ngin - Norfolk Genetic Information Network

11 January 2003


Two more U.S. articles on Roundup weed resistance problems + an article on the threat to Canada from GM wheat.

The first article contains some fascinating detail on the ever growing range of weed problems being experienced with Roundup (glyphosate). The second is rich in biotech hype. For instance, we read about RR soya that "Roundup makes it easier and cheaper to control the weeds. Ron Heck of Perry, Ia., says he used to spend $20 to $40 an acre on weed control. Now the cost is down to about $15 an acre"

But a May 2002 US Department of Agriculture report looking at the latest economic data on 'The Adoption of Bioengineered Crops' shows, "The adoption of herbicide-tolerant soybeans does not have a statistically significant effect on net returns." [p23 of the USDA report]

The report also notes that an analysis using broader financial performance measures also did not show GE crops to offer significant benefits [p23]

And it concludes that: "Perhaps the biggest issue raised by these results is how to explain the rapid adoption of GE crops when farm financial impacts appear to be mixed or even negative." [p24 of USDA report]
A separate study funded by Iowa State University provides the answer. It showed over half the farmers planting herbicide-tolerant GM soya did so because they believed that it gave them higher yields compared to conventional varieties. But when the university analysed the harvest results of the farms concerned they found the opposite was true - GM soya yielded less, a fact widely confirmed by other studies.

In other words, U.S. farmers appear to have been conditioned in their choice of products by industry hype in a similar way to U.S. teenagers in their choice of sports shoes.

Now they're reaping the whirlwind.



December 12, 2002
Plant Health Progress

First it was horseweed (marestail) in Delaware, confirmed resistant two years ago to glyphosate-based herbicides such as Touchdown® and Roundup®. Then the same weed proved resistant in Tennessee, spreading to about 500,000 acres this year, and Ohio researchers say as many acres are likely infested between southwest Ohio and south central Indiana.

Now, at least one weed scientist is ready to add waterhemp to the list of glyphosate-resistant weeds.Iowa State University researchers have tested waterhemp plants from a number of locations around the state. Individual selected plants survived an average of 2.6 times the labeled rate of glyphosate, with some plants able to shrug off even higher rates.

Mike Owen, extension weed management specialist with Iowa State University, says there's enough evidence for him to label these individual weeds resistant.

"Our work demonstrates that the glyphosate resistance in these waterhemp plants is heritable," he says. "It's passed on from one weed generation to the next, although the exact mechanism and frequency is still unknown. We do not feel that there is a major concern for glyphosate resistance in waterhemp at this time."

In similar waterhemp studies conducted by Reid Smeda, weed scientist with University of Missouri, waterhemp plants from Missouri and Illinois survived up to eight times the labeled rate of glyphosate. For now, Smeda is calling these weeds "insensitive" to glyphosate. "It's more than a natural tolerance, but we don1t have enough evidence yet to call it resistance", he says. "Even if we're not saying resistance, we're not controlling waterhemp as well as we did six years ago," adds Bryan Young, assistant professor of weed science at Southern Illinois University. "We're using higher rates of glyphosate and more applications."  Regardless of semantics, says Owen, the problem in a grower's field is the same: "You can't kill the weed with the labeled amount of glyphosate."

Roundup Ready System at Risk

For most growers in the 2003 season, the waterhemp and marestail problems may not amount to anything more than a chink in the armor of glyphosate, the largest selling herbicide in the U.S. and the world. But weed scientists in the Corn Belt say glyphosate resistance will spread, and growers should take steps now to manage it. Resistance could spoil the effectiveness of Roundup Ready (RR) technology, which is now used on about 75% of the soybeans in the U.S.

It was only a few years ago that waterhemp developed resistance to the most popular soybean herbicides at that time, a family of chemistry known as ALS-inhibitors. The timing coincided with the introduction of RR soybeans, which quickly eclipsed ALS-inhibitors and solved the problem - at least for a while.

This time around, however, there's no major new technology waiting if a problem develops.

