Abstract
L.V. Zhukova, S.V. Stankevych*, V.P. Turenko, V.V. Bezpal’ko, S.V. Bondarenko, I.V. Zabrodina, Ð. A. Poedinceva, L.V. Golovan, I.V. Klymenko and V.O. Melenti
Root rots of spring barley are considered to be outwardly barely visible diseases, but they are very harmful. With a significant degree of the disease development the growth of crops are suppressed, which affects the final result, that is the qualitative and quantitative indices of the future harvest are becoming worse. Root rots of spring barley are represented by pathogens from the genera of Fusarium spp. and Drechslera spp. The harmfulness of helminthosporiosis root rot is manifested itself in the growth retardation of the sick plants, breaking of their physiological and biochemical processes, weakening of mineral nutrition, reducing of plant productivity, and the deterioration of the grain quality. The harmfulness of fusariosis root rot is manifested itself in the slowing down of the growth and development of seedlings, leanness of crops, atrophy of productive stalks, the formation of an underdeveloped ear with the frail seeds. The favourable conditions for the pathogen development facilitate the appearance of the hollow ears on the affected plants of spring barley. The crops preceding spring barley, spatial isolation between winter and spring cereals, high quality seeds, soil cultivation, application of fertilizers and seeds treatment significantly influence the prevalence, harmfulness and economic importance of the diseases. Seeds treatment is an obligatory economically and ecologically appropriate agrarian measure, which protects the seeds, sprouts, shoots and young plants from the seed and soil pathogenic infection and provides the opportunity to protect the young plant seedlings at early stages of organogenesis.
In order to reduce the negative effects arising from the use of the pesticides in the cultivation of plants along with the chemical agents the biological preparations are used to protect the crops from the harmful organisms and the pathogens of root rots. In comparison with chemical agents the biological preparations have considerable disadvantages. These disadvantages are the low technical efficiency, strong dependence on weather conditions, and short-term protective action during the lingering development of the disease and narrow specialization.