Improvement of an ecologically safe system of control of fungal diseases for growing on the basis of organic farming

Goal. To assess the level of effectiveness of the elements of control of fungal diseases in potato agrocenoses for various combinations of biofungicides with biologically active substances and fertilizers, methods of application and the reaction of potatoes of the Myroslav variety to them, for growing on the basis of organic farming. Methods. The following methods were used during the research: field — monitoring of the main diseases of potatoes in field experiments, crop accounting, determination of the effectiveness of combinations of biofungicides with plant growth regulators, organic and organo-mineral fertilizers; laboratory — accounting for damage to tubers by diseases, according to generally accepted methods. Results. In 2021—2022, the Laboratory of Immunity and Plant Protection of the Institute of Potato Breeding of the National Academy of Sciences conducted research on improving the elements of an environmentally safe system of controlling fungal diseases for cultivation based on organic farming. The research used the Myroslav variety of the institute’s selection, biopreparations with insecticidal, fungicidal and growth-regulating action, and organic and organo-mineral fertilizers. The lowest level of Alternaria development was noted in option 9 (treatment of tubers — organic fertilizer + PPR + plant treatment Bactophyt + PPR + organic and organo-mineral fertilizer), the development of the disease was 25.0%, the spread was 35.0 %, and the technical efficiency of the elements protection was 56.7%. It was established that for effective control of the development of common scab, rhizoctoniosis and fusarium dry rot, it is advisable to use a mixture of substances (PPR + organic fertilizer — treatment of tubers + biofungicide + organic and organo-mineral fertilizer + PPR — plant treatment), which significantly reduced the level of disease development tubers and limited their spread, compared to control and standards. The yield of potatoes in the variants was higher than in the control (22.5 t/ha) and was in the range of 31.1—42.0 t/ha. The level of the preserved harvest, relative to the control, was in the range of 8.6—19.5 t/ ha. The highest level of yield is 42.0 t/ha, noted in option 9 (organic fertilizer + PPR treatment of tubers + three Bactophyt plant treatments + organic and organo-mineral fertilizer + PPR) which, respectively, is 19.5 t/ha higher than the control and by 3.1 t/ha — standard. Conclusions. The use of tank mixtures of biofungicides with growth regulators and fertilizers significantly reduces the level of potato disease development and helps to increase the level of its yield. It has been established that the mixture of drugs (PPR + organic fertilizer — treatment of tubers + biofungicide + organic and organo-mineral fertilizer + PPR — plant treatment) is advisable to use to control the development of alternariosis, common scab, rhizoctoniosis and fusarium dry rot, since such a combination is ecologically safe for the environment, at the same time significantly reduces the level of development of fungal diseases and limits their spread, in comparison with control and standards, for growing on the basis of organic farming.