Contrasts among origins of corn hybrids in relation to their susceptibility to nicosulfuron and isoxaflutole herbicides

Abstract

Herbicide selectivity is the basis for successfull weed chemical control in agricultural production, as it is considered as a measurement of the difeerential response of different plant species to a certain herbicide. The objective of this work was to evaluate the effect of the origin of corn hybrid in relation to its susceptibility to the herbicides nicosulfuron and isoxaflutole. The research was conducted in greenhouse conditions and comprised two experiments, being the first one with nicosulfuron (09/09/2005 to 10/24/2005) and another one with isoxaflutole (10/09/04 to 11/10/04). Both experiments were run in a randomized blocks design, in a factorial scheme 33x3 for nicosulfuron and 23x3 for isoxaflutole, with four replicates. The first factor was constituted by corn hybrids and the second one by herbicide rates. After herbicide spraying, shoot dry biomass was evaluated. It was concluded that origins of corn hybrids affects the susceptibility to the herbicides nicosulfuron and isoxaflutole. In average, Balu and Codetec hybrids were the most sensitive to nicosulfuron. For isoxaflutole applied at 120 g ha^-1 Balu hybrids were more tolerant than Embrapa hybrids.