Pesticides remain a critical tool for sustainable agriculture

Agricultural pesticides are regularly in the news these days. Whether it’s another court ruling against a pesticide company for contributing to a victim’s cancer diagnosis, a contrary scientific safety review that declares that same herbicide is likely not carcinogenic, or the impacts of a popular class of insecticides on bee populations, it seems that every day we hear more evidence that would support just banning pesticides altogether. That sentiment is shared by many supporters of the “Poison-Free Food & Farming by 2030” campaign. There will be a public event on May 6, 2019 at the Vermont State House to commemorate and gather public support for this pledge.

A move toward banning pesticides as a public policy initiative would be disastrous, and would be counter to the great advances that have been made in food security, environmental protection, and public health in the past five decades since modern pesticide policy began to address the harms caused by unregulated use of pesticides and other agrichemicals, particularly from the 19030s-1960s. In light of legitimate and well-documented environmental and human health problems caused by a lack of pesticide regulation, the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) was passed in 1972 which gave the U.S. Environmental Protection Agency power to license and regulate pesticide sales and use. Almost immediately, several noteworthy pesticides were banned in the U.S. The regulatory system established under FIFRA set science-based limits on pesticide uses and calls for re-review of pesticides at regular intervals. Adoption of the Worker Protection Standard (WPS, passed 1995, updated 2015) and Food Quality Protection Act (FQPA, 1996) continue to refine pesticide policy in the U.S. for the better (Reeves, McGuire et al. 2019).

As a result, pesticides present less of a threat to workers, public health, or the environment than at any time in the last half-century. Pesticide use on a pounds per-acre basis peaked in 1980, and measures of both environmental persistence and toxicity have declined steadily in recent decades (Fernandez-Cornejo, Nehring et al. 2014). Dr. Charles Benbrook, a frequent critic of pesticide use, credited the FQPA with providing “dramatic” reductions in pesticide risk since the 1990s (Benbrook 2012). The WPS and the recent revisions made to it are credited as a “significant step forward to a cleaner, safer and more just environment” for farm workers.

That does not mean that there aren’t potential and real issues with pesticide use in the U.S. However, since the 1970s, substantial effort and investment in Integrated Pest Management (IPM) programs has been expended by state and federal governments, University and other public scientists, industry groups (including agrichemical companies), private consultants, non-governmental organizations, and farmers themselves. IPM is a holistic program that utilizes multiple levels of management including cultural, physical, and biological practices before chemical application to best manage crops and pests, and is the ‘standard’ system used by conventional producers of many crops. The adoption of IPM across the food system in the U.S. deserves credit for the gains that have been made not only in ensuring that pesticides are applied responsibly and with the least non-target impacts, but also with producing the healthiest and most abundant food supply in human history.

There remain many issues with the use of pesticides and other chemicals in agriculture, and everyone along the production and support chains is doing their part to address them. But pesticides are a critically important component to maintaining a safe and affordable food supply while promoting farmer livelihood. Work needs to be done to improve systems, especially in countries where little to no protections or other regulatory instruments to protect workers and the public are available. But despite pest management practices that are used on farms, yield losses of 17-30% are common for staple crops worldwide, with losses greatest in the countries that can least afford to lose that food. (Savary, Willocquet et al. 2019). Without crop protection, including the responsible use of pesticides, we could expect 50-80% losses  from pests for many crops (Oerke and Dehne 2004). That is unacceptable in a modern society, especially when memories of widespread food shortages and famines are only a few decades in our past.

The agricultural systems that produce our food are much refined from the 1950s and 1960s when the conflation of modern farming and cheap, effective, and, yes, often dangerous pesticides combined to rapidly increase food supply and security in the U.S. and worldwide. Fixation on chemicals from 60 years ago blinds us to the incremental progress that has transformed the food supply in that time. Denigrating important tools as “poisons” ignores the protections that have been developed that have increased pesticide safety to workers by several orders of magnitude while essentially eliminating consumer risk from pesticide residues in our food supply. Our farmers and those of us that support them in their efforts deserve better, and the consumers that rely on the safe and abundant food supply available to them deserve facts, and not fear-based messaging.

Benbrook, C. (2012). “Impacts of changing pest management systems and organic production on tree fruit pesticide residues and risk.” Acta Hort 1001: 91-102.

