Recently, an Ontario landowner and his agronomist noticed a “weird looking pigweed” along one of their fields and brought the sample to the Department of Plant Agriculture. Dr. François Tardif and Mike Cowbrough identified the plant as Palmer amaranth. Plant material was subsequently provided to TurnKey Genomics, which confirmed this visual identification with a DNA test.
“I think we all knew that it was only a matter of time before this weed reared its head on farms in Ontario,” says Mike Cowbrough, weed specialist, field crops, Ontario Ministry of Agriculture, Food & Rural Affairs (OMAFRA).
“The good news is that there only appears to be the one plant but the area will be scouted again this fall to look for more. I believe the most productive thing that can be done at this time is to gain familiarity with the key identifying features of this species so that any additional sightings can be dealt with before any seed is produced and spread.”
This article is meant as a heads-up for the agriculture community to keep a look out and learn the key identification features of Palmer amaranth.
“Right now there are no implications for horticulture growers, because only one plant was found on a mixed cash crop and livestock farm in Wellington county,” says Kristen Obeid, weed specialist-horticulture, OMAFRA. “At this point there is no evidence that it’s a problem that would require changes to management planning”.
Keep your identification guides handy. If you find a weird looking pigweed plant, contact Kristen Obeid or Mike Cowbrough to obtain visual and genetic confirmation.
Source: Mike Cowbrough, Kristen Obeid, OMAFRA, August 28, 2023