"There's no new silver bullet around the corner," says Owen. If glyphosate fails, the only alternatives will be older herbicides already on the market, different management tactics, and mechanical control strategies. "Without glyphosate in the arsenal for waterhemp, we would go back to narrower windows of application, intensive scouting, and tank-mixing," says Tom Hoverstad, weed scientist at the University of Minnesota. "We would be evaluating crop injury versus control, and if our conventional herbicide didn't work, we wouldn't always be able to apply it again." One piece of good news: weed experts say that because of the way the weed reproduces, resistant waterhemp isn't likely to spread as rapidly as horseweed has. Also, most growers in the Midwest grow RR soybeans but not RR corn, so they're rotating herbicide modes of action annually. That's one real key to preventing or slowing the spread of resistance. Horseweed (marestail) spread from a few fields in Tennessee in 2000 to an estimated 500,000 acres in Tennessee and Kentucky in 2002. On the East Coast, glyphosate-resistant horseweed spread from six Delaware fields to over 50,000 acres in Delaware, Maryland, Virginia, and New Jersey - all in the same three-season span.

In Ohio, extension weed specialist Jeff Stachler is now reporting glyphosate-resistant horseweed. "We have nine populations from four counties in southwest Ohio surviving four times the labeled glyphosate rate," says Stachler. The glyphosate-resistant horseweed is also in Indiana, halfway between Indianapolis and the Ohio River. He1s calling for strong resistance management tactics.

Resistance vs. Weed Shifts

Likewise, Hoverstad says he's seeing more waterhemp than ever before in Minnesota. "Velvetleaf also seems to have an edge over glyphosate," he notes. "But this is probably the result of weed shifts and not true resistance." Like resistance, weed shifts are caused by repeated glyphosate use. But there's no genetic change in the weed population, just a build-up of weeds that are naturally more tolerant to glyphosate chemistry.

"Glyphosate has never been as consistent on weeds like black nightshade, yellow nutsedge, and velvetleaf," says Bob Hartzler, weed management specialist with Iowa State University. "In a RR system where you're relying heavily on glyphosate and little else, these weeds can survive, produce seed, and increase in density."

In Ohio, dandelion is a good example. Stachler reports that it's gone from a minor weed to a major problem on just about every acre of no-till soybeans.

"It's even hard to control it with two tillage passes," he says. He's also seeing a shift to common lambsquarters in RR soybeans, where glyphosate no longer gives consistent control of the weed. Dallas Peterson, weed specialist with Kansas State University, says he is seeing more morningglory where farmers grow continuous RR soybeans. Like his counterparts in Ohio and Minnesota, he says this is more of a weed shift than resistance. "But the end result is the same," he notes. "We're left with a weed that our current program no longer controls."

What Causes Resistance?

Researchers say the culprit in glyphosate resistance and weed shifts is continuous use of glyphosate in Roundup Ready cropping systems. In Tennessee, it's continuous RR cotton, or RR cotton rotated with RR soybeans.

In Delaware, it's continuous RR soybeans. These rotations allow for glyphosate use every year, with few if any other herbicides in the rotation.

"In the Corn Belt there hasn't been as much continuous glyphosate because many growers have been rotating RR soybeans with conventional corn," says Hartzler. But an increase in RR corn threatens to upset that balance.

Introduced in 1999, RR corn took off slowly, but Hartzler says it1s gaining popularity in pockets of the Corn Belt, especially where corn is grown for domestic use instead of export.

"If farmers keep planting more RR corn, we'll be in a continuous glyphosate situation too," Hartzler says. "Granted, many farmers would probably use a pre-emergence treatment on RR corn and that would offer us some protection against resistance, but probably not enough. There would still be a lot of selection pressure."

Rotate to Fend Off Resistance

Despite the potential consequences of resistance, researchers say resistance management is a tough sell with some growers. They like the simplicity of Roundup Ready technology and want to use it every year. Many figure they'll make a change after resistance becomes a problem. But once that happens, the damage is already done.

"Once you apply glyphosate or any herbicide, the clock starts ticking," says Smeda. "If you want to protect the chemistry, you must be proactive." The only way to preserve glyphosate is to avoid overusing it, says Hartzler. He advises growers who plant RR soybeans to avoid RR corn, and vice versa.

"It's just too easy to fall into a trap of overusing glyphosate when you're growing one RR crop after another," says Bryan Young, assistant professor of weed science with Southern Illinois University.

