Don M. Huber, Professor Emeritus of Purdue University writes a letter to Vilsack regarding his concerns about glyphosate.
This cover letter is provided to explain the reasoning and concerns that were conveyed in a letter which I sent to Secretary of Agriculture, Thomas Vilsack on January 17, 2011 (Attachment 1). The letter was not intended for public distribution; however, the letter was ‘leaked’ and subsequently posted on the internet from which it soon became public knowledge world-wide. Once it was widely distributed, I gave permission for subsequent postings in order to keep it consistent. My busy meeting and travel schedule has delayed getting further information on this matter out publicly to the many individuals who have requested it. The scientific data on this newly recognized organism is being prepared for formal publication.
I wrote the letter to Secretary Vilsack for a very simple reason: we are experiencing a large number of problems in production agriculture in the U.S. that appear to be intensified and sometimes directly related to genetically engineered (GMO) crops, and/or the products they were engineered to tolerate – especially those related to glyphosate (the active chemical in Roundup® herbicide and generic versions of this herbicide). We have witnessed a deterioration in the plant health of corn, soybean, wheat and other crops recently with unexplained epidemics of sudden death syndrome of soybean (SDS), Goss’ wilt of corn, and take-all of small grain crops the last two years. At the same time, there has been an increasing frequency of previously unexplained animal (cattle, pig, horse, poultry) infertility and spontaneous abortions. These situations are threatening the economic viability of both crop and animal producers.
Incidence of high infertility and spontaneous abortions in the various animal species is becoming more common. Often, all previously known causes of these conditions can be ruled out as factors for these particular farm operations (Attachment 2). Detailed examination for the newly recognized organism has shown its presence in all of the cases examined to date. Koch’s postulates have been completed for animals to verify the cause/effect relationship with this newly culturable organism. A search for the source of animal infections revealed a high population of this newly discovered electron microscopic sized organism in soybean meal and corn products. The organism appears compatible, and probably synergistic, with other microorganisms such as Fusarium solani fsp. glycines, the cause of SDS of soybeans and also with gram positive bacteria. The organism also is in a very high population in Goss’ wilt infected corn caused by the gram positive bacterium Clavibacter michiganensis subsp. nebraskensis.
Although most corn hybrids have been genetically resistant to Goss’ wilt, preliminary research in 2010 demonstrated that the application of glyphosate herbicide, or the surfactant from glyphosate formulations, nullified this resistance and rendered them fully susceptible to this pathogen (Fig. 1). This disease was commonly observed in many Midwestern U.S. fields planted to RR corn in 2009 and 2010, while adjacent non-GMO corn had very light to no infections in spite of the high inoculum present in no-till crop residues (Figure 2). The increased Goss’ wilt in 2010 was a major contributor to the estimated almost one billion bushels of corn ‘lost’ last year (based on USDA August estimated yields and actually harvested crop reported by USDA in January) in spite of generally good harvest conditions.
Increased severity of plant diseases after glyphosate is applied (Fig. 3) is well documented and, although rarely cited, the increased disease susceptibility is the herbicidal mode of action of glyphosate (Johal andRahe,1988, 1990; Johal and Huber, 2009; Schafer et al, 2009, 2010). The loss of disease resistance in Roundup Ready® sugar beets when glyphosate was applied prompted researchers at the USDA sugar beet laboratory to include a precautionary statement in their paper, e.g. “Precautions need to be taken when certain soil-borne diseases are present if weed management for sugar beet is to include post-emergence glyphosate treatments” (Larson et al, 2006).
The loss of genetic resistance in Roundup Ready® corn hybrids to Goss’ wilt (Clavibacter michiganensis subsp. nebraskensis) (Figs. 2, 3), synergistic relationship of the newly recognized electron microscopic organism causing infertility and abortions in animals with gram+ bacteria, and high populations of the new EM organism in RR corn leaves and silage creates a concern for the deregulation of Roundup Ready® alfalfa which is productive in many areas only because of its genetic resistance to bacterial wilt caused by Clavibacter michiganensis subsp. insidiosum. This disease could make alfalfa unprofitable for production and, if the EM organism is associated with it in alfalfa as it is in corn, also unsafe for animal feed and their products such as milk for human consumption. The loss of alfalfa, the United State’s most valuable forage crop and fourth most economically important crop, could strike a mortal blow to struggling dairy and beef operations.
Extensive research has shown that this potent tool for weed management, glyphosate, is also a strong immobilizer (chelator) of essential plant nutrients to impair nutrient uptake, translocation, and physiological efficiency at only a fraction of the labeled herbicidal rate (Ekers, Ozturk, Cakmak, Zobiole, Jolly et al., 2004). Glyphosate is a powerful biocide to harm beneficial soil organisms important for nutrient recycling, N-fixation, nutrient availability, and natural disease control (Kremer & Means, Zobiole et al, Dick et al) with a resultant increase in diseases of corn, soybeans (Fig. 3), wheat and other crops. The close relationship between mineral nutrition and disease severity is well documented (Datnoff et al, 2007). These activities can have deleterious effects on plant nutrition, disease susceptibility, and nutritional quality of the crop produced.
Deleterious effects of GM crops also are vividly demonstrated in reports from livestock producers in the U.S. Although some of these reports are anecdotal because of limited analytical techniques to verify the cause, some producers have been able to resume economical operations by changing feed sources to non-GMO crops. Replicated independent research is needed in this area, especially in light of the serious toxicological concerns raised recently that show potential human and animal toxicity from very low levels of residual glyphosate in food/feed that are many times lower than permitted in U.S. food and feed products (Seralini et al., 2011). The recent Indian Supreme Court’s independent analysis and Ruling that GMO egg plant posed a significant health risk to humans needs further evaluation in the U.S. (AgroNews, 2011).
I feel I would be totally irresponsible to ignore my own research and the vast amount of published research now available that support the concerns we are seeing in production agriculture, without bringing it to the attention of the Secretary of Agriculture with a request for him to initiate the much needed independent research. Many producers can’t wait an additional 3-10 years for someone to find the funds and neutral environment to conduct such critical research (Attachment 2. Entomologists letter to EPA).
Based on the scientific evidence currently accumulating, I do not believe it is in the best interests of the agricultural producer or consuming public for regulatory agencies to approve more GMO crops, particularly Roundup Ready® alfalfa and sugar beets, until independent research can establish their productivity when predisposed to potentially severe diseases, the irrelevance of the new EM organism, and their nutritional equivalency. In my letter, I asked the Secretary to allocate the necessary resources to do this, and requested that he exercise the utmost caution in deregulating these crops until such findings resolve the concerns expressed in the letter, if they do.
Don M. Huber
Professor Emeritus, Purdue University 17/1/2011
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