The effect of fungicides on reducing the harmfulness of Alternaria blight of brown mustard

Abstract

Abstract Alternaria blight (pathogens are fungi Alternaria spp.) is one of the most harmful diseases for brown mustard. We carried out the research at V.S. Pustovoit All-Russian Research Institute of Oil Crops in 2017-2019 on the brown mustard variety Nika. In all variants we counted the mustard plants affected by Alternaria blight at the yellow pod stage, during the most intensive development of disease on plants. The aim of the research is to study the effect of modern fungicides on reducing the harmfulness of brown mustard Alternaria blight in the central zone of the Krasnodar region. We established that the treatment of brown mustard plants with fungicides at the green pod stage reduced the prevalence and development of Alternaria blight by 50.0-64.0 and 27.0-36.5 %, respectively, in comparison to the control (92.0 and 44.0 %, respectively). The preparations containing tebuconazole 250 g/l, EC and boscalid 200 g/l, SC showed the best biological effectiveness – 80.0-83.0 %. The yield of brown mustard seeds in variants with these preparations significantly exceeded the control (by 0.40-0.48 t/ha). The oil content of seeds was significantly higher than the control (by 3.8-6.5 %) in variants with tebuconazole 250 g/l, EC, boscalid 200 g/l + dimoxystrobin 200 g/l, SC and azoxystrobin 200 g/l + cyproconazole 80 g/l, SC.