Brazil researchers inspect glyphosate resistance claims
Brazilian researchers are analysing samples to confirm reports of glyphosate herbicide resistance in horseweed (Conyza spp) in the state of Mato Grosso. Analysts have teamed up from the agricultural research corporation, the Embrapa, and the Mato Grosso soybean grower association, the Aprosoja, following resistance reports from maize and soybean growers in the state. Samples are being taken from the farms in which the reports have emanated. Embrapa researcher Alexandre Ferreira is among the teams, and notes the potential for resistance while cautioning that poor use of products may also be the cause of control failure. “We have a report this year from a grower in Primavera do Leste of the presence of resistance from the weed in the area, and it deserves special attention,” he says. Horseweed resistance to glyphosate has already been confirmed in the US.