Contact the Minnesota Department of Agriculture's feed regulatory program at 651-201-6064 or mda.dfid-complaint@state.mn.us and save any remaining feed.
Heat is the enemy of weed seed survival, so heating the contaminated feed or manure (ideally, to 140F) will kill some of the Palmer amaranth seed. To do this, you might ensile the feed (if appropriate for the feed type) and compost the manure. Keep in mind that even the best heat treatments will leave some remaining viable seeds. Therefore, spread contaminated manure only on fields that you can easily scout multiple times to check for Palmer amaranth. You can find more information and contact on the University of Minnesota's website.
Heat is the enemy of weed seed survival, so heating the contaminated feed or manure (ideally, to 140F) will kill some of the Palmer amaranth seed. To do this, you might ensile the feed (if appropriate for the feed type) and compost the manure. Keep in mind that even the best heat treatments will leave some remaining viable seeds. Therefore, spread contaminated manure only on fields that you can easily scout multiple times to check for Palmer amaranth. You can find more information and contact on the University of Minnesota's website.
Anyone who thinks they have discovered Palmer amaranth should:
- Take clear photos of the plant(s) showing the leaves, stems and flowers/seedheads.
- Record the location, mark the plant with a flag or flagging tape.
- Report it through The Minnesota Department of Agriculture’s Report A Pest website, or call 1-888-545-6684 to leave a voicemail.
- Upload pictures taken of the plant(s), provide the location (latitude/longitude) and, other requested information.
If you are asked to provide a sample for genetic testing, follow these steps.
Contact the Minnesota Department of Agriculture's seed regulatory program by email seed.mda@state.mn.us or call 651-201-6309 and save any remaining seed or screenings.
Contact the Minnesota Department of Agriculture's feed regulatory program at 651-201-6064 or mda.dfid-complaint@state.mn.us and save any remaining feed.
Heat is the enemy of weed seed survival, so heating the contaminated feed or manure (ideally, to 140F) will kill some of the Palmer amaranth seed. To do this, you might ensile the feed (if appropriate for the feed type) and compost the manure. Keep in mind that even the best heat treatments will leave some remaining viable seeds. Therefore, spread contaminated manure only on fields that you can easily scout multiple times to check for Palmer amaranth. You can find more information and contact on the University of Minnesota's website.
Herbicide resistance falls into six herbicide groups for this aggressive weed species (Shyam et al. 2021). The best course of action is to assume that Palmer amaranth is resistant to at least one class of herbicide and diversify your weed management strategies accordingly.
If you have concerns regarding herbicide resistance in Palmer amaranth, please contact the University of Minnesota Extension Crop Production Specialist in your region or discuss with your crop consultant. You can also contact the Minnesota Department of Agriculture Noxious Weed Program. More information is available on the University of Minnesota Extension Herbicide Resistance Management Web Site.
Testing Laboratories
Two labs offer testing to determine if Palmer amaranth plants are glyphosate or PPO resistant: University of Illinois Plant Clinic and National Agricultural Genotyping Center. Contact either lab to learn more about the services they provide and how to properly collect and ship samples. A grow out would be required to test for all the different mechanisms of resistance.
Herbicide resistance falls into six herbicide groups for this aggressive weed species (Shyam et al. 2021). The best course of action is to assume that Palmer amaranth is resistant to at least one class of herbicide and diversify your weed management strategies accordingly.
If you have concerns regarding herbicide resistance in Palmer amaranth, please contact the University of Minnesota Extension Crop Production Specialist in your region or discuss with your crop consultant. You can also contact the Minnesota Department of Agriculture Noxious Weed Program. More information is available on the University of Minnesota Extension Herbicide Resistance Management Web Site.
Testing Laboratories
Two labs offer testing to determine if Palmer amaranth plants are glyphosate or PPO resistant: University of Illinois Plant Clinic and National Agricultural Genotyping Center. Contact either lab to learn more about the services they provide and how to properly collect and ship samples. A grow out would be required to test for all the different mechanisms of resistance.
Herbicide resistant weeds increase the cost of production and require a strategy for management.
Herbicide resistant weeds compete with crops and increase the cost of production because they require new strategies for management. Producers with Palmer amaranth infestations must diversify their weed management strategies and take an aggressive approach to reducing, and if possible, eliminating infestations over time.
- More weeds per acre increases competition with crops for resources and significantly reduces yields – some estimates as high as 70 – 90%.
- Selecting specific genetics and chemistry to control infestations may increase the cost of planting seed and herbicides for control.
- Labor intensive activities need to be implemented including season-wide field scouting, hand pulling, hoeing, cleaning equipment before entering new fields.
- New technologies like drones, spectral imaging, and artificial intelligence are being explored in a variety of applications, but will add cost to modern production practices.
Herbicide resistant weeds increase the cost of production and require a strategy for management.
Herbicide resistant weeds compete with crops and increase the cost of production because they require new strategies for management. Producers with Palmer amaranth infestations must diversify their weed management strategies and take an aggressive approach to reducing, and if possible, eliminating infestations over time.
- More weeds per acre increases competition with crops for resources and significantly reduces yields – some estimates as high as 70 – 90%.
- Selecting specific genetics and chemistry to control infestations may increase the cost of planting seed and herbicides for control.
- Labor intensive activities need to be implemented including season-wide field scouting, hand pulling, hoeing, cleaning equipment before entering new fields.
- New technologies like drones, spectral imaging, and artificial intelligence are being explored in a variety of applications, but will add cost to modern production practices.
Herbicide resistance falls into six herbicide groups for this aggressive weed species (Shyam et al. 2021). The best course of action is to assume that Palmer amaranth is resistant to at least one class of herbicide and diversify your weed management strategies accordingly.
If you have concerns regarding herbicide resistance in Palmer amaranth, please contact the University of Minnesota Extension Crop Production Specialist in your region or discuss with your crop consultant. You can also contact the Minnesota Department of Agriculture Noxious Weed Program. More information is available on the University of Minnesota Extension Herbicide Resistance Management Web Site.
Testing Laboratories
Two labs offer testing to determine if Palmer amaranth plants are glyphosate or PPO resistant: University of Illinois Plant Clinic and National Agricultural Genotyping Center. Contact either lab to learn more about the services they provide and how to properly collect and ship samples. A grow out would be required to test for all the different mechanisms of resistance.
Herbicide resistant weeds increase the cost of production and require a strategy for management.
Herbicide resistant weeds compete with crops and increase the cost of production because they require new strategies for management. Producers with Palmer amaranth infestations must diversify their weed management strategies and take an aggressive approach to reducing, and if possible, eliminating infestations over time.
- More weeds per acre increases competition with crops for resources and significantly reduces yields – some estimates as high as 70 – 90%.
- Selecting specific genetics and chemistry to control infestations may increase the cost of planting seed and herbicides for control.
- Labor intensive activities need to be implemented including season-wide field scouting, hand pulling, hoeing, cleaning equipment before entering new fields.
- New technologies like drones, spectral imaging, and artificial intelligence are being explored in a variety of applications, but will add cost to modern production practices.