WINNIPEG – A common fungus could blanch dandelions out of existence by robbing the pesky weeds of the green-coloured chlorophyll they need to live, Canadian researchers say.
The fungus could replace some chemical herbicides that have been banned because of environmental and health concerns in a growing number of cities, including Toronto.
Scientists at Agriculture Canada found the naturally occurring fungus, called Phoma macrostoma, can be spread on soil to prevent weeds from growing, without harming grass.
“It causes those plants to turn white so they don’t produce any chlorophyll,” said Karen Bailey, a weed pathologist at the department’s research centre in Saskatoon.
Read Also
Canada’s plant hardiness zones receive update
The latest update to Canada’s plant hardiness zones and plant hardiness maps was released this summer.
“If plants don’t produce chlorophyll, they don’t grow, so they die very quickly,” Bailey explained.
The fungi was isolated from sickly Canada thistles across the country. Trials show that spreading the flour-like fungi on freshly planted or clean lawns prevents more than 80 percent of weeds from growing, Bailey said.
“If you’re going to seed a lawn or want to prevent weeds from entering into an area, that would be how it would be used,” she said.
The organisms live about four months in soil before they start to die. By the following year, they are gone.
“We don’t want (the fungi) to really change that microbial balance, because that’s not the only living thing in the soil,” she said.
The department has a three-year research agreement with the Canadian division of The Scotts Co., maker of Miracle-Gro fertilizer and other gardening products.
It gives Scotts the first right to commercialize the fungi if it is found to be safe and economical to produce in large quantities, Bailey said.
Scotts also markets Killex, a synthetic herbicide that uses 2,4-D to kill weeds after they have emerged.
The potential market for the fungi is huge, said Barry Maynard, vice-president and general manager of Scotts Canada Ltd., who did not have projections.
“Whether it’s golf courses or cemeteries or consumer lawns, basically it could have appeal for all those different areas to use the product,” he said.
The fungi could be on shelves in four to six years, Bailey said, if the research continues to show promise.
But first, researchers need to figure out how to formulate, package and store the living organisms, which are sensitive to temperature and moisture.
“It naturally exists in the environment. The challenge is: how do you harness it?” Maynard said.
