Fungicide protection of winter canola crops against the most common diseases

Abstract

Goal. To investigate the effect of fungicides on limiting the development of the most common diseases of winter rapeseed in the Forest Steppe of Ukraine. Methods. Field (setting up experiments, damage records, harvesting), phytopathological (identification of pathogens), information-analytical (collection and analysis of literary sources), mathematical-statistical (processing of research results). The work was carried out on the experimental fields of the Oleksandriya SE EB of the Belotserkiv district of the Kyiv region. Fungicides with different active substances were studied: azoxystrobin + cyproconazole, flutriafol + tebuconazole, boscalid + dimoxystrobin, metalaxyl-M + mancozeb, prothioconazole + tebuconazole, tebuconazole. Results. The weather conditions of the growing season during the research years were characterized by high average daily air temperature and insufficient rainfall and did not contribute to the widespread spread of rapeseed diseases. Alternaria caused by fungi of the Alternaria genus (A. brassicae (Berk.) Sacc., A. brassicicola Wilts. (Schw.), A. alternata (Fr.) Keissler) had the greatest spread and development during the years of research. In some years, downy mildew (the causative agent of the fungus Perenospora brassicae Gaeum) and fusarium wilt (Fusarium oxysporum Schlecht.) were detected on rapeseed crops with a small degree of spread and development. Treatment of crops with fungicides limited the development of rapeseed diseases during the growing season by 2.3—4.0 times. The technical efficiency of fungicides against Alternaria was on average 57.2—78.5%, against downy mildew — 69.5—73.9%. The highest effectiveness against Alternaria was provided by the Impact T fungicide, k.s. (flutriafol, 75 g/l + tebuconazole, 225 g/l), 1.0 l/ha, against downy mildew — Amistar Extra 280 SC (azoxystro­bin, 200 + cyproconazole, 80), 1.0 l/ha. Limiting the development of diseases helped to increase its yield. With the use of fungicides, the yield of rapeseed was at the level of 1.61—1.83 t/ha against 1.38 in the control, i.e. it was 16.7—32.6% higher. Conclusions. The most common diseases of winter rape during the years of research in the Right Bank Forest Steppe zone of Ukraine were Alternaria, Peronosporosis and Fusarium wilt. The dominant position in all years was occupied by Alternaria, the prevalence of which was 100%. The investigated fungicides had an effective effect on limiting the development of diseases and contributed to an increase in crop yield.