In the last few days, claims of a new pathogen or disease “…that appears to significantly impact the health of plants, animals, and probably human beings” has garnered attention on the internet. The claim has been put forward by Dr. Don Huber, a retired professor from Purdue. In the time since we learned of this, which was brought to light through a “confidential” (i.e., published) letter to Secretary of Agriculture Tom Vilsack, we’ve been asking numerous experts questions about whether they’ve seen any issues. We know of no evidence to support the claim. We also posted a short statement on our website as we asked questions and fielded questions from others.
Trent Loos, a well known broadcaster who seeks to highlight the Faces of Agriculture, surprised us with a commentary Thursday providing the perspective that we have heard in many phone calls. The MP3 from the Faces of Agriculture “Colorado Tales and Trails” feature is provided here. At two minutes into the recording, Loos reads from the letter and asks the rhetorical question, “You tell me what’s wrong with this…” Loos asks where the science is and where problems Huber refers to have occurred? He also suggests a number of other factors that could be considered in a scientific evaluation, and that he wants to contact Purdue University to learn more. Loos wants the facts.
Purdue scientists had also seen the claims and independently considered the facts. A statement issued today by the Agricultural Extension Service of Purdue University, Glyphosate’s Impact on Field Crop Production and Disease Development, directly addresses Huber’s allegations.
This is not a new controversy, but many statements released in recent weeks by groups opposed to the use of genetically modified (GM) crops have claimed that glyphosate use and Roundup Ready® technology will be disastrous and that glyphosate has damaged crop production by decreasing nutrient availability to plants, reducing nutrient content of food and livestock feed, and increasing plant susceptibility to disease…. However, evidence to support these claims has neither been presented to nor evaluated by the scientific community.
…[P]lant pathologists have NOT observed a widespread increase in susceptibility to plant diseases in glyphosate-resistant corn and soybean.
The claim that plant disease has “skyrocketed” due to glyphosate usage is also unfounded. It is also important to note that crop yields have been protected from yield-robbing weeds by many different herbicides for more than 50 years. Use of herbicides has not been linked to yield-limiting disease outbreaks during that time. In fact, glyphosate has been used extensively for more than 30 years and no yield-limiting disease outbreaks have been attributed to glyphosate use prior to these recent reports.
Overall, the claims that glyphosate is having a widespread effect on plant health are largely unsubstantiated [emphasis in original]. To date, there is limited scientific research data that suggest that plant diseases have increased in GM crops due to the use of glyphosate. Most importantly, the impact of these interactions on yield has not been demonstrated. Therefore, we maintain our recommendations of judicious glyphosate use for weed control. We encourage crop producers, agribusiness personnel, and the general public to speak with University Extension personnel before making changes in crop production practices that are based on sensationalist claims instead of facts
We also would be remiss to end this blog without saying thank you to all the farmers and ranchers who have contacted us proactively to say their anecdotal information is consistent with the science cited by so many public universities. We will continue to cast a wide net to discover on what basis these claims were made and keep channels of communication open.