Fernandez-Cornejo, J., R. F. Nehring, C. Osteen, S. Wechsler, A. Martin and A. Vialou (2014). “Pesticide use in US agriculture: 21 selected crops, 1960-2008.” (USDA ERS Bulletin Number 124).

Oerke, E.-C. and H.-W. Dehne (2004). “Safeguarding production—losses in major crops and the role of crop protection.” Crop protection 23(4): 275-285.

Reeves, W. R., M. K. McGuire, M. Stokes and J. L. Vicini (2019). “Assessing the Safety of Pesticides in Food: How Current Regulations Protect Human Health.” Advances in Nutrition 10(1): 80-88.

Savary, S., L. Willocquet, S. J. Pethybridge, P. Esker, N. McRoberts and A. Nelson (2019). “The global burden of pathogens and pests on major food crops.” Nature Ecology & Evolution 3(3): 430.

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Thoughts on “Intensification for redesigned and sustainable agricultural systems.”

The need for farmers, scientists, regulators, and consumers to balance farming and food production systems with environmental conservation is only growing greater.  In many cases, this discussion gets framed by polarized views, with one side claiming that a return to low-tech solutions and an increase in agrarianism is best, while another responds with calls for technocratic solutions. Charles Mann highlighted this duality in his book The Wizard and the Prophet (Knopf, 2018, summarized briefly in the March 2018 issue of the Atlantic). While calls for Small Scale Organic vs Conventional Industrial Agriculture make for simplified debates, in reality, farms embrace multiple practices that could fit into both systems, often on the same farm or even in the same field. Like the realization that the U.S. is not divided into red and blue states but rather heterogeneous purple communities, agriculture is actually a pretty diverse field with a range of systems used. Much research on the matter concludes that that’s a good thing.

A recent review paper by Jules Pretty in Science [1] highlights the benefits of adopting progressive farming practices regardless of the ‘system’ that they may be ascribed to. The author posits that Sustainable Intensification (SI) may be a preferred system of farming that uses best practices based on their ability to “[maintain or increase production] while progressing toward substantial enhancement of environmental outcomes.” By selecting practices based on outcome rather than on input origin, the restrictive ideologies of competing systems may be cast aside and solutions chosen based on progress toward sustainability goals.

SI practices highlighted in the paper include efficiency, substitution, and redesign transitions in agricultural systems. Examples of those practices include, respectively: precision farming for improved fertilizer use efficiency; selection of disease-resistant plants that obviate the need for chemical inputs; and intentional design to harness biological systems, e.g. conserving natural predators of pests or soil improvement through crop rotations that benefit agricultural systems. I suggest that many farms are already practicing SI agriculture, even if they are considered ‘Conventional’, ‘Organic’, or whatever other label one wishes to use. However, my viewpoint if often blinded somewhat by my work in apple and grape systems in the northeast U.S., in which Integrated Pest Management (IPM), a key SI practice highlighted in the paper, is a mature field and is practiced to some degree on most, if not all farms that I work with [2-4]. Under IPM, crops and pests are managed using biological, cultural, and chemical contrails as dictated by a thorough understanding of crop condition, pest and predator populations, disease cycles, weather data, and economic thresholds for pest damage tolerance

However, IPM and Precision Agriculture are not as widely adopted in many regions and on many crops as on perennial fruit in Vermont. As Pretty highlights in his paper, great gains can be made in reducing environmental impact while increasing crop productivity by employing SI practices on farms. Figure 2 of the paper presents a pretty stunning picture of the value of adopting IPM specifically on farms in Africa and Asia, where farms that adopted SI practices increased mean yields by 41% while decreasing pesticide use by 31%. The application of knowledge- (rather than chemical-) intensive pest management and crop fertility systems are low-hanging fruit to improve agricultural sustainability, if only the application of information can be applied to management before resorting to agrochemical application. Knowledge of the farm system always makes for better application of farm inputs than shooting in the dark.

This same conclusion was reached in another recent paper in Nature [5] in which data from over 900 farms in France was analyzed to assess trends in crop production and pesticide use. Overall, it was concluded that French farms could reduce pesticide applications by about 40% on most farms without affecting production nor profitability. That French farms are among the highest per-hectare users of pesticides in the European Union, due in no small part to the importance of disease-prone winegrapes in the country, indicates that there is room for improvement through use of IPM.

