EN
The intensive use of acetolactate synthase (ALS) inhibitors for crop protection in many cases caused arising of weed resistant biotypes to these herbicides from this groups. In 2004–2010 seed material of wind grass (Apera spica-venti) were collected from 151 field were a very poor control of this weed was recorded after using ALS inhibitors. The collected seeds were tested in the greenhouse experiments. The results of greenhouse test revealed that on 48% of assessed fields showed the presence of A. spica-venti biotypes resistant to sulfonylurea herbicides, and the resistance problem become of a regional importance. Some resistant biotypes of Chenopodium album and Amaranthus retroflexus to metamitron were also found. And also some biotypes of Alopecurus myosuroides target site resistant to iodosulfuron + mesosulfuron were found. It should be emphasized that herbicide resistance phenomenon may increase in the nearest future, and every year some new resistant biotypes of different weed species are detected.