Resistance is showing up in weeds, insects and disease pathogens in Iowa and has the potential to impact yields, increase the cost of production, and limit farmers’ future
pest management options.
Examples of Resistant Weeds
Common cocklebur, common lambsquarters, common sunflower, giant foxtail, giant ragweed, horseweed, Kochia, Pennsylvania smartweed, waterhemp, and recently, Palmer amaranth.
Examples of Resistant Insects
Western corn rootworm (WCR), also soybean aphid populations near, but not yet inside, Iowa.
Examples of Resistant Diseases
Soybean cyst nematode (SCN) and frogeye leaf spot.