A noxious weed that reduces crop yields between 10 per cent and 44 per cent has made its way into Western Canada.
Already damaging crops in Ontario and most of the U.S.A., tall waterhemp has been found in Manitoba.
Tall waterhemp has been found in four fields in southeastern Manitoba. In one field, 30 acres had to be destroyed to control the weed.
What makes this weed particularly difficult for farmers is its resistance to glyphosate and some other groups of herbicides and the prolific seed development.
One plant will produce 250,000 seeds and up to one million in ideal conditions.
The plant grows four or five feet tall but can reach 10 feet.
Tall waterhemp is a noxious weed that must be destroyed no matter where it is found, but that can include hand weeding within crops where practical, Manitoba Agriculture weed specialist Tammy Jones said.
“One or two plants in one year can be thousands of plants the next year,” she said. “It’s really aggressive. It’s terrifying.”
She urged farmers to monitor fields. In early stages the waterhemp looks like redroot pigweed, only growing a lot faster and taller.
Waterhemp has a smooth stem in contrast to redroot pigweed which has a fuzzy stem. Waterhemp leaves are oval or spearhead shape and appear waxy.
Two cases of tall waterhemp were found in Manitoba in 2017 with one plant found last year.
Officials suspect more cases exist in Manitoba.
Ron Walter can be reached at [email protected]
