According to the results of complex studies, the species composition has been determined and the morphological features of soybean fusaria pathogens have been characterized, a collection of fusarium species has been created, and the effect of agrotechnical measures and seed treatment with biopreparations on the disease development has been established. The economic advantage of pre-sowing treatment of soybean seeds with biopreparations is proved.
As a result of five-year research on the determination of the species composition of fusaria pathogens and their pathogenicity, laboratory studies have been carried out and found that in the conditions of the Eastern Forest-Steppe of Ukraine, soybean fusaria disease is caused by nine species of the Fusarium fungi. The most common, competitive, adapted to environment factors, and harmful soybean pathogens are the species F. oxysporum, F. culmorum and F. solani, which are characterized by an average pathogenicity.
Significant influence of seeds on the prevalence of infectious diseases of soybean, collected in different ecological geographical regions of Ukraine, was confirmed. Depending on the conditions of the year, the number of healthy soybean seeds was in the range of 13–72 %, not germinating — 6–47 %, in that the most prevalent pathogens were bacteria and fungi of the Fusarium genus.
The influence of agrotechnical measures (cultivar, sowing date, fertilization, tillage, previous crop) and weather conditions on the development of root rot were analyzed. As a result, it has been established that the development of root rots depends mainly on the phase of plant development (61,6 %) and weather conditions (28,3 %) during the growing season of culture. To a lesser extent, the cultivar (16,1 %) and sowing time (19,4 %) were affected; the effect of fertilization background on the disease development was insignificant (5,6%).
Dependence of variation of soybean rots development over the years from weather conditions in vegetative periods of culture was observed, that was due to fluctuations of temperature and excessive amount or absence of precipitation during the growing period, mainly in critical phases of plants development (sprouts, flowering).
The research was conducted to determine the effect of biopreparations on the growth of Fusarium fungi mycelium in vitro. Established in laboratory conditions, the high efficiency of individual drugs in limiting the development of Fusarium pathogens on the nutrient medium (PGA). Thus, Vitawax 200 FF and Hetomik restricted the growth of mycelial fungus by 93,3–100 %.
The use of drugs for seed treatment before sowing contributed to an increase in the oil content by 0,4–0,9 % in all experimental variants compared to control. Seed treatment with Rizobofit and Biopolycid increased the protein content by 1,9–3,0 %.
Investigated preparations Biopolycid, Hetomik, Risoplan and Vitawax 200 FF had a high technical efficiency in protection against root rot, which was in the phase of sprouts 49,2–76,9 %, in the flowering phase — 28,0–63,6 %, and in the ripening phase 18,9–25,6 %. The economic efficiency of the implemented protection measures was calculated. The cost-effectiveness of biopreparations was within the range of 91,2–99,9 %. The most cost-effective was Biopolycid, the profit counted 3000,0 UAH/ha.
