Phytosanitary threats to oat crops on North-West of Russia

The expediency of using plant protection products in the cultivation of oat in the North-West of the Russian Federation should be based on the data of monitoring of harmful organisms in the plantings of the crop, which are not available for modern land use conditions in this region. The monitoring of spread and development of harmful organisms in oat crop was conducted in the crop rotation including cereals, grasses and row crops in Menkovo branch of Agrophysical Research Institute (Leningrad region, Gatchina district) during 2020–2023. By the results of the study composition of harmful organisms which have economic importance of the cultivation of this crop in the soil and climatic conditions of the North-West of Russia was clarified. As weed plants there were lamb’s quarters, field pansy, hempnettles, corn spurry, as pest insects were Oscinella frit and bird cherry-oat aphid (Rhopalosiphum padi), as a desease was oat leaf blotch. These species are associated with the main phytosanitary threats to oat crops, and regular monitoring and if necessary plant protection measures are required. Of secondary importance for the formation of oat yields are large cereal aphids (Sitobion avenae), leechweeds (Oulema spp.), leafminers (Agromyza spp.), leafhoppers, grain, field and grass bugs, as well as root rot, powdery mildew, crown and stem rust. Among the entomophages in oat crops, the most numerous were coccinellids and syrphids; lacewings and aphidiids were found in smaller numbers. It was revealed that the favorable phytosanitary conditions are more often observed in oat crop in the North-West of Russia that does not imply large crop losses from harmful organisms.