Effectiveness of fungicides in reducing harmfulness biotrophic pathogens on spring rape

Abstract

The results of studies assessing the biological and economic effectiveness of fungicides from various chemical groups on spring rapeseed crops in the south of the Non-Chernozem Zone are presented. It has been established that the biotrophic pathogens Peronospora Brassicae Gaeum and Erysiphe communis Grev reduce damage to spring rape throughout most of the growing season. The estimated biological effectiveness established that the economic effect in relation to downy mildew and powdery mildew was after propiconazole (300 g/l) + theonazole (200 g/l) at a dose of 0,5 l/ha and azoxystrobin (240 g/l)  + epoxiconazole (160 g/l) at a dose of 0,7 l/ha when applied in the phase of formation of rosette leaves - transition to stemming and in the flowering phase of rapeseed. The prevalence of downy mildew reduced mainly from 32 to 37%, of  powdery mildew from 54 to 59%. The development of diseases decreased by 44–78% and 74%. The use of fungicides containing these active substances contributed to the production of economic yields of spring rapeseed of 2.83 and 2.70 t/ha, which was higher compared to the control by 0.90 and 0.77 t/ha, respectively.