combat the disease, which causes huge annual economic losses to producers.

Alfalfa poses challenges for ensiling because of its elevated protein levels, low amounts of water-soluble carbohydrates, low dry matter content, and high buffering capacity. As a result, there has been a recent push to improve silage production using additives. In recent years, silage additives have been employed to enhance the quality of alfalfa silage. Bacterial additives are employed to enhance the quality of crop silage, with a particular emphasis on hay silage. A primary objective of incorporating lactic acid bacteria into silage is to inhibit the proliferation of undesirable microorganisms, including Clostridium and Enterobacteriaceae. This is achieved by swiftly elevating the hydrogen ion concentration to a threshold that is inhospitable for the growth of these detrimental bacteria. Recent insights into the functions of bacterial additives in crop silage suggest significant potential for enhancing silage, not just as a fermented feed, but also to deliver probiotic substances that can benefit animal health. This article provides a comprehensive overview of the silage preparation process and critically assesses a range of studies concerning the quality of silage, as well as the impact of bacterial additives on alfalfa silage. The quality of silage can be enhanced by incorporating different bacterial inoculants, which help during fermentation, storage, and feeding by improving fermentation processes, encouraging beneficial microbial diversity, and inhibiting harmful microorganisms. Alfalfa is the most important forage, and microbial additives can enhance its silage preparation in a cost-effective and environmentally friendly way.

Objective. Evaluate root nodule formation, nitrogen fixation rates and lupine growth under seed inoculation with the microbial compositions of lupine and fodder galega nodule bacteria as well as to estimate lupine yield components. Methods. Yellow lupine (Lupinus luteus L.) cv. Kruglyk was grown in small-scale field experiments. Lupine seeds were inoculated with Bradyrhizobium lupini strain 359a (rhizobia nodulating lupine) mixed with Neorhizobium galegae strains 0702, 0703, or MC-1 (rhizobia nodulating fodder galega). The number and weight of nodules as well as shoot weight at both the six-leaf (BH31) and budding (BH51) stages were determined. The number and weight of seeds per plant and 1000-seed weight were also examined. The rate of nitrogen fixation was measured by acetylene reduction assay. Results. The binary consortia of lupine and fodder galega nodule bacteria differed from each other in their effects on the establishment of the symbiosis of lupine with B. lupini and on the aboveground growth of plants. The extent of effects of the consortia depended on their composition. The combined inoculation with B. lupini 359a and N. galegae 0702 led to an increase in the number and weight of root nodules at the six-leaf growth stage as compared to control (inoculation with 359a only). At the same time the mentioned mixed culture promoted the aboveground growth of lupine during the period of experiments. The application of B. lupini strain 359a in combination with N. galegae strain MC-1 resulted in an increase in the number of root nodules and low nitrogen fixation rates. But besides that, an insignificant stimulating effect on lupine shoot weight was observed for a binary consortium consisting of 359a and MC-1. There were no differences in efficacy between a single-strain (B. lupini 359a) and a two-strain (B. lupini 359a + N. galegae 0703) inoculation of plants. The tested mixed cultures of nodule bacteria did not significantly influence nodule weight, nitrogen fixation rates at the budding stage, seed number and seed weight. Conclusion. The results indicate that the binary consortia of lupine and fodder galega nodule bacteria possess the potential to affect symbiotic parameters and lupine growth at the early growth stages. Additionally, it is shown that the composition of microorganisms in mixed cultures plays an important role in determining their efficiency. The combined inoculation with B. lupini strain 359a and N. galegae strain 0702 shows the prospect for its application on lupine cultivation but additional studies of the effects of this microbial consortium involving a broad range of plant cultivars as well as different soil types are needed.