Recent public pressure to reduce pesticide use, and, by proxy, system sustainability, on farms in France and elsewhere has often called for increasing, broad-stroke restrictions on certain pesticide products and uses. However, crop protection is a critical component of SI and Conservation Agriculture programs. The elimination of pesticide and other agrochemical inputs as a response to their improper overuse fails to credit their impact on increased crop yield and reduced yield stability [6, 7]. Call for reductions in food waste, as opposed to more efficient means of production, will ring hollow if loss of crop protection materials shifts the 44% of waste from agriculture and postharvest operations presently seen in North America to upwards of 70% of waste from those functions as is seen in South/Southeast Asia Saharan Africa and which have less access to modern crop protection systems.

As we see increased scholarship that shows how best SI practices like IPM can achieve improved environmental sustainability without negatively impacting farm profitability or crop production, I hope to continue to change the conversation from a competition between polarized tribes to a discussion of the best ways to nudge farming systems regardless of ideology. Pretty’s paper is a clear indicator of the potential for combining modern crop protection with low-tech crop and pest monitoring practices to forge a better agriculture.


  1. Pretty, J., Intensification for redesigned and sustainable agricultural systems. Science, 2018. 362(6417).
  2. Moran, R., G. Koehler, D. Cooley, A. Tuttle, J. Clements, C. Smith, G. Hamilton, W. MacHardy, L. Berkett, T. Bradshaw, H.H. Faubert, and M. Concklin, The New England Apple Scab-Control Practices Survey. Fruit Notes, 2016. 81(1): p. 1-6.
  3. Bradshaw, T. and L. Berkett. An Initial IPM Strategy for New Cold Climate Winegrape Growers. ASHS HortIM 2017; Available from:
  4. Bradshaw, T. and A. Hazelrigg. Status of IPM practice adoption in Vermont apple orchards in 2017. 2018; Available from:
  5. Lechenet, M., F. Dessaint, G. Py, D. Makowski, and N. Munier-Jolain, Reducing pesticide use while preserving crop productivity and profitability on arable farms. Nature Plants, 2017. 3: p. 17008.
  6. Oerke, E.-C., Crop losses to pests. The Journal of Agricultural Science, 2006. 144(01): p. 31-43.
  7. Popp, J., K. Pető, and J. Nagy, Pesticide productivity and food security. A review. Agronomy for sustainable development, 2013. 33(1): p. 243-255.


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Bob Parsons’ Celebration of Life on April 6, 2018

Sharing this information from my colleague Jane Kolodinski

To:       UVM Community

From:   Jane Kolodinsky, Professor & Chair

Date:    April 3, 2018

Please join us all of us in the Department of Community Development and Applied Economics, and Grace Matiru (Bob’s wife) and Jesse Parsons (Bob’s son) and family on Friday, April 6, 3:30-5:30pm in the Livak Ballroom of the UVM Davis Center for a Celebration of Life for Dr. Robert “Bob” Parsons.

Bob, who passed away on February 16, 2018, was known to many, not only in the University community but throughout the agricultural community in the states of Vermont and Pennsylvania, nationally, and internationally.  As a Professor, he worked with untold numbers of students in so many different capacities.  As an Extension Professor, Bob conducted outreach into the agricultural community visiting farms and farmers, conducting workshops and so much more.  He had unforgettable impacts on the lives he touched, and we know that many will want to attend this celebration to recognize his work and influence on our lives.  Please share this invitation with others who may also want to celebrate Bob.

The Celebration will be an informal reception to remember Bob’s contributions to the farmers, his students, his colleagues, and his family and friends.  It will be held on Friday April 6, 2018 from 3:30 – 5:30pm in the Livak Ballroom, Davis Center, 590 Main Street, University of Vermont in Burlington.  For parking on campus, please see the website at:

To support the work Bob was so passionate about, Memorial Gifts may be made out to the UVM Foundation, with “Bob Parsons Memorial Fund” written on the memo line. The address for the UVM Foundation is 411 Main Street, Burlington VT 05401.


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A tribute to Bob Parsons

Bob Parsons (right) and his wife Grace Matiru in action.

