Competitiveness and adaptability of Palmer amaranth in changing Minnesota climate

photograph of palmer amaranth growing in an agricultural field with deciduous trees in the background

Palmer amaranth (Amaranthus palmeri) competing in an agricultural field

Image credit: "Palmer Amaranth in the Field" by United Soybean BoardCC BY 2.0



Palmer amaranth (Amaranthus palmeri) is the most problematic weed in row-crop production in the US. It was first reported in Minnesota in 2016. Because the species is on the Minnesota Prohibited Noxious Weed Eradicate list, it has not been feasible to conduct field experiments, and there is a lack of information about how the species adapts and competes in Minnesota which would inform management strategies. This is further underscored by climate change as Minnesota experiences wetter springs, more common flash floods, and drought in summer.

Palmer amaranth is receiving some competitive challenge from its native relative, waterhemp (Amaranthus tuberculatus). Waterhemp is well-established in Minnesota. The two species have many biological and physiological commonalities, however there is limited data on their relative competitiveness when they coexist, especially in the same climate.

Research question

  • How do changes in precipitation/soil moisture influence the emergence and growth of Palmer amaranth?

Practical implications

This research will generate important information on the adaptability of Palmer amaranth to current and future rainfall patterns in Minnesota and build a foundation for future research. The information gained will help land managers choose the most effective management options in the future.

Research team

Debalin Sarangi | principal investigator

Roger Becker | co-principal investigator

Gregg Johnson | co-principal investigator

Vasudha Sharma | collaborator


Collaborating organizations

UMN Extension

Minnesota Department of Agriculture