Frequency of diseases on black mustard (Brassica nigra (L.) W.D.J. Koch) in the Central zone of the Krasnodar region depending on the weather conditions

The purpose of the research was to determine frequency of diseases occurrence on black mustard in environments of the central zone of the Krasnodar region depending on the weather conditions. We conducted our researches in 2011-2019 in the V.S. Pustovoit All-Russian Research Institute of Oil Crops (VNIIMK) on fields of black mustard variety Niagara bred in VNIIMK. Annually we observed high frequency of false and downy mildews, high and middle - of Alternaria blight. Weather conditions influnces a frequency of fusariose plant wilt: in conditions of insufficient moistening it was high and average, in conditions of abundant moistening diseases frequency decreased till low level. Mustard plant infection with Sclerotinia with low frequency we stated in 2015-2017, when combining high indicators of hydrothermal coefficient (1.4-1.6) and relative air moisture of 59-66%. Phoma infection symptoms on individual mustard plants we revealed in 2012 when combining relative air moisture of 59% and hydrothermal coefficient equal 0.8. The highest seed yield and oil content in seeds of black mustard we noted in years with low Fusariose frequency (2015-2017), they were: 1.69-2.48 t per ha and 35.3-36.0%, respectively. Essential oil content did not depend on the diseases frequency on the mustard (0.80-1.09%).