KSU's Peterson agrees. "If you're relying heavily on glyphosate in RR soybeans, then we encourage you to use conventional weed control systems in corn," he says.

Rotation figures heavily in resistance management guidelines issued by Syngenta for growers using glyphosate-based herbicides - including Syngenta1s Touchdown, which is commonly used in RR crops.

"We're advising growers to use no more than two applications of Touchdown or any other glyphosate-based herbicide over a two-year period," explains Chuck Foresman, technical brand manager at Syngenta. "If they're using two sequential sprays on RR soybeans or corn, then we recommend using conventional seed and herbicides the following year."

Corn vs. Soybeans

Which crop should be Roundup Ready? Hartzler leans toward soybeans.

"First, growers are already using RR technology in soybeans but most haven't started yet in corn," he says. "Second, we have good alternatives for waterhemp control in corn, but there is no existing chemistry or new chemistry in development that would give us the same flexibility for controlling waterhemp in soybeans."

Corn is also more susceptible to early-season weed competition than soybeans, notes Hoverstad. That makes post-emergence glyphosate weed control a better fit for soybeans.

For now, weed specialists say the biggest challenge will be convincing growers to use less RR technology instead of more. "We can't keep using glyphosate until it doesn't work anymore, because there's nothing else out there," concludes Stachler. "It's essential to start addressing resistance problems now -- before we wind up with super-weeds."



Des Moines Register, Washington Bureau, Jan. 10/03

Washington, D.C. - Few inventions, according to this story, have altered agriculture recently as much as Roundup weedkiller, but now scientists are concerned that farmers are using the herbicide so heavily it is losing its effectiveness against some of the world's peskiest weeds.

Bob Hartzler, a weed scientist at Iowa State University, was quoted as saying, "It's going to happen. It's inevitable."

Known generically as glyphosate, the story says that Roundup is powerful yet environmentally benign. It has led to the widespread adoption of soil-saving techniques that reduce land erosion and combat global warming. Even home gardeners are likely to have a version of Roundup in their garage arsenal.

The story says that Roundup has been around for nearly 30 years but exploded in popularity in the late 1990s with the development of genetically engineered soybeans, cotton and other crops that are immune to the herbicide. That change means farmers can spray their fields with the relatively cheap weedkiller whenever it's needed with no fear it will harm the crops.

Roundup-immune soybeans now account for 75 percent of all the soybeans planted nationwide and in Iowa. Some 33 million pounds of glyphosate were sprayed on soybean crops alone in 2001, a five-fold increase from 1995, according to the U.S. Department of Agriculture.

The story notes that scientists are finding Roundup-resistant weeds in a variety of states, from Iowa to Delaware and that scientists are so concerned that some 200 showed up for a symposium on the issue last month in St. Louis.

Monsanto Co., which invented both Roundup and the Roundup-immune crops, has applied to the Environmental Protection Agency to alter Roundup labels to add special instructions for farmers in areas with resistant weeds.

A rival manufacturer of glyphosate, Syngenta, is advising farmers not to apply the chemical more than twice in every two-year period and not to plant glyphosate-resistant crops in the same field every year.

Economist Charles Benbrook, a critic of the biotech industry and a former executive director of the National Academy of Sciences' board on agriculture, was quoted as saying, "The warning signs are already out there."

The story says that if herbicide-tolerant weeds gain hold, land prices could slip and farmers would be forced to start using additional chemicals, adding to their costs and potentially increasing environmental risks.

No alternatives to Roundup are on the horizon. Industry experts say Roundup has been so effective for so long that there has been no financial incentive for chemical companies to develop a substitute.

Farmers love the bioengineered soybeans because they say Roundup makes it easier and cheaper to control the weeds. Ron Heck of Perry, Ia., says he used to spend $20 to $40 an acre on weed control. Now the cost is down to about $15 an acre, even accounting for the special fee for the seed. Growers also say the biotech soybeans have allowed them to farm more land and spend more time with their families, or in some cases take a second job. Monsanto throws in some more incentives: If the biotech crops fail, the company will refund some of the seed cost. And if the herbicide doesn't kill the weeds, farmers can get additional Roundup for free.

