CONTAMINATION OF SEEDS AND PLANTS OF WHEAT WITH PHYTOPATOGENES OF FUSARIUM GENUS, METHODS OF RECOVERY

Abstract

Widespread production of grain crops and rejection of classical tillage technology have led to a noticeable increase of harmfulness of phytopathogens. First of all, this appertains to facultative parasites with a wide specialization - Bipolaris spp., Fusarium spp., as well as to secondary fungi from Alternaria spp., Cladosporium spp., Penicillium spp. genera and others. There is a simultaneous change of dominance in microbial community of seeds obtained in the Trans-Urals. Fungi of Fusarium spp. genus occupied the leading place among the most harmful pathogens, placing Bipolaris sorokiniana Sacc. Shoem. to the background. F. oxysporum (Schleht) Snyd, F. graminearum Schwabe, F. sporotrichoides Sherb are most spread on spring wheat, both in the tillering phase and at milk-wax stage of grain ripeness. The abundance and diversity of species was significantly higher in the tillering phase than when counted at the end of the vegetation season. To reduce the spread and development of any phytopathogen, it is necessary to apply a set of measures. One of the most effective measures is pre-sowing disinfection of seeds. However, the proposed preparations are not all equally effective in suppressing the development of the fungus of Fusarium spp. genus. During the experiment, it was found that seed treatment fungicides from the class of benzimidazoles - Zim (carbendazim), mixtures of active substances from the classes of triazoles with imidazole - HYIP (triticonazole + prochloraz), and also two triazoles - Oplot (difenoconazole + tebuconazole) were distinguished by high activity from 5.2 to 7.5 units. Application of a microbiological preparation (Bacillus subtilis), as well as its mixtures with a reduced application rate of a chemical disinfectant, showed the absence or low inhibition of fungus mycelium development.