The action, efficiency and selectivity of the herbicides acetochlor, isoxafluthol, oxadiargyl, thifensulphuron-methyl, atrazine, dicamba, nicosulphuron, rimsulphuron, and their combinations in maize were investigated In experiments conducted in Pancevo and Zemun in 1997-1999. After several consecutive years of herbicide application, changes in the floristic composition and structure of the weed community, and an Increase In the resistant weed species were observed. The dominant weed species In maize were: Polygonum persicaria, Datura stramonium, Xantium strumarium, Abutilon theophasti, Ambrosia artemisifolia, Stachys annua, Chenopodium album, Solanum nigrum, Setaria spp., Sorghum halepense and Echinochloa crus-galli. After several consecutive years of acetochlor application an over multiplication of Polygonum persicaria, and Xanthium strumarium was observed, while the application of isoxafluthol led to an Increase of Datura stramonium in maize fields.