The story says that Roundup is so effective as a herbicide that many farmers are no longer tilling their fields to control weeds. Less tillage means less erosion and stores carbon in the soil, thereby limiting the production of the greenhouse gases blamed for global warming. No-till soybean acreage increased by 35 percent from 1995 to 2000, according to one study.

Herbicide resistance in weeds is nothing new. It happens regularly with weedkillers, except, until recently, with Roundup.

Some of the first significant reports of Roundup-resistant weeds in the United States surfaced in Delaware. Mare's-tail, or horseweed, that could not be killed by the herbicide was found on several farms in 2000.

Scientists were cited as saying they had to spray the weeds with 10 times the recommended rate of the herbicide to kill the plants.

Scientists in Iowa and Missouri have, the story says, found fields with types of waterhemp, a prolific Midwestern weed, that are significantly more tolerant of glyphosate than others. More than a quarter of the weeds collected from one Iowa field survived being treated with Roundup.

ISU scientist Mike Owen was quoted as saying, "Everybody is in reasonable agreement that the evolution of glyphosate resistance in waterhemp is inevitable."

Monsanto, which generates 50 percent of its annual sales from Roundup, says there are two U.S. weeds that are resistant to it - mare's-tail and ryegrass - but company officials say the problem isn't serious. They don't consider waterhemp resistant.

David Heering, who manages the technical side of the Roundup business for Monsanto, was cited as saying rival companies like Syngenta are trying to discourage farmers from using the glyphosate-resistant, or Roundup Ready, crops because they cut into sales of other herbicides, adding, "As we see increased adoption of Roundup Ready, they are going see lost business."

Chemical companies have another reason to discourage use of Roundup Ready crops: Monsanto profits from the special technology fee it charges on every bag of the gene-altered seed. Other companies do not.

Syngenta officials were cited as saying they are trying to ensure that glyphosate, which they market as Touchdown, remains effective.



January 9, 2003
Council of Canadians

OTTAWA, ONTARIO - Concerned with the increasing pressure mounted by the biotechnology industry on the federal government, the Council of Canadians is launching an all-out attack to raise awareness regarding genetically engineered wheat.

The last few weeks have been fertile in biotechnology-related events.

First, Saskatchewan farmer Percy Schmeiser has filed an appeal to the Supreme Court, asking that the Federal Court decision to uphold his guilty verdict in the case opposing him to Monsanto for alleged violation of patent rights on GE canola. Then, the Saskatchewan Organic Directorate filed a $14-million class action suit against Monsanto and Aventis as a result of the largedegree of crop contamination by GE canola.

More recently, Monsanto Canada, a biotechnology company, applied to the Canadian Food Inspection Agency (CFIA) for approval of the environmental release of genetically engineered wheat. An application has also been filed at the same time to U.S. regulators.

Part of these efforts will be a 12-city tour of the Canadian Prairies this winter to raise awareness on the consequences of allowing GE wheat to grow in the country. The launch of the tour is currently set for February 27, in Winnipeg. Spearheaded by the Council of Canadians, the tour will be co-organised by the Saskatchewan Organic Directorate, the National Farmers' Union and the Alberta-based Parkland Institute.

"Approving GE wheat, for example, would have consequences that are not limited to health safety concerns," says Nadège Adam, biotechnology campaigner for the 100,000-member Council of Canadians. "The farmers traditional right to reuse part of the crop to seed the following year is also in jeopardy, as this practice would infringe the patent. And when you think you can go around this problem by switching back to natural seeds, you are faced with a contamination problem that is impossible to contain."

We warned this would be happening with other crops such as canola, and it happened. Why the Canadian government would openly consider opening our wheat crops to such risks is beyond me. There is absolutely no evidence that GE crops have higher yields and are in any way beneficial for farmers.

However, the potential for contamination is so high that the future of organic farming would be truly threatened by the release of GE wheat in the farming community"

Back in 1999, the Council of Canadians was part of a multi-sectoral effort that won a hard-fought and long battle against Monsanto's attempt to have Health Canada approve the Bovine Growth Hormone (BGH) that would have found its way through the milk supply consumed by Canadians.

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