Frequency of occurrence of heterodera schachtii on oil crops from Brassicaceae family in the Krasnodar region

A beet cyst nematode Heterodera schachtii Schmidt is an obligate parasite, which infected many kinds of agricultural crops in different countries. It penetrates into internal tissues of plant root and causes mechanical destructions of cells. The disease manifests itself in a form of plant wilting. Yield decrease can reaches up to 50%. The purpose of the research was to determine frequency of occurrence of the beet cyst nematode Heterodera schachtii Schmidt in sowings of winter and spring oil crops from a Brassicaceae family in the Krasnodar region. The observations of sowings of the studied crops were conducted in phases of a vegetative period 2-4 true leaves and green pod on fields of the V.S. Pustovoit All-Russian Research Institute of Oil Crops in 2010-2023. In these phases, 20 plants were selected on ten equidistant plots diagonally across the sowings of each crop. The frequency of occurrence of Heterodera schachtii was calculated as a ratio between numbers of sick and healthy plants expressed as a percentage, and then divided into groups: infected plants are absent; low (to 10% of infected plants); average (from 11 to 50% of infected plants); high (51% and more of infected plants). The beet cyst nematode was allocated in plants of all studied crops, besides winter and spring false flax. In years, when the disease was stated in sowings of oil crops from the Brassicaceae family, the frequency of the diseases occurrence was low (up to 10%) in both phases of plant development 2021. And in 2021, it increased to average level (11-18%) on winter and spring rapeseed and brown mustard. An infection degree of plants of all studied groups was equal 1-3 points with a predominance of 1 point.