Hey there, time traveller!
This article was published 19/5/2009 (4375 days ago), so information in it may no longer be current.
Winnipeg loses thousands of elm trees every year to the fungal disease spread by the elm bark beetle. Manufacturers of the Dutch Trig vaccine say injecting a tree with the solution cuts its risk of developing Dutch elm disease to one per cent.
"The injections are only good on healthy elm trees," said Joris Voeten, a master arborist with BTL Bomendienst, the Netherlands-based company that makes the vaccine.
Voeten was in Winnipeg today to demonstrate the vaccine, approved for use in the Netherlands and the United States. Health Canada has yet to approve the product, but a spokesman said an evaluation is completed. The agency's proposed decision on the vaccine will be up for public review shortly, he said.
Tests on trees in Kildonan Park and Wildwood Park this summer will help arborists get familiar with the product, said Voeten.
To vaccinate a tree, arborists inject a drop of the solution every 10 centimetres in a ring around the trunk. The vaccine consists of fungal spores and water, and has been deemed non-toxic by the United States Environmental Protection Agency.
"It's a purely biological product," said Voeten.
The vaccine can't help trees that are already infected. And protection doesn't come cheaply. The vaccine costs between $60 and $120 per tree, depending on the number of trees treated. But Voeten said the treatment pays for itself.
"The cost of the vaccine is easily offset by the fact that you don't have to cut down all of those elm trees," he said.
The cost of the trial will be covered by the vaccine manufacturers, who hope for federal approval by May 2010, in time for the next injection season.
City forester Martha Barwinsky said Winnipeg relies on pruning and tree removal to combat Dutch elm disease, as well as fungicide injections of 150 to 200 high-value trees annually. Dutch Trig "would be another tool in our toolbox," she said.
"A biological control is always an asset, and always something to look at," she said.
The city has lost around 4,400 elm trees per year over the past three years to Dutch elm disease, said Barwinsky. On average the loss rate is around two per cent annually.
Winnipeggers worried about the elm trees on their property should keep them healthy by watering and pruning regularly, said Barwinsky, and watch for symptoms like yellowing or browning leaves.
The province and city have spent more than $50 million fighting Dutch elm disease since it arrived here with the elm bark beetle in the 1970s.