The agriculture, academic, and extension world lost a true friend with a sharp, grounded mind and a sense of humor only developed in farm fields, barns, and milk house driveways when Dr. Bob Parsons passed away Friday after a two-plus year battle with cancer. Bob’s impact on Vermont agriculture looms large, as he has been key in studying dairy and other farm sector economics; in overseeing the UVM Risk Management Agency; in directing the Vermont Farm Succession Program; and in being a sought-out resource for detailing agricultural economics at all levels and relating them to stakeholders. Despite being quite sick (and sicker than he’d led on to those of us who work with him), recently he was commenting on Vermont Public Radio on the current state of milk prices and helping one of our undergrad students do his taxes. The man was dedicated right to the end.

I first met Bob when he was a co-Investigator on the organic apple feasibility project which would eventually yield me both of my graduate degrees and a substantial stash of early-career research papers and experience. He served on both of my graduate committees, and anyone who knew him will appreciate it when I say that in our sessions I learned more about his grandfather’s tractors than I did about the topic at hand. But Bob didn’t just rattle on (well, he did, kind of)- he brought the conversation back to the realities of farming in modern conditions, considering the macro-, micro-, and family-scale economic conditions that farmers face. He just got it, from a farmer’s point of view, which is rare in the halls of academia.

Last Fall, Bob asked me to co-teach his Agricultural Policy and Ethics course for this current Spring 2018 semester. I knew this was a big step for him, as he hadn’t taken a day off since his diagnosis, since treatment options are quite available what with UVM Medical Center being a short walk from our offices. We didn’t say it explicitly, but I knew what was going on. “Bob, I can’t just sit in front of the class and rattle on about dairy policy off the top of my head like you can”, I told him. Bob said, and I clearly remember his words, “that doesn’t matter Terry, I know you can figure it out. These students need to hear from us, and I know that you can carry this on.” I am teaching that class this semester and think of Bob every day, and the task he handed me to present to these students the conditions farmers face to make a go of it in the modern local, national, and international economies. I can only hope that those students, when talking amongst themselves, refer to me in any of the same air as they did Bob when they would highlight his point of view as a needed balancing point to the standard fare from a progressive northeastern Land Grant University.

Bob and I are among the few,  real-live farm kids who teach in the UVM College of Agriculture and Life Science. My views have been shaped by both my upbringing on a small dairy farm and my many years in academic life, and tempered by a connection I have maintained with the farming community through the Vermont apple industry in particular. I often find myself bridging divides between old Vermont / new Vermont; organic / conventional; and applied / theoretical. People like Bob and I are few and far between in this strange world, and this world needs us.

I remember the first time I traveled with Bob to an academic symposium in Leavenworth, WA, a strange mountain town with a Bavarian fixation just upslope from Wenatchee, the self-proclaimed Apple Capital of the World. We were presenting some papers from that organic apple project, and I was lead or co-author on every one of them. This was among my first academic conferences, and certainly my first as author of multiple papers, including those from my Masters’ research. Frankly, I didn’t think that our economics paper was up-to-snuff, but I can still see Bob as he stepped up to the podium and started going through the slides. The graphs, despite having no statistical analyses, were quite clear- we were losing money in our simulations of organic orchard production, and Bob said to the crowd, “well, it doesn’t take a damned Ph.D. to tell that this isn’t working.” I still use that line when appropriate, as it so often is the case.

We did publish that research, and Bob was right. It’s important as an agricultural academic to stay grounded while staying current in the latest research in your field. As I consider my career and its place in Vermont agriculture, I look to mentors I’ve had like Bob Parsons who ‘get it’ for continued inspiration.

Thanks Bob, for all you’ve offered to me and the greater agricultural community in the years I’ve known you. You’ll continue to be an inspiration to me, and I promise to carry on in your spirit as I not only work with farmers, but also as I teach the next generation of farmers and food systems practitioners from the viewpoint of someone who has shoveled more shit than most will see in a lifetime, and who respects the advances we have today that make that job more rare than when we were kids.


Feb 21 update: Thanks for all the good words and responses on this piece. Since its first few hundred reads, I’ve tidied it up with a few wordsmithing edits and a narrowed focus on just Bob. -TB

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Food fears: more activist science and scientifically illiterate reporting

Much has recently been written about the poor state of scientific literacy in the U.S, and the media’s role in that downward slide.  At the same time, ‘industrial’ or ‘conventional’ agriculture, and the real, live farmers that contribute to it, continues to be damned by activists, non-governmental organizations, and enlightened people on social media. Similarly, academic objectivism has been hijacked by academic activism to provide an air of credibility to those who wish to portray the present farm and food system as in shambles. A recent journal article is making the rounds that exemplifies these concepts, and highlights many of the problems with both public and academic activism as it relates to and affects farmers and consumers.

