Sudden Death Syndrome in Soy — Biggest Threat to the Entire Food Chain?

This past week we received an interesting e-mail about something called “sudden death syndrome” which we were asked to blog about.  Here’s the article we were sent.  We don’t always take requests, but we thought that this was an interesting one, so we decided to write a little post about it.  Sudden death syndrome is basically a fungal disease which affects the roots of soybeans.  Recently there has been some press out there about how Round-up ready soybeans are particularly susceptible to this disease and that the spraying of roundup itself can lead to favorable environments for it.

This is a particularly attractive disease for a number of groups because it  provides fuel to their fire.  The anti-biotech group likes it because it makes Round-up ready crops look bad, the anti-pesticide group likes it because it makes pesticides look bad, the anti-Big Ag group likes it because it makes Monsanto look even more evil than usual.  So, in short, lots of happily indignant people.

So is it true?  Is using Round-up and Round-up Ready Soybeans a sure way to condemn ourselves to a soyless future?  On a side note this is something I really care about – I am a chronic soy sauce user.  If something is good without soy sauce it then it is going to be even better with it.  Well, I spend most of Monday and Tuesday looking through scientific articles and here, in a nutshell, is what I came up with:

Sudden death Syndrome is certainly real, and it can devastate a field.  It was around before Round-up and it will be here after Round-up is gone.  The biggest factor in whether it will be a bad year for SDS is the weather.  So what about the Round-up connection?  This is something that has been looked at by researchers, and here’s what they find.  In terms of the fungus responding well to Round-up –  some studies show that it does – most that it doesn’t.  Round-up Ready varieties of soybean may be resistant or non-resistant to SDS and, of course, the non-resistant varieties won’t fare as well as the resistant varieties if SDS is present (it seems possible that this is where the whole hullabaloo started — a field full of Round-up Ready soy but which wasn’t resistant to SDS contracted the disease while nearby non-Round-up Ready soy which did happen to be resistant to SDS did fine.)

Now there are some studies, mostly in test-tubes and greenhouses, which show that Round-up could make SDS worse, but in the field, where it actually matters, there just aren’t that many studies which show a correlation between using Round-up Ready soybeans and SDS — and more studies that show that there isn’t a correlation.  What it all comes down to is that there is a possible relationship between Roundup and SDS, but, despite a lot of research (both government and industry dollars flow easily to agronomic crops), this link isn’t crystal clear and may not exist at all.

10 thoughts on “Sudden Death Syndrome in Soy — Biggest Threat to the Entire Food Chain?”

  1. I was also asked about the connection between SDS and glyphosate earlier this week. The first thing I noticed is that the information is coming from the Institue for Responsible Technology. Go to their website, click on ‘about us’, and you’ll find this: “IRT’s Campaign for Healthier Eating in America mobilizes citizens, organizations, businesses, healthcare professionals, and the media, to achieve the tipping point of consumer rejection of GM foods.” It seems they’re not out to find truth, their goal is to fit information to their truth. I’m not saying such sources should be disregarded, but it’s important to dig deeper in a search for truth.

  2. It’s not just about soy sauce. If all those acres of soybeans just went to soy sauce, we’d be bathing in it. The soy oil extracted from those beans is a major source of food oil and the meal leftover is a major source of high-protein livestock and poultry feed. So if this is a problem, it will affect meat, dairy, poultry and egg prices. What wit
    h $7/bushel corn (the other major component of livestock feed), it would behoove us to make sure that a good portion of our soybean acreage be planted to resistant varieties.

  3. What else is going on in the soil where these soy beans are growing? And is Roundup being used year after year after year in the same fields (most farmers I know would rotate the chemicals used just so as to prevent resistance issues, something I think would be hard to do with the Roundup-ready plants)?

    Thank you for making the distinction between research done in the lab versus in the field–what happens in the field can change conditions dramatically.

