Analysis of diseases affecting winter and spring forms of Brassica napus L. and Brassica juncea L. in the central zone of the Krasnodar region

Abstract

The purpose of the research was a comparative evaluation of the disease affection of spring and winter forms of Brassica napus and Brassica juncea on the central zone of the Krasnodar region. Phytosanitary monitoring of diseases was carried out from the seedling stage. In 2011-2020, there were identified the diseases affecting winter and spring crops Brassica napus and Brassica juncea to the same extent: the occurrence frequency of downy mildew and powdery mildew was high, of Alternaria blight – from medium to high, of phytoplasma and bacterial blight – low. Differences are established for Sclerotinia disease, Phoma rot, Fusarium blight, white rust, gray rot. The occurrence frequency of Sclerotinia disease on winter form of Brassica napus and Brassica juncea varied in research years from low to medium, of Phoma rot – from medium to high; on spring forms, these diseases were noted in certain years with the low frequency. Fusarium blight affected only sowings of spring forms of Brassica napus and Brassica juncea with medium and high frequency, except for 2018-2019, when it was low. White rust affected only spring from of Brassica napus, gray rot – only winter forms of Brassica napus and Brassica juncea in certain years with the low frequency.