The article posted in the Journal of the American Medical Association (JAMA), “Association Between Pesticide Residue Intake From Consumption of Fruits and Vegetables and Pregnancy Outcomes Among Women Undergoing Infertility Treatment With Assisted Reproductive Technology” (Chiu, Williams, Gillman, & et al., 2017) has been shared in social media and discussed in popular scientific venues quite a bit since its publication in late October 2017. (I won’t mention the shares it’s had among activist and issue-oriented websites like,,,, etc…their response to this confirmation bias is to be expected).

  • Science Daily reports, “Eating more fruits and vegetables with high-pesticide residue was associated with a lower probability of pregnancy and live birth following infertility treatment for women using assisted reproductive technologies.”
  • Huffington Post offers the headline, “Trying to get pregnant? Science suggests: eat organic and regulate the pesticide industry.” (Article written by Stacy Malkan, Co-director of the activist group U.S. Right to Know)
  • Reuters? “Women who eat more fruits and vegetables with high levels of pesticide residue may be less likely to get pregnant than women whose diets don’t include a lot of this type of produce, a U.S. study suggests.”
  • Modern Farmer says, “High-Pesticide Fruits and Vegetables Correlated with Lower Fertility Rates, Says Study.”
  • WebMD leads their story with, “Couples who are trying to have children should probably be picky about their produce, a new study suggests…”
  • Hell, even Nature got in on the story, “…Reproductive endocrinology: Exposure to pesticide residues linked to adverse pregnancy outcomes…”

The headlines and statements pulled from these articles all make it sound like we have a crisis on our hands, that our food supply has been shown by science to be unsafe, and pesticides are to blame. But let’s look at this paper a bit closer, with a skeptical and statistical focus.

This was an observational, case control  study. That means that the independent variable of concern, in this case, pesticide residue intake, is not under the control of the researcher. That doesn’t invalidate the study, but it immediately makes it a weak one. A group of 325 women who were receiving assisted reproduction treatments (in vitro fertilization, IVF) were polled about their diet for the past three months prior to assessment, as well as for other potential factors.  Fruits and vegetables (FVs) were tallied and compared to USDA pesticide residue database, using similar protocols as the Environmental Working Group’s ‘Dirty Dozen’ list. That annual report that highlights many conventionally-grown produce items as dangerously contaminated with pesticide residue has been heavily criticized as intransparent to its methodology; flawed in its calculation of risk; and sensationalized in its overhyping of meaningful results (Fenner-Crisp, Keen, Richardson, Richardson, & Rozman, 2010; Winter & Katz, 2011). In this present study, a cumulative risk calculation, “Pesticide Residue Burden Score” (PBRS), is tallied and assigned to each subject. While the PBRS is cited as having been previously used as a valid assessment technique in prior studies, all of those citations are from the same author’s lab group, which indicates that this categorical assigned value has little use in the authors’ field of study has not been replicated it in another study by another lab group.

Quibbling about statistical design aside, let me break it down here. The primary independent treatment variable, pesticide exposure (PBRS), is derived from: a) a retrospective questionnaire (how many of us could accurately say what we ate for the last three months?); b) a dataset of pesticide residue collected from a very small sampling of fruits and vegetables grown all over the world with no relation to how those growing conditions may affect actual pesticide load of the individual subjects nor of the variability of residues within samples; and c) were translated by the authors using arbitrary criteria into essentially a “big” and a “little” treatment. The number of jumps in the assumption train is boggling here, and we generally consider assumptions made based on assumptions of assumptions as a pretty poor way to assign treatment variables. The researchers could have done a simple, quantitative test here to confirm their assignment of exposure risk: measured pesticide metabolites in urine. That one step would have made for a stronger study, assuming it didn’t completely invalidate the PBRS treatments that were selected, which is entirely possible.

The dependent variables were more easily measured, discreet data points, things like number of embryos transferred, number implanted, clinical pregnancies, and live births.

