ФИЛОАГРОЦЕНОГЕНЕЗ В ПОСЕВАХ САХАРНОЙ СВЕКЛЫ ПРИ РАЗНОЙ СТЕПЕНИ АНТРОПОГЕННОЙ НАГРУЗКИ В ХХВЕКЕ–НАЧАЛЕ ХХI ВЕКА

Abstract

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