Reakcije populacija Xanthium strumarium L. i Helianthus annuus L. na nikosulfuron

Responses of two populations of Xanthium strumarium L. (XS1 i XS2) and three populations of Helianthus annuus L. (HA1, HA2, HA3) to nicosulfuron were studied in controlled environment. Nicosulfuron applied at five different rates (0, 40, 60, 80 and 120 g ha-1) when plants developed two pairs of leaves and control plants were not treated. Plant responses to growing rates of nicosulfuron were determined based on the next parameters: leaf area, fresh and dry weight, 7 days after herbicide application. Responses of populations of X. strumarium and H. annuus to nicosulfuron were different depend on population, herbicide rate and studied parameters. Resistance was not confirmed for any population. Namely, only reduced susceptibility of populations XS2 i HA2 to this herbicide were determined in comparison with referent susceptible populations.Reakcije 2 populacije Xanthium strumarium L. (XS1 i XS2) i 3 populacije Helianthus annuus L. (HA1, HA2, HA3) na nikosulfuron su ispitivane u kontrolisanim uslovima. Nikosulfuron je primenjen u 5 različitih količina (20, 40 , 60, 80 i 120 g ha-1) kada su biljke bile u fazi dva para razvijenih listova, a kontrolne biljke nisu tretirane. Za procenu reakcije biljaka na primenu rastućih količina nikosulfurona mereni su i analizirani sledeći parametri: površina listova, sveža i suva masa biljaka sedam dana nakon primene herbicida. Reakcije populacija X. strumarium i H. annuus na nikosulfuron su bile različite u zavisnosti od populacije, količine primene herbicida i ispitivanog parametra. Ni za jednu od populacija, za koje se sumnjalo da su razvile rezistentnost na nikosulfuron, nije potvrđena rezistentnost. Naime, konstatovana je samo smanjena osetljivost populacija XS2 i HA2 na nikosulfuron u poređenju sa referentnim osetljivim populacijama