Root rot of winter wheat and its harmfulness

Among the diseases of cereal crops root rots occupy a special place, because they can harm plants in all phases of development, infectious beginning is stored on seeds in soil, plant residues. They are widely spread everywhere crops are cultivated, having a diversity of species and strains. The harmfulness of root rots manifests itself in relation to sowing material, reducing germination, vigor, amaze shoots, hurt during the growing season, causing skinny grains, reducing the quality and yield of crops. The aim of the research was to analyze the species composition of root rots and its harmfulness in Central Russia. The literature data and own research results were analyzed. It has been established that Helminthosporium (ordinary) rot (causative agent is an imperfect fungus Bipolaris sorokiniana Shoem. ( Drechslera sorokiniana = Subram., Helminthosporium sativum p., k. et.). The disease causes a violation of the physiological and biochemical functions of plants, decreasing the amount of chlorophyll in the leaves, the change in the composition of amino acids, long-term containment of the growth of plants. Fusarium rot is caused by mushrooms of the genus Fusarium, mostly, F. culmorum Sacc, F. avenaceum, F. oxysporum lesion Sacc Schlecht. It strikes parenchyma and lub, which leads to еmpty ear of wheat. Harvest shortfall may reach 20% or more. Pythium rot ( Pythium Pringsh. ( P. irregulare Buis, P. Sideris' s polymorphon, etc.) causes a delay in plant development. Rizoktonia rot ( Cercosporella herpotrichoides Fron. Exciter) most often affects the sprouts, and can affect the roots, which darken and crumble. Cercosporella radical decay can lead to the death of individual stems or entire plants. Reduced mass of 1000 seeds reaches 16.5%, while the number of beans-to 26.5%. Ophiobolus rot ( Gaeumannomyces graminis van Ark et Oliver (= Ophiobolus graminis Sacc.) infects the root system of the plant causing poor tillering, withering leaves and dying off productive stalks, skinny grain, "white ear". Snow mold Microdochium nivale activator is called ( Fusarium nivale Ces), but often F. avenaceum, F. culmorum Sacc Sacc., etc. and leads to death of leaf sheaths and even site tillering, rare crops.