EVOLUTION OF WEED FLORA IN SUGAR BEET CROPS UNDER DIFFERENT DEGREESOF ANTHROPOGENIC LOAD IN THE 20TH CENTURY AND EARLY 21STCENTURY

The south of the Non-Chernozem Region is north-ern boundary sugar beet production in Russian Fed-eration. An important factor restraining growth crop productivity high weed infestation crops. To devel-op an effective system protection against weeds, it necessary to study their species composition order determine most occurring and noxious species. available data geobotanical surveys since 1930s showed that at different levels anthropogenic impact core was formed. Under extensive agriculture conditions, following were widespread ones: Elytrigia repens(L.) Nevski, Equiseeum arvenseL., Sonchus arvensis L., Convolvulus arvensisL., Cirsium setosum(Willd.) Besser., Artemisia absinthiumL., Chenopodium albumL., Polygonum avicula-reL., Apera spica-ventiL., etc. introduction mechan-ical plowing decreased population density A. Dracocephalum thymiflorumL., P. aviculareL. Further intensification contributed narrowing composition. Avena fatuaL., not previously found, appeared abundance crops surpassed all other terms number frequency occurrence, as well resistant herbicides from 2.4-D dimethylamine group -Poaceae, Galium aparineL., Tripleurospermum inodorum(L.) Sch. Bip. Couch grass(Elytrigia Nevski) com-pletely substituted. Currently, agrophytocenoses con-tain harmful rhizome root-sucker weeds spring Thefollowing early are par-ticularly highly spread crops: common wild oat (Avena fatuaL.), hemp-nettle (Galeopsis), albumL.; overwintering which seeds accumulate soil during cultivation rotations where control so intense.