Effects of crop density and herbicide treatment on the floristic composition and structure of weed community in maize

Abstract

Effects of crop density and herbicide treatment on the distribution of weed species in a weed community in maize at the location of Zemun Polje were investigated. During the maize growing seasons in 1996 and 1997, floristic composition and structure of weed community were surveyed. Furthermore, the number of species, number of plants per species and fresh weight of all weeds per area unit over all densities in both treated and untreated variants were also determined. Changes, occurring under effects of higher maize crop densities and herbicide application, were analysed on the basis of distributed weed species and their plants per species. Moreover, relative distribution of certain weed groups was determined. Significant effects of crop density x herbicide application interaction were observed in reducing the relative distribution of certain broad-leaved and perennial weeds in the total maize weediness at Zemun Polje.

Proučavan je uticaj gustine gajenja useva i primene herbicida na zastupljenost vrsta korova u korovskoj zajednici kukuruza, na lokalitetu Zemun Polja. Tokom vegetacionog perioda kukuruza u 1996. i 1997. godini, sniman je floristički sastav i građa korovske zajednice i utvrđen broj vrsta, broj njihovih jedinki i sveza masa svih korova po jedinici površine, u svakoj gustini. Na varijanti sa i bez primene herbicida. Na osnovu zastupljenosti vrsta korova i njihovih jedinki analizirane su promene nastale pod uticajem povećanja gustine kukuruza i usled primene herbicida i izračunata relativna zastupljenost pojedinih grupa korova. U obe godine ispitivanja došlo je do redukcije korovske zajednice sa povećanjem gustine useva u uslovima bez, a naročito u uslovima sa primenom herbicida. Značajan uticaj interakcije gustine i primene herbicida je ostvaren kod smanjenja relativnog učešća grupe uskolisnih i višegodišnjih korova u ukupnoj zakorovljenosti kukuruza Zemun Polja.