A recent study shows some Palmer Amaranth has built up resistance to another chemical mode of action. Professor Tom Barber is with the University of Arkansas Extension. He says, “We have populations in Arkansas now that we know of or at least five-way resistance. This particular population, we found a couple, actually three fields that were sampled and screened in the greenhouse that are gluphosinate resistant.”
Barber tells Brownfield they have a lot of Palmer Amaranth in Arkansas that is still resistant to five modes of action but not yet resistant to gluphosinate.
