Structure of micromycete complex of feed crops in the forest steppe of Western Siberia

Abstract

The article highlights the experimental results on the structure of micromycete complex of feed crops seeds in the forest-steppe of Western Siberia. The researchers investigated more than 50 sets of seeds of different soya varieties (Glycine hispida), chick-pea (Cicer arietinum), spring rape (Brassica napus), red clover (Trifolium pratense) and lupine (Lupínus polyphyllus). The authors observed that micromycete complex contains a lot of seed infections in the mafic hyphomycetes of the genus Alternaria (average of 15.8–52.3 %) and Cladosporium (5,7–38,0 %), less common were Fusarium fungi and fungi. The distinguished fungi contained smaller number of Pythium, Botrytis, Verticillium, Rhizoctonia, Curvularia, Peronospora, Stemphylium, Ascochyta, Trichotecium and Corynespora. The article reveals the features of the structure of micromycetes complex on the lupine seeds. The seed material was strongly infected by Colletotrichum lupini (Bondar) Nirenberg, Feiler & Hagedorn (from 37.5 to 62.5%, depends on the variety), which strongly damaged the crops during the growing season (the disease development index varied from 30 to 100 %). The concentration of Fusarium fungi on the seeds of all crops varied from 2.6 to 15.4%; the authors observed the dominating species as F. oxysporum, F. oxysporum var. orthoceras, F. solani, F. solani var. argillaceum, F. sambucinum, F. sambucinum. var. minus, F. gibbosum, F. avenaceum, F. sporotrichiella var. poae. The authors found out that fungi (species of Penicillium, Aspergillus, etc.) is more extracted from the seeds in humid years like 2015, compared with more droughty years like 2016 and 2017. They were mostly observed in the rape seeds (20,2%) and chick-pea (15.8 %). The results of the phytoexpertise show that the problem of contamination of fodder crops by pathogens and the saprophytic mycoflora leads to bed quality of forage crops and seed germination. This problem is very urgent and relevant in, the conditions of forest-steppe of Western Siberia. The high level of seed infection indicates the necessity to strong following the procedure of storage and pre-treatment of seeds with chemical or biological agents.