Resistance of blackgrass (Alopecurus myosuroides Huds.) to ALS inhibitors in region of south-western Poland

Abstract

The aim of the research was to identify resistant and sensitive biotypes of Alopecurus myosuroides to various substances from the ALS inhibitors group and to determine the degree of resistance to these compounds in south-western Poland. The experiments were performer by the method of biological tests. Three substances from the group of ALS inhibitors were tested. On the basis of the reduction in fresh weight of the plants, the ED50 index and the resistance index (RI) was determined. The conducted research confirmed the presence of A. myosuroides biotypes resistant to ALS inhibitors in the fields of Lower Silesia and Opole Silesia. Cross-resistance of blackbrass to sulfonylurea herbicides (i.e. sulfosulfuron, iodosulfuron-methylsodium + mesosulfuron-methyl) and to sulfonylaminocarbonyltriazolinones (sodium propoxycarbazone) was identified. Among all resistant samples, as much as 76% of A. myosuroides biotypes showed cross resistance. The highest index of resistance to propoxycarbazone and the mixture of iodosulfuron-methyl sodium with mesosulfuron-methyl was over 100 and for sulfosulfuron over 200.