Then, lots of ‘cofounders’, or other factors affecting the dependent variables  are discussed, including age, body mass index, race (but only ‘white’ race, yes or no), education, smoking history, organic food intake (self-reported, and also placed on an arbitrary categorical scale), and intake of thinks like alcohol, caffeine, and vitamins. So it seems that they screened out the other things that are well-known to impact pregnancy outcomes and are able to look only at the effects of PBRS, right? Sort of. Looking at Table 2, we see that in the ‘High residue’ group, the highest quartile (e.g. arbitrarily determined highest pesticide exposure) group had a statistically greater incidence of organic food intake than the lowest-residue (quartile 1) group. Yet, the paper explains in the discussion that eating organic food may decrease pesticide exposure, which is the complete opposite of the statistics presented in the paper. Similarly, we find statistically significant cofounders between populations all over the place, including various vitamin intake levels, infertility levels (HUGE problem …study should have been finished right there), and smoking rates.

The authors ran a bunch of correlation tests, which by design only point to associations between data points without any test for causation. Consider the popular correlation site Spurious Correlations that provides reported links between the number of films that Nicholas Cage appeared in and the number of people who drowned in a pool, based on actual data and associated correlations between variables. This highlights that correlation indeed does not mean causation; that the experimental variables were so vaguely defined and arbitrarily selected further highlights that there is little to no meaning to be drawn from the weak statistics used in the article. The authors mention adjustments made to “the model” to account for the cofounders, but the model isn’t made available in the actual article to evaluate. Sorry, that’s poor form for such a groundbreaking research paper, and indicates not only a lack of transparency but also a lack of scientific rigor with the entire premise of the article.

However, let’s assume that the model they developed to compare the arbitrary PBRS levels to pregnancy outcomes was valid. The outcome variables analyzed were a computed confidence interval (CI) for the various pregnancy outcomes (implanted egg, pregnancy, live birth). CIs are a commonly-used metric for guessing how correct your estimation is based on your sample mean and the variance among samples. Conducting a statistical test on computed Cis derived from assumptions of assumed assumptions (that’s a loss of four levels of freedom for the stats folks) makes this analysis a complete shot in the dark as far as having any statistical validity.

Given all of the problems with this study, it’s amazing that it was ever even published. The authors did give themselves an out, though. In the ‘Limitations’ section, they state:

“Our study has some limitations. First, exposure to pesticides was not directly assessed but was rather estimated from self-reported FV intake paired with pesticide residue surveillance data. Although we have adjusted for organic FV intake, data on whether individual FVs were consumed as organic or conventional were not collected, possibly leading to exposure misclassification…Second, our methodology does not allow linking specific pesticides to adverse reproductive effects. Further confirmation studies, preferably accounting for common chemical mixtures used in agriculture by biomarkers, are needed. Third, as in all observational studies, we cannot rule out the possibility that residual (e.g., significant differences in organic FV consumption across quartiles of high–pesticide residue FV intake) or unmeasured confounding may still be explaining some of our observed associations…”

How about this explanation: a group of scientists began their study on pregnancy outcomes with a highly risky population, as far as their dependent variables were concerned (women undergoing fertility treatment); made up arbitrary High and Low risk groups based on assumed data with no verification of  actual exposure; ‘accounted’ for cofounding variables that were significantly different across the treatment groups left the model out of the paper (“just trust us”), and overstated conclusions based on widely varying Confidence Intervals (calculated guesses for actual ranges among populations) of dependent outcomes.

This is, at best, a ‘hypothesis study”- something that sets further research down a path of study to determine what might be going on in a set of data that shows a certain trend. More realistically, it’s an activist-science fishing mission fed to a receptive media, and they have gobbled it up and spit it out. The saddest part of the story is that reputable media outlets with stretched staff and few reporters with scientific background and time to apply it are just parroting the press releases accompanying the paper.

And we, again, see the public discourse dumbed down, and we see the finger pointed at conventional farmers, with organic farmers offered an undeserved (going strictly on the evidence presented) halo. No one is saying that there shouldn’t be careful scrutiny applied to pesticides, or to any facet of agriculture that entails risk to both farmers and consumers. But this study, the conclusions it presents based on fairly weak evidence, and the media promotion around it aren’t adding much of substance to the conversation.

