Invasive Characteristics and Impacts of Ambrosia trifida

Ambrosia trifida L. is native to North America, has been introduced into many countries in Europe and East Asia, and is also expanding its habitat in its native ranges. Ambrosia trifida grows in sunny and humid environments, such as grasslands, riverbanks, floodplains, abandoned places, and agricultural fields, as an invasive plant species. Ambrosia trifida has a strong adaptive ability to adverse conditions and shows great variation in seed germination phenology and plant morphology in response to environmental conditions. Effective natural enemies have not been found in its native or introduced ranges. The species is allelopathic and contains several allelochemicals. These characteristics may contribute to the competitive ability and invasiveness of this species. Ambrosia trifida significantly reduces species diversity and plant abundance in its infested plant communities. The species also causes significant yield loss in summer crop production, such as in maize, soybean, sunflower, and cotton production. Ambrosia trifida is capable of rapid evolution against herbicide pressure. Populations of Ambrosia trifida resistant to glyphosate, ALS-inhibiting herbicides, and PPO-inhibiting herbicides, as well as cross-resistant populations, have already appeared. An integrated weed management protocol with a more diverse combination of herbicide sites of action and other practices, such as tillage, the use of different crop species, crop rotation, smart decision tools, and innovative equipment, would be essential to mitigate herbicide-dependent weed control practices and may be one sustainable system for Ambrosia trifida management.