Weed activity in arable plant communities in the Central Urals (Sverdlovsk oblast).

Weed activity is an integral criterion based on the abundance and frequency of weeds occurrence in crops. Identifying the aggressive, underactive and nonactive weed species is essential for effective agriculture management. In arable plant communities of the Central Urals there are four activity groups of weeds. The group of the most active (aggressive) weeds includes 40 species or 16% of weed species present in the Central Urals. Within this group, weeds most common in crops form a group of highly active species with a high abundance (7% of the total weed species composition). The remaining 9% comprise a group of moderately active weeds which can also be considered as the most adapted to arable plant communities. Underactive and nonactive weeds make up most of the area's weed species composition (84%). Underactive weeds (82 species or 32%) were found in arable plant communities of many crops, but mainly in small numbers. The group of nonactive weeds was the most diverse and included about half of the weed species present in the Central Urals (52%). [ABSTRACT FROM AUTHOR]