Fungicidal and growth-stimulating effect of Rheum rhaponticum L. roots and leaves plant extracts in the soybean seeds presowing treatment

The aim of our research was the determination of the fungicidal and growth-stimulating effect of Rheum rhaponticum roots and leaves extracts in the soybean seeds presowing treatment. The methods of cultivation and research of R. rhaponticum plant materials presented in this work was carried out at the Institute of Genetics, Physiology and Plant Protection (2019). The subject of our study the bioactive substances of R. raponticum L. roots and leaves of manual collection were used. As an object of research were used phytopathogens of cereals, the genus Neocosmospora micromycetes, which are capable to cause damage to all vegetative organs and contaminating the grain with mycotoxins during the growing season and storage. It was found that the number of seedlings root nodules in the standard is 3,5 times less than in the control, while in variant V3 (0,5 % L + 1,5 % R) is 36,4 % more than in control. R. raponticum L. roots extract in natural background stimulated the germination of soybean seeds by 59,5 % in comparison with the control. It was determined that the biological effectiveness of composition V3 in the control of Neocosmospora solani (Mart.) L. Lombard & Crous phytopathogens of soybean seeds was 85,4 %, which exceeds the effectiveness of its constituent extracts individually and the standard in conditions of infected background. It was proved that the combination of root extracts and rhubarb leaves combines stimulating and fungicidal (biological effectiveness 85,4 %) properties for soybean seeds.