EFFECTS OF TILLAGE SYSTEMS AND FERTILIZATION LEVEL ON THE WEEDINESS OF WINTER WHEAT

This paper deals with results of the effects of three tillage systems and differentnitrogen fertilizer level on floristic composition of weed community in winterwheat in investigated period on the chernozem-luvic soil type. The trial was carriedout on the estate experimental field of the Faculty of Agriculture - Zemun"Radmilovac" near Belgrade in Serbia. Tillage systems and fertilization withnitrogen fertilizers have a big influence on weed control and floristic composition,number of species and individuals and biomass of weeds in winter wheat. Theweed community in winter wheat crops was composed of 14 weed species in bothyear of investigation, respectively, with dominancy of terophytes. The obtainedresults showed that the dominant weed species were Avena fatua L., Papaverrhoeas L., Sinapis arvensis L. and Stellaria media (L.) Vill. from annuels and.Convolvulus arvensis L. from perennials prevailed in the weed community inwinter wheat crops.Conventional tillage system with nitrogen level in top dressing120 kg ha-1 had better effect in weed control than both of both investigatedconservation tillage systems (MTS and NTS) had. However, mulch tillage has notlagged behind the conventional tillage increased total weed number of individualsannual and perennial species especially fresh biomass. No-tillage system makesweed control difficult