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The demand for ecologically cultivated fruits is growing each year, but the yields in organic farming are still lower than the yields in conventional farming. Moreover plant pathogens are a serious threat in organic fruit production and the assortment of conventional pesticides is limited in organic farming. The European Commission has established regulations that state which types of bioproducts can be used in organic farming. Appropriately chosen biopreparations might be a solution to this problem. Biopreparations are products used to inhibit the growth of pathogenic fungi or bacteria, stimulate plants growth and enhance plant nutrient uptake. They can be composed of plant growth promoting bacteria and fungi, plant extracts or animals-derived compounds. The second category of bioproducts useful for enhancing yield and nutrient uptake are biostimulants. They can be composed of microorganisms, protein hydrolysates, seaweed extracts and other substances. Bacteria, fungi and yeasts are used in biocontrol of plant pathogens and in enhancing plants growth by producing hormone-like substances and reducing symptoms of environmental stress caused by weather or soil factors such as drought or low nutrient availability. [ABSTRACT FROM AUTHOR]

Biopreparations based on an inoculum of beneficial bacteria may become an essential tool in the prevention of fungal and fungal-like phytopathogens with cause a decrease in the yield of raspberries, especially in organic farming, in which the use of conventional plant protection products is prohibited. The research is based on a pot experiment which includes 4 different naturalization strategies and 5 different pathosystems. The application of environmental isolates of plant beneficial bacteria belonging to genera Arthrobacter , Pseudomonas , and Rhodococcus to the raspberry plant was performed in order to characterize their effect on the microbial communities surrounding the raspberry plant. The application of pathosystems consisting of fungal and fungal-like pathogens belonging to the Botrytis , Colletotrichum , Phytophthora , and Verticillium genera allowed for an analysis to be conducted with regard to the effect of naturalization treatments on microbial communities of raspberry plants infected with phytopathogens. Rhizosphere and shoots samples were subjected to a functional profiling analysis of their microbial communities with the use of Biolog® EcoPlates. Furthermore the DNA was isolated from the rhizosphere and shoots of raspberries and sequenced using the Illumina MiSeq platform. The application of a bacterial inoculum resulted in a decrease in the substrate stress index of raspberry shoots microbiota. Over 95 % of the fungal phyla found in the rhizosphere consisted of 3 phyla: Ascomycota , Mortierellomycota , and Basidiomycota. The results obtained indicated, that the application of plant beneficial bacteria to raspberry plants roots during planting, and afterwards during the watering, may be an important way of inhibiting the negative effect of plant pathogens and enhancing the functional abilities of microbial communities. [Display omitted] [ABSTRACT FROM AUTHOR]

The current study focuses on the optimization of bacterial growing medium composition, including the carbon and nitrogen source in different concentrations, the pH value of the medium and the temperature. Optimization was performed for four environmental bacterial isolates belonging to the genera Arthrobacter, Pseudomonas and Rhodococcus, which were previously obtained from wild raspberries. These bacteria proved to be potent antagonists against certain fungal and fungal-like plant pathogens. Furthermore, three preservation methods and three sample preparation techniques were evaluated. In addition, a prebiotic supplementary blend based on previous research was tested. The research included a pot experiment to estimate the influence of bacterial cultures on the growth of plant shoots and roots, on the soil enzymatic activity and the content of macronutrients, minerals and nitrogen in the soil depending on the naturalization strategy. The best carbon and nitrogen source were chosen. The addition of a supplementary blend resulted in the increased growth of two bacterial isolates. Bacterial inoculum applied to the roots and watering resulted in increased shoot mass in objects infected with plant pathogens, although in plants without the pathogen infection, bacterial inoculum resulted in the decreased mass of plants. Naturalization strategy should be matched to the pathogens present at plantations. [ABSTRACT FROM AUTHOR]

The threat caused by plants fungal and fungal-like pathogens is a serious problem in the organic farming of soft fruits. The European Commission regulations prohibit some commercially available chemical plant protection products, and instead recommend the use of natural methods for improving the microbial soil status and thus increasing resistance to biotic stresses caused by phytopathogens. The solution to this problem may be biopreparations based on, e.g., bacteria, especially those isolated from native local environments. To select proper bacterial candidates for biopreparation, research was provided to preliminarily ensure that those isolates are able not only to inhibit the growth of pathogens, but also to be metabolically effective. In the presented research sixty-five isolates were acquired and identified. Potentially pathogenic isolates were excluded from further research, and beneficial bacterial isolates were tested against the following plant pathogens: Botrytis spp., Colletotrichum spp., Phytophthora spp., and Verticillium spp. The eight most effective antagonists belonging to Arthrobacter, Bacillus, Pseudomonas, and Rhodococcus genera were subjected to metabolic and enzymatic analyses and a resistance to chemical stress survey, indicating to their potential as components of biopreparations for agroecology. [ABSTRACT FROM AUTHOR]