Study of the effect of the combined fungicide Abacus Ultra on the population structure of the wheat leaf rust pathogen

Aim. To study the variability of intrapopulation structure causative agent wheat leaf rust ( Puccinia triticina Erikss.) on basis pathogenicity under influence combined fungicide Abacus Ultra, SE. Material and Methods. The studies were carried out in greenhouse complex Federal Research Center Biological Plant Protection winter variety Krasnodarskaya 99 which is susceptible to rust. material studied was SE with application rates 0.75; 1.0; 1.25; 1.5; 1.75 l/ha. work according generally accepted methods. Results. impact different average virulence P. population established, this indicator varying from 40.0% (control [without treatment]) 19.5% (fungicide rate l/ha). As a result analysis phenotypic composition population, 5 phenotypes identified. A decrease viability spores fungus an increase 69.1% (0.75 l/ha) 29.2% (1.75 aggressiveness drug established. biological effectiveness against pathogen 95.3–97.8% at recommended 1.0–1.5 Conclusion. showed that treated chemical characterised by change terms virulence, while sensitivity remains high due combination active substances pyraclostrobin epoxiconazole mechanism action preparation.