  4. Well, there has been considerable research showing the effect of glyphosate upon the rhizosphere and plant immunity.
    Purdue U. identifies the Soy Sudden Death Syndrome as Fusarium Salani. Don Huber, former plant pathologist at Purdue U, found Sudden Death Syndrome where glyphosate had been used to kill plants in the same planting area, but plants where no glyphosate had not been used, were free of the disease.
    Dr. Mae Wan Ho cites studies demonstrating the increase in pathology with glyphosate use.
    Dr. Meriel Watts, the Pesticide Network Asia and the Pacific describes in detail the deleterious effects of glyphosate.
    It is sad that our U’s are dependent upon monies from corporations such as Monsanto. Will we kill all of our microorganisms before we understand the interdependency of our living world and the true costs of chemical toxicity?

  5. Patricia, I’m aware of all of the points that the scientists you mention have made. As a plant scientist I’ve read their work and the work of many others who actually work with cropping systems. In a nutshell, the people who you mention are much more activist than scientist at this stage of their careers. That doesn’t make them wrong of course, but when you look at the case against glyphosate it just isn’t particularly convincing in this instance — not to say it never will be of course — and not to say their aren’t other problems with glyphosate because their are. In terms of understanding chemical toxicity and microorganisms — I worry about that too, but as scientists it’s important to respond in a measured way which appreciates the data rather than reacting emotionally.

  6. Jeff,
    The hypothesis that heavy glyphosate use is associated with sudden death syndrome recently gained more support in research by Iowa State University scientists. See They note the sharply increased use of glyphosate on soybeans since 1996 (average rate/year has more than doubled), and how it is partly attributable to glyphosate-resistant weeds. They also note this research supports earlier work they did 12 years ago. Many studies that purport to show no adverse effects of glyphosate on soil microbiota look at glyphosate applied to surface soil, whereas the real issue is the impact of glyphosate exuded from the roots of Roundup Ready crops on root-associated microbiota. This is the critical zone where microbes interact with plants, some helping them absorb critical nutrients and others infecting the plants and causing disease. Bob Kremer at University of Missouri has established in decade-long field tests that Roundup Ready crops have increased Fusarium colonization of their roots, and Sudden Death Syndrome as well as other diseases are caused by various species of Fusarium fungi. Other researchers have established that glyphosate kills plants IN PART by promoting infection of the plants with pathogens (it takes a much higher rate of glyphosate to kill plants in sterile soil, because such pathogens are absent). Other research shows that glyphosate can adversely impact the Roundup Ready crop’s uptake of key nutrients, such as manganese, under certain conditions. You say you looked at many studies, and they were inconsistent. That may well be because glyphosate has adverse impacts under some but not all conditions (e.g. manganese deficiency in soils with lower manganese levels). As you say, wet conditions favor SDS. Glyphosate might well exacerbate SDS under wet conditions, and have little or no effect under dry conditions. “Inconsistency” is no reason to dismiss studies, since impacts under certain circumstances are no less damaging by virtue of the fact that they do not ALWAYS occur in ALL circumstances.

    Frankly, Jeff, your shallow comments on glyphosate research put you in the ranks of “pro-biotech,” “pro-pesticide” academic “activists” who are unwilling to objectively consider the science, but rather reflexively defend your favorite technology (Roundup Ready) and pesticide (Roundup).

    It is unfortunate but true that USDA and other branches of government are similarly biased — so committed to promoting biotechnology that serious research into critical questions like glyphosate-SDS do NOT get the funding they deserve, because the findings may not reflect well on this politically favored technology.

  7. Hi Bill, I read the article which you linked to, and found it interesting, but not compelling. Look, as a researcher confronted with a controversial issue it’s my job to look through many articles and assess what I think the research says. Based on what I’ve read, including the information that you provide above, I just don’t see strong evidence that SDS is heavily influenced by glyphosate use, though I certainly see enough evidence to indicate that it may be a factor in some circumstances — and I indicated that in my article above. You obviously require a lower threshold of evidence before you’ll consider something a danger. I am sorry that you feel my honest assessment of the situation makes me “pro-pesticide”, and an academic “activist”, but I am confident in saying that I have truly and earnestly attempted to provide the most objective assessment that I can — Pl
    ease note that I make no claims to being a specialist in this field. And it seems to me that you’re being a little “sour grapes” because my assessment doesn’t match up with yours.

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