Study - GM wheat poses a threat/Scientists eye glyphosate-fusarium link
"scientists in Canada and the United States say there are reasons to be cautious about introducing new technologies such as Roundup Ready crops that might boost the use of glyphosate-based herbicides.
"The biggest thing overall that we've found is that there is a relationship here, mostly causing significant increases in vegetative fungal growth of these plant pathogens" (item 2)
1.Study: Modified wheat poses a threat
2.Scientists eye glyphosate-fusarium link
1.Study: Modified wheat poses a threat
By SCOTT EDMONDS - Canadian Press, July 9, 2003
WINNIPEG (CP) -- Genetically modified wheat poses an unacceptable risk to the environment, says a University of Manitoba study released Wednesday.
"Under current conditions the release of Roundup Ready wheat in Western Canada would be environmentally unsafe," concludes the report by three plant scientists.
The study was commissioned by the Canadian Wheat Board, which doesn't want to see genetically modified grain released for sale. It fears it will damage Canada's ability to sell into export markets where genetically modified crops are shunned.
"The study shows that this product, if granted unconfined release, will cause environmental problems for all farmers, not just those who choose to grow it," said wheat board chairman Ken Ritter.
Roundup Ready wheat is resistant to the herbicide of the same name produced by Monsanto. It allows farmers to spray Roundup on their wheat crop to kill weeds without killing the grain at the same time.
Roundup Ready canola has been on the market for years with the same traits.
"If Roundup Ready wheat was grown under unconfined conditions in Western Canada, the trait would move from wheat crop to wheat crop in a fashion similar to that seen in canola," the report says.
That means farmers would have to use other herbicides which can kill Roundup-resistant plants as well as Roundup, which has become the most popular agricultural herbicide.
Rene Van Acker, Anita Brule-Babel and Lyle Friesen say experiences with genetically modifed canola show there is a huge downside to the unconfined release of Roundup Ready wheat.
"When the Roundup Ready trait moves among canola crops, it becomes impossible for farmers to know if their . . . canola population will contain Roundup Ready volunteers, even if they have not previously grown Roundup Ready canola."
They also say the release of the wheat strain would increase the risk of the development of weeds that are resistant to the herbicide.
Officials at Monsanto Canada, which has applied to have the wheat undergo a federal environmental safety assessment, could not be reached for comment.
But Monsanto Canada president Peter Turner said in a letter to the wheat board three weeks ago the biotechnology company won't do anything to put farmers in jeopardy and wouldn't put the wheat on the market until it wins acceptance in major export markets. He also promised it wouldn't be released until it can be effectively segregated from other wheat in the Canadian grain-handling system.
Monsanta has no target date for introduction of the wheat.
The study is being sent to the plant biosafety office of the Canadian Food Inspection Agency, which is assessing Roundup Ready wheat.
2.Scientists eye glyphosate-fusarium link
Saskatoon newsroom, July 10 2003
The National Farmers Union has come up with another reason to resist the introduction of genetically modified Roundup Ready wheat fusarium.
Appearing before the House of Commons agriculture committee recently, NFU president Stewart Wells said studies linking glyphosate-based herbicides and fusarium are cause for serious concern.
The production of Roundup Ready wheat would result in a dramatic increase in the amount of glyphosate applied during the growing season, he said, which in turn could increase the incidence of fusarium.
"More work needs to be done in this area, but Roundup Ready wheat should not be approved until we understand the links between formulations of glyphosate and fusarium," Wells told the committee.
In fact, the battle over the introduction of GM wheat will almost certainly be determined by issues such as market acceptance and consumer concerns over food safety, rather than by any alleged link between glyphosate and fusarium.
And so far no direct causal link has been definitively established between Roundup and fusarium head blight, which has caused tens of millions of dollars of losses for wheat growers in the eastern Prairies in recent years.
Trish Jordan, manager of public affairs for Monsanto Canada, which manufactures Roundup and is developing Roundup Ready wheat, said that while Monsanto is aware of the concerns, the data gathered so far are preliminary.
"It's important in something like this to look at a full body of research and not to jump to conclusions, as the NFU seems to be doing," she said, adding that Monsanto is not about to abandon its Roundup Ready wheat project over the issue.
But scientists in Canada and the United States say there are reasons to be cautious about introducing new technologies such as Roundup Ready crops that might boost the use of glyphosate-based herbicides.
"There are some linkages here that we need to investigate further," said Keith Hanson, a microbiologist at Agriculture Canada's research centre in Swift Current, Sask.
Laboratory research by Hanson and plant pathologist Myriam Fernandez has shown that applying glyphosate-based herbicides usually stimulates the growth of fusarium pathogens that cause fusarium head blight.
"The biggest thing overall that we've found is that there is a relationship here, mostly causing significant increases in vegetative fungal growth of these plant pathogens," Hanson said.
Those results correspond to field surveys conducted by Fernandez, which found that fields where glyphosate had been applied in the previous year had higher levels of fusarium head blight pathogens and a greater incidence of FHB.
Robert Kremer, a microbiologist with the U.S. Department of Agriculture's research service, has done research showing that Roundup Ready soybeans receiving the recommended application of Roundup have significantly greater colonization of fusarium on their roots than untreated soybeans.
He said in an interview from his office at the University of Missouri that while it's dangerous to extrapolate the situation with soybeans to other crops, there is reason to be cautious about introducing Roundup wheat.
"Probably the first year that it's planted there may not be any problem," he said. "But in subsequent years in the same field there is always the chance that it could trigger an increase in fusarium."
Hanson acknowledged that many questions remain unanswered.
For example, to what extent is the growth of pathogenic fungi in the soil increased by the glyphosate herbicide, to what degree does that translate into the appearance of FHB and what effect does it have on future crops?
There are questions about how different varieties of plants react, whether specific fusarium fungi respond more than others and exactly why the glyphosate herbicides stimulate fusarium growth.
It also appears from Hanson and Fernandez's research that not all glyphosate products have the same effect on the fusarium, leading to speculation that non-active ingredients in the commercial formulation may account for the apparent fusarium link.
"It's not the glyphosate itself necessarily, but the glyphosate herbicide on the whole that is stimulating something in the fusarium species and possibly increasing growth and creating increased populations," Hanson said.
Jordan said there are other possible explanations. For example, Roundup and other glyphosate formulations are used extensively in zero- and minimum-till situations. Since the fusarium fungi survive on wheat crop residues, any cultural practice that results in more residue will also result in more fusarium if other conditions are favourable.
She said Monsanto is aware of the research, but isn't doing any of its own and likely wouldn't unless peer-reviewed studies are published pointing to a definite link.
Hanson said the Swift Current researchers will continue with laboratory and greenhouse work to evaluate the production and viability of fusarium spores under glyphosate application, and then move on to growth chambers to test the effect of glyphosate on infected cereal residues. There are no immediate plans for field-scale studies.