Crown rust of oats: the role of variety, weather and the level of mineral nutrition in the conditions of Western Siberia

Abstract. The purpose of this study is to assess the factors influencing the incidence of crown rust in oats. Materials and methods. The work was carried out in 2020–2021 at an experimental field located in the northern forest-steppe of the Trans-Urals. The object of the study were three cultivars of Tyumen breeding: Talisman, Otrada and Foma, which were sown on different agricultural grounds, ensuring the formation of yields from 3.0 to 6.0 t/ha of grain. The length of oat vegetation was determined at different levels of mineral nutrition; the degree of disease development and its prevalence in crops. Weather conditions in the years of research differed from the average long–term data: 2020 was hot and moderately dry; 2021 was abnormally hot and arid; 2022 was moderately hot and humid. Results. It has been experimentally proved that the application of fertilizers in doses N150P60 and N200P80 increases the vegetation of oats by 18–21 days due to the prolongation of the second half of the growing season. This leads to an increase in the incidence and prevalence of crown rust. The Foma variety turned out to be the most stable, in which the considered indicators were almost two times lower relative to the Talisman and Otrada cultivars. It was found that the degree of disease development depends on the variety by 27 %; by 21 % on the dose of mineral fertilizers and by 35 % on the weather conditions of the growing season. The prevalence of crown rust in oat crops mainly depends on the variety and mineral fertilizers – the degree of influence of these factors is 43 and 35 %, respectively. Scientific novelty. For the first time, the role of each factor on the susceptibility of modern varieties of oats to crown rust was studied and determined. A correlation has been established between the level of mineral nutrition and the degree of development of the disease. Recommendations. To reduce the risk of crown rust damage to oat crops in the conditions of the Northern Urals, it is recommended to use the Foma variety with the introduction of mineral fertilizers for a planned yield of no more than 5.0 t/ha of grain (N150P60).