INFLUENCE OF FUNGICIDAL DISINFECTANTS ON PATHOGENIC COMPLEX AND LABORATORY GERMINATION OF SOYBEAN SEEDS

Abstract

The article presents data on the phyto-sanitary condition of soybean seeds of Vilshanka, Elena and Vorskla varieties, the level of contamination with pathogenic microorganisms. The aim of the research was to evaluate the effectiveness of fungicidal disinfectants against fungal and bacterial infections of soybean and their impact on seed quality. The variants of the experiment included: 1. Control. 2. Fundazole, 500 g/kg of wetted powder (w.p.). (St) 3 kg/t. 3. Vitavax 200 FF, 400 g/l water suspension concentration (w.s.c.). 4. TMTD 400 g/l s.c. 6 l/t. 5. Vial Trust, 140 g/l: s.c. 2.5 l/t. To establish the effect of disinfectants on the condition and development of soybean plants, they were grown to the phase of two true leaves in containers. It was found that the total infection rate of soybean seeds with phyto-pathogenic microorganisms was 27.3–37.0 %, while the infection rate with fungal infection was 68.3–83.9 % of the total and mixed infection made 6.4–17.3 %. The incidence of bacterial infection was within normal limits (up to 5 %) in Elena (3.5 %) and Vilshanka (2.3 %) varieties. In Vorskla variety, this indicator was 6.4%. Fungi of Alternaria genus were de-tected most often – 5.3–11.3 %, depending on the variety. Fungi of Fusarium genus were less spread: 3.9–6.5 % of the total number of seeds affected by pathogens of fungal etiology. Fungi of Botrytis genus were characterized by insignificant manifestation – in the range of 2.5–3.5 %, depending on the variety. Spores of these pathogens were found on the seeds of Elena and Vorskla simultaneously. Representatives of secondary infections (Aspergillus, Mucor and Penicillium), the prevalence of which was 4.4–10.1 %, were widely rep-resented on soybean seeds. The share of each of these pathogens, with the exception of Mucor, was insignifi-cant – from 0.5 % to 2.5 %. The share of detected fungi of Mucor genus was slightly higher; the maximum was in Elena variety – 5.5 % and the minimum – in Vilshanka variety – 3.3 %. For seed disinfection from pathogenic flora of fungal and bacterial origin, it is expedient to use a two-component fungicidal pesticide Vitavax 200 FF, 400 g/l w.s.c. with application rate of 2.5 l/t of seeds, which also has the best stimulating effect on laboratory germination of soybean seeds.