Features of diseases progress on winter wheat depending on the weather conditions

Purpose. To study the influence of weather conditions on features of the main disease progress on winter wheat. Methods. The research was carried out during 2013–2017 on experimental fields of the Department of Plant Protection of the Myronivka Institute of Wheat. Experiments using artificial inoculation of plants with pathogens were laid down according to the method of the State strain testing of crops. Plant resistance to causal agents of disease (brown rust, powdery mildew, Septoria leaf blotch, eyespot, common bunt, Fusarium head blight) was evaluated according to the conventional techniques. Statistical processing was carried out with algorithms of Main effects ANOVA, regression and correlation analysis in the programme Statistica 10.0. Results. It was revealed that in the years of the research plant damage caused by diseases was different depending on meteorological conditions. After thoroughly analyzing the weather conditions of each growing season, it was found that 2013, 2014 and 2016 were the most favorable year for the disease progress (Hydro-thermal Coefficient of Selyaninov (HTC) was 1.3, 1.6 and 1.5, respectively). A smaller degree of winter wheat plants damage by pathogens of major diseases was noted in 2017 (HTC = 0.8, insufficient moisture). Then brown rust and Septoria leaf blotch on winter wheat plants were not detected, and the damage by powdery mildew on the susceptible variety did not exceed 15 %. Eyespot progress was also not high. Weather conditions caused the least influence on the common bunt progress, so the disease was manifested annually with constant high damage level. The influence of year conditions (57.7–80.1 %) was significant (p < 0.05) and for the most diseases exceeded the influence of variety (11.3–30.2 %), excepting powdery mildew (47.1 %) and common bunt (62.9 %). Conclusions. The results of the studies confirm that winter wheat disease progress are significant under increased rainfall in May–June (if the HTC exceeds 1.5), as well as in increased temperature conditions. Both positive and negative correlations of disease progress with total temperature and total precipitation were determined. Thus, conditions of cropping season essentially influenced on winter wheat disease affection.