Chiu, Y., Williams, P. L., Gillman, M. W., & et al. (2017). Association between pesticide residue intake from consumption of fruits and vegetables and pregnancy outcomes among women undergoing infertility treatment with assisted reproductive technology. JAMA Internal Medicine. doi:10.1001/jamainternmed.2017.5038

Fenner-Crisp, P., Keen, C., Richardson, J., Richardson, R., & Rozman, K. (2010). A Review of the Science on the Potential Health Effects of Pesticide Residues on Food and Related Statements Made by Interest Groups.   Retrieved from

Winter, C. K., & Katz, J. M. (2011). Dietary exposure to pesticide residues from commodities alleged to contain the highest contamination levels. Journal of toxicology, 2011.


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My guiding principles for teaching farming and food systems

I have the best job in the (my) world. I was raised in the 80s and early 90s on a seventh-generation Vermont dairy farm in Orange County, where the cows have two legs shorter on one side than the other so that they can navigate the side hills that preclude large-scale ‘crop and chop’ farming that is practiced in other parts of the state and country. This was a small farm that operated during a time of great change in the industry, when greater economic conditions forced farms to “grow big or get out”, and alternative markets like organic and value-added were just beginning to be explored by the earliest adopters. Our scale and type of farming was an economic challenge, putting it mildly in some years, and I was never encouraged to come back and take over the farm because it was considered an economic dead-end to do so. (The farm is still there, yet the cows are gone- my parents make hay and rent the land out to several other producers who make maple and raise beef.) I went to college a first-generation University student initially with an expectation that I would get a degree in engineering to land a lucrative career in some city far off, but that didn’t last long.  At the University of Vermont I was initially a student in the Environmental Studies program and was exposed to a more critical lens that questioned farming and other practices, and I even went so far as to label my father an ‘environmental terrorist’ because he used herbicide in our cornfield. That was an awkward Thanksgiving…

While this new-to-me focus on environmental problems opened my eyes a bit, I was fast disillusioned by what I thought was lots of hollering and little concrete action to make change within the system. I transferred to the Plant and Soil Science (PSS) major in fall 1994. I still didn’t plan to be a dairy farmer, but I found my place. In PSS, I worked for the UVM Apple Team as a research assistant and was exposed to the Vermont apple industry, which includes multiple scales of production from small pick-your-own orchards to 250-acre farms where every apple is shipped out on a tractor trailer to impersonal wholesale markets.  My boss and eventual mentor, Dr. Lorraine Berkett, headed up the UVM Integrated Pest Management program, and through our work, we were having substantial effect on moving the conversation on farm sustainability forward. I left for a few years after graduation and worked in the commercial orchard world, including a 50-acre retail orchard in Massachusetts with over 100,000 customer visits annually, and as manager of a smaller, 15-acre orchard in Chittenden County. I was called back to the Apple Program in 1999 and have been there ever since, and have worked on numerous projects including evaluation of organic apple systems, winegrape management and cultivar evaluations, IPM implementation, and cider apple production systems, to name a few broad categories. In 2005, I was appointed assistant director of the UVM Horticulture Research and Education Center (Hort Farm). I’ve attained two more degrees in the PSS department, receiving my Ph.D. in 2015. The year prior to that, upon Lorraine’s retirement, I was appointed to the PSS faculty and have served as director of the UVM Fruit Program and continue to direct the hort farm and Catamount Educational Farm. In the past few years, I have also been increasingly teaching students in small-scale vegetable production and overall farm management.

In preparation for teaching a new (to me) course next spring, PSS 208 Small Farm Planning, I’m going through an intentional process to outline some of my principles which guide my teaching, outreach, and service activities. I’ll list them here, and will likely update this post as a sort if index as I flesh them out and, likely, add more as time goes by. In future posts, I’ll flesh out each piece, and those thoughts will likely inform new principles and re-thinking of ones I’ve already written on. So here begins my likely evolving list of Principles Supporting Instruction, Research, and Outreach on Specialty Crops Production in Vermont:

  1. We’ve all got to eat.
  2. Food production needs to happen at all scales.
  3. Farming isn’t natural.
  4. ‘Natural’ factors greatly influence farm systems and can contribute to both crop failures and successes. Our job is to foster the latter.
  5. Farmers are managers of complex biological, ecological, economic, and social systems.
  6. Farm and food system sustainability have benefited tremendously from modern scientific advances.
  7. With few exceptions, farmers are good people who are as interested in stewarding the land as those who criticize them.
  8. There are multiple sources and levels of knowledge that best inform the discussion around farming practices and food systems.
  9. The food supply in the developed world is the safest it has been in our history.
  10. The public wants safe, affordable food that is produced in an environmentally and socially sustainable manner, and that’s a good thing.
  11. Vermont is a unique place to live and farm. We need to celebrate that, but we also need to understand where our scale and types of production fit the food and farming systems in our greater region, nationally, and internationally.

