Possibilities of weed control in oilseed rape (Brassica napus L.) with herbicides available on the Slovenian market

V enoletnem poskusu, izvedenem v letu 2009, smo proučevali možnosti kemičnega zatiranja plevelov v ozimni oljni ogrščici (sorta PRD 03). Uporabili smo 10 različnih kombinacij herbicidov na podlagi metazaklora, klomazona, klopiralida, dimetaklora in piklorama. Analizirali smo stopnjo učinkovitosti herbicidov, fitotoksičnost herbicidov ter pokrovnost parcelic z pleveli, v času dveh ocenjevanj. Prvo ocenjevanje je bilo izvedeno septembra, drugo pa spomladi, meseca aprila. Pri analizi skupne povprečne učinkovitosti herbicidov, smo ugotovili značilno manjšo učinkovitost dveh herbicidnih kombinacij, na podlagi klomazona ter klopiralida s pikloramom. Vseh ostalih 8 herbicidnih kombinacij je bilo visoko učinkovitih in se po stopnji učinkovitosti niso razlikovale med seboj. Nobena od preučevanih herbicidnih kombinacij ni povzročila pojavov kakršnih koli vizualno prepoznavnih znakov fitotoksičnosti na posevku ogrščice. Preučevani herbicidi, ki so dostopni na Slovenskem trgu nudijo zadovoljiv nivo možnosti za zatiranje plevelov v oljni ogrščici.In a field experiment conducted in 2009 we evaluated possibilities of chemical weed control in winter oilseed rape (cultivar PRD 03). Ten herbicide combinations based on metazachlor, chlomazone, clopyralid, dimethachlor and picloram, were tested in terms of efficacy to control weeds and in terms of their phytotoxicity to oilseed rape during two periods of the growth season (September, April). As a result of the trial it was demonstrated that two herbicide combinations, based on chlomazone and clopyralid mixed with picloram provided a lower average efficiency of weed control than the rest of the tested substances in our trial. Other eight herbicide combinations showed very high level of weed control. Their level of efficacy did not differ significantly among each other. None of the tested herbicide combinations caused any clearly visible symptoms of phytotoxicity to the rape plants. The studied herbicides which are also available on the Slovenian market, offer a sufficiently high level of weed control for oilseed rape crop