Poisonous weed found in Alberta canola fields

Devil’s trumpet is highly poisonous, but poses little risk when processed into canola meal or oil

Poisonous weed found in Alberta canola fields
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There’s still more questions than answers after a highly toxic prohibited weed was found in canola fields in three counties in north-central Alberta.

Devil’s trumpet — also called jimsonweed — has been confirmed in Barrhead, Leduc, and Westlock counties, but how it got there and how widespread the problem is remains a mystery.

“It would only be complete speculation on my part,” said Curtis Rempel, vice-president of crop production and innovation for the Canola Council of Canada.

“I have no idea what the distribution is like in other fields in the area. The best thing I can say right now is that we’re studying it and trying to figure out how we got to where we are at right now.”

The common denominator seems to be fields seeded to canola this year and last, but that has yet to be confirmed.

“Where we’re finding it right now is in canola. They’re trying to verify where the seed has come from, but nothing is confirmed yet,” said Barrhead County’s agriculture fieldman Marilyn Flock, adding devil’s trumpet has been found in two fields in the county as of Sept. 8.

“Producers should check fields from last year that had canola in them. Even if it’s not into canola this year, still keep a lookout if the field’s in wheat or another crop.”

It’s the same story in Leduc County, where the weed was found in one field, and Westlock County, where four fields have been affected.

“It has been found in canola fields, but it has also been found where canola was grown in 2014,” said Jacolyn Tigert, manager of agricultural services for Westlock County.

Alberta Agriculture and Forestry and the Canadian Food Inspection Agency are investigating how the weed seeds got into the fields, said Rempel. Neither Alberta Agriculture nor the CFIA were available for comment at press time.

Producers should “look for the distribution” of weeds if they find devil’s trumpet in their fields, said Rempel.

“Are you finding it in one pocket in a low spot? Are you seeing it fairly infrequently but in an even distribution across the field? Does it look like it was blown at an angle across parts of the field? Does it look like it moved in with a rainfall event or corner flooding? Are there lots of plants clumped in an area or is it very sporadic?” he said.

“That would give us a good indication (of where it came from.)”

Easy to spot

Devil’s trumpet is “a very easy plant to identify” because of its height, said Tigert.

“The plant is very tall. It’s typically around four to six feet, so right now, it’s above the canopy of the crop,” she said. “Producers are picking it out very easily.”

The plants have thick red or purple stems, with large pointed leaves and white and purple trumpet-shaped flowers. The seed pods are egg shaped and spiny, and each plant has between 20 and 40 pods.

Each pod contains up to 700 seeds, which could cause serious problems if the weeds reach maturity.

“The main concern right now is the maturity of the plants. The seed pod could mature, explode, and spread the seeds,” said Tigert.

Producers need to “catch it right now to nip it in the bud,” said Flock.

“It may be only a few plants, but if the seed pods mature and explode, now you’ve got 600 or 700 seeds per pod, so you want to try to get it before you have that seed source,” she said.

“Sometimes if you bury that seed, it can last in the ground for up to 20 years. Hopefully, you can get them out before you have more plants that produce mature seeds.”

Highly poisonous

Devil’s trumpet is highly poisonous to both livestock and humans if ingested or inhaled.

“It’s very dangerous because low levels of it can result in death for livestock and humans,” said Tigert.

But it poses “very, very low risk” when processed with canola, said Rempel.

“The views of the Canola Council at this point in time are that there wouldn’t be concerns, just based on dilution factors,” he said. “We don’t know how much of the weed seed would actually be in a canola shipment if it’s been lying in a swath for three weeks, but based on the fact that the pod likes to explode fairly quickly, I would think that the risk would be reduced.”

As well, the heating process in canola oil and meal processing denatures toxic alkaloids, so there isn’t a health concern in processed canola products, he said.

Because all parts of the plant are poisonous, producers should exercise extreme caution when handling it.

“Go out in gloves and a long-sleeved shirt, hand pull it, and bag it right away. That’s the best line of defence right now,” said Tigert.

“From there, it should be taken to the landfill, and it can be buried.”

The plants can also be incinerated, but do so carefully, cautioned Flock.

“You want to make sure you’re not breathing in the smoke.”

Producers should report any suspected sightings of devil’s trumpet or any other unidentified weed to their agriculture services board or municipal fieldman.

“As with any plant that they don’t recognize, they should have somebody either come out and look at it, or pull it up with gloves on, put it in a bag, and bring it in so people can identify it for them,” said Flock.

“If you don’t recognize it, it’s better to find out what that stuff is before it becomes a major problem for you. It’s better to be safe than sorry.”

But at this point, producers shouldn’t panic, said Rempel.

“We don’t want to overreact. We don’t want to underreact,” he said.

“We want to keep everything in perspective and contain the weed in the fields that we find it in. We’re looking at containment and control and careful management going forward.”

About the author


Jennifer Blair

Jennifer Blair is a Red Deer-based reporter with a post-secondary education in professional writing and nearly 10 years of experience in corporate communications, policy development, and journalism. She's spent half of her career telling stories about an industry she loves for an audience she admires--the farmers who work every day to build a better agriculture industry in Alberta.



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