Uloga prostornog rasporeda kukuruza u kompeticiji s korovima

The intensity of crop competition is mostly defined by population density and spatial arrangement of plants. The effect of plant arrangement pattern of maize, in combination with the application of different herbicide rates, on weediness and maize yields were studied at the Maize Research Institute, Zemun Polje, during 2004 and 2005. Different plant arrangement patterns were designed by combining three inter-row distances (70, 50 and 35 cm) as well as by plant spacing at uniform population density. Subvariants included the application of isoxaflutole + acetochlor herbicides after sowing but prior to maize emergence at three rates: recommended, half of the recommended rate and without herbicide treatment. The number of plants per species, fresh weight of weeds, biomass and grain yield of maize were analysed. Although there were no statistical significances, the number of plants per species and fresh weight of weeds declined with the decrease in inter-row distance and, on the average, their values were the lowest in the 35-cm variant in both years 2004 and 2005 (78.52 plants m-2 and 388.65 g m-2 vs. 105.78 plants m-2 and 191.54 g m-2, respectively). The different rates of herbicide application significantly affected weediness by reducing it in both years of investigation. Maize grain yield did not vary over treatments with the recommended and half the recommended rate at the different inter-row distances and on the average.Intenzitet kompeticijskog delovanja useva na korove je uglavnom određen gustinom i prostornim rasporedom gajenih biljaka. U ogledu su ispitivani efekti prostornog rasporeda u kome se gaji kukuruz u kombinaciji sa primenom herbicida u različitim količinama, na zakorovljenost i produktivnost kukuruza tokom 2004. i 2005. godine u Institutu za kukuruz Zemun Polje. Različit prostorni raspored biljaka kukuruza je ostvaren kombinovanjem veličine međurednog razmaka (70, 50 i 35 cm) i razmaka između biljaka, u okviru iste gustine. Podvarijante su dobijene primenom herbicida isoxaflutole+acetohlor, posle setve a pre nicanja kukuruza u tri količine: preporučenoj, polovini peporučene količine i bez herbicda. Analiziran je broj jedinki i sveža masa korova, kao i biomasa i prinos zrna kukuruza. Iako nije bilo statističke značajnosti, broj jedinki i sveža masa korova su se smanjivali sa smanjenjem međurednog razmaka i u proseku imali najmanje vrednosti na varijanti 35 cm, kako u 2004. (78,52 jedinki m-2 i 388,65 g m-2), tako i u 2005. godini (105,78 jedinki m-2 i 191,54 g m-2). Primena herbicida u različitim količinama uticala je na značajno smanjenje zakorovljenosti u obe godine ispitivanja. Prinos zrna kukuruza se nije razlikovao između tretmana sa preporučenom i polovinom količine herbicida, u svim varijantama međurednog razmaka i prosečno