[Erwinia amylovora--the fire blight pathogen of trees in Ukraine].

Niduses of fire blight of fruit and ornamental trees have been found in the Kyiv and Vinnitsa regions of Ukraine. Pathogen Erwinia amylovora was isolated between April and October. The pathogen was often accompanied by bacteria Pseudomonas syringae pv. syringae. Artificial infection with a mixture of bacteria E. amylovora and P. syringae pv. syringae accelerates and enhances the disease process in the laboratory.

[Curtobacterium flaccumfaciens pv. flaccumfaciens is the agent of bacterial disease of soybean].

A new phytopathogen has been identified and investigated as a result of ecosystem monitoring of bacterial soybean diseases in Ukraine which is identified as Curtobacterium flaccumfaciens pv. flaccumfaciens according to its phenotypic and genotypic characteristics. The pathogen is highly aggressive to soybean and can potentially be a threat of infection to other legumes.

[Pseudomonas syringae - the agent of bacterial diseases of weeds].

The symptoms of bacterial diseases of the associated weeds have been identified and described in the wheat crops grown in different farming systems. On the basis of its morphological, biochemical and serological properties the agent isolated from frost-blite, barnyard grass, wild radish, couch grass, bottle-brush, bindweed and sow thistle has been identified as Pseudomonas syringae. Serological affinity between the weed bacteria and the agent of bacterial diseases of cereals has been established.

[Basal bacteriosis of wheat and influence of agrotechnical methods on its spread].

Monitoring of bacterial diseases of wheat was conducted allowing for different doses of mineral fertilizers and crops predecessors. It is shown that symptoms of development of the basic disease of wheat, which is caused by Pseudomonas syringae pv. atrofaciens, varied depending on agrotechnical methods, stages of plant growth and environmental factors. Introduction of different doses of nitrogen, phosphate and potassium fertilizers, especially high ones, increases the damage of wheat by the agent of basal bacteriosis P. syringae pv. atrofaciens. Strains of this pathogen, isolated from the infected wheat plants, affect in the experiment such weeds as sow thistle, field horsetail, and couch grass.

[Species composition of agents of the horsetail common (Equisetum arvense L.) bacteriosises].

Bacterial diseases of weeds horsetail common (Equisetum arvense L.) were revealed in the crops of wheat and soya in the fields of Kyiv and Vinnitsia Regions of Ukraine. The distinctive symptoms of bacterial affections on the root neck, on stalks of vegetative and spore shoots, on twigs were brown, dark brown or almost black necrotic spots of oblong form. The necroses increased in size, embraced the stalks. The stalks broke, the plants dried up. Patterns of affected plants, isolated and identified phytopathogenic bacteria Pseudomonas syringae, Pectobacterium carotovorum subsp. carotovorum, Pantoea agglomerans and Curtobacterium sp. were analyzed These bacteria caused pathological process on the horsetail common, wheat and soy under the conditions of artificial inoculation. The composition of bacteria species was different in different years depending on temperature conditions of vegetative period.

[Role of biocompatible adhesives in the increase of rhizobia physiological activity and productivity of soybean-rhizobia symbiosis].

On the basis of natural exopolysaccharide xanthan and exopolyacrylamide the sticky-gene composition has been developed. Addition of that composition to the culture medium provided a 26.3 times higher viability of Bradyrhizobium japonicum UCM B-6035 cells during its storage. Introduction of plant growth regulators biosil or ivin into this composition increased the survival of rhizobia. Application of gel inoculant B. japonicum favored more intensive growth of rhizosphere microorganisms, nutrient's accumulation in the soil and increased productivity of soybean-Rhizobium symbiosis.

[Effect of biopreparations on dynamics of the number of bacteria and phytopathogenic fungi in potato agroecosystem].

Application of biological preparations such as Phytotsid and Planryz favoures the growth of the general number of soil's bacteria population compared with control by 13.0-36.1% in the variant of potato variety Scarbnytsya and by 4.5-24.6% of potato variety Oberig. It also decreases 1.2-1.8 times the number of soil phytopathogens--Fusarium and Alternaria. During the application of Rovral Akvaflo the Shenon's ecological index of species biodiversity was lower than during the bioprepation application. One could observe a decrease of species biodiversity and dominance of dark pigmentation in fungi--Alternaria sp., Cladosporium sp., Phoma sp., Doratomyces sp., and pigmented bacteria.

[Phytopathogenic bacteria of couch-grass in the crops of wheat].

Bacterialdiseases of weeds in the crops of wheat on the fields of Kyiv and Vinnytsya regions of Ukraine Elytrigia repens (L.) Nevski Agropyrum repens L. were revealed. The following symptoms of bacterial affections: the leaves wither, oval or hatched necrotic spots on green leaves, necroses on the stalks, empty-ears, partial blackening of the ear axes, awns, caryopsises, scales, water-soaked or dark brown with violet shade spots on the rhizomes were found. During the vegetation period bacteria were isolated from the affected plants which caused pathological process in the couch-grass and wheat. The pathogenic bacteria were identified as Pseudomonas syringae, P. viridiflava, Pseudomonas sp., Erwinia carotovora pv. carotovora, Pantoea agglomerans, the part of yellow-pigmentary isolates were not identified. Some Psyringae were isolated from the rhizomes during winterthawing. The paper is presented in Ukrainian.

[Role of Linum usitatissimum L. in formation of microbic communities of podzol soils].

Features of Linum usitatissimum L. influence on structure and biological activity of soil microorganisms have been studied at different saturation of crop rotations. It was established, that L. usitatissimum L. promotes the formation of specific microbial soil cenosis which causes intensity and orientation of separate biological processes. Essential distinctions in quantitative and qualitative structure are indicated.