I plan to flesh these out as time allows (good luck with that, TB). I look forward to synthesizing my thoughts and to a healthy discussion as these pages develop. Until then, don’t forget to eat your fruits and veggies.

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Food Evolution, criticism, and retrenchment: Missed opportunities for discussion


By Terence Bradshaw, Ph.D.

There’s a new documentary film out now, “Food Evolution”, that is reported to be a potential game-changer on the public perception and acceptance of genetically engineered (GE, or oversimplified as GMOs) crops. I haven’t seen the film- it was just released and doesn’t have a screening near me, and a one-night only one at a non-traditional theatre venue at that, until next Thursday. It has been shown at quite a few pre-screening events, so I’ll allow some license and assume that the 45 university faculty and other academics who recently signed a letter calling the film “propaganda” (whom I’ll call, “The 45”, for lack of a better term) have all seen it, although I believe that would have been difficult given their geographic distribution across and around the country. So this is not a critique of the film, it’s a critique of the knee-jerk criticism around it and a plea for a more informed conversation.

Let me start by saying that I think documentaries are a terrible way to convey objective information on just about any topic. Every piece of media has a bias, from dry research papers to lectures to films and videos. But documentaries, via their mixed visual, audio, storytelling, editing, and one-way dialog methods are particularly egregious. There is a whole genre of “Food and Farm Films” that has emerged in the current millennium, and many of the most popular ones, e.g., Food, Inc., The Future of Food, GMO OMG, Genetic Roulette, etc., are indeed extremely one-sided and in some cases blatant propaganda against modern agricultural systems, especially the use of biotechnology in agriculture.  Much of the debate around GM crop technology is indeed fueled by well-financed, private companies and activist groups that have funded biased research and promoted media  that stretch the lines of clear and logical reporting. Food Evolution is the first, or at least to my knowledge the most high-profile, documentary that reports from the pro-science side of the debate, which is so often misrepresented in the public media around GE crops.

As I said, I haven’t seen the film, but I have been following the discussion around it since it was being made. I also read both the literature and the popular and semi-scientific press around GM and other modern agriculture practices, and their application to food system sustainability. As an academic myself, I feel it is critically important to discuss an argument on its own merits, and to only discredit an argument based on characteristics of its presenter when that person has continually and egregiously shown a disregard of facts, science, logic, and respect.

So, in the response to the film that started this post, I see numerous ad-hominem attacks, as well as several statements that simply state that the film does not agree with the authors’ beliefs and therefore should be rejected as propaganda. First is the statement that the film “manufactures scientific consensus [on the safety of GE crops] where no such agreement exists”, and cites an editorial letter signed by fifteen anti-GM scientists and activists. I’m no expert on what makes a consensus, but the definition I use is the facts and conclusions around a particular issue on which those who have fully investigated the subject reach agreement and move on to the next matter for discussion. Of course there is always more research to be done on matters, but the overwhelming majority of scientific societies and regulatory bodies and scientists with understanding of the biological nature of GM crops  have agreed that the use of biotechnology in agriculture is safe. That does not mean debate ends there- there is always need for discussion on the best uses of the technology, its deployment in specific crop/pest/production systems, effects on supply chains and economics, and certainly on the regulatory process surrounding them. But to say that there is a legitimate question of the safety of the technology as a whole is untrue.

The authors of the critique then accuse the filmmakers of editorial bias in how they included GMO opponents in the film. Again I have not seen it, but there are a few points to make here. First, the fact that the filmmakers included substantial input and screen time from GM opponents suggests that they were open to dialog. Second, of course the sound bites were edited; that’s what a filmmaker needs to do to fit their narrative into a ninety-minute story line. Now a few of those included in the film are crying foul because their truthful statements are being used in a film supporting modern agriculture, which goes against their narrative and that of the movement in which they align. Dr. Marion Nestle is one of the most critical, and has openly critiqued her portrayal in the film (and Michael Pollan has followed up with a less well-developed, “yeah, me too” statement).  However, I have not seen anyone point out where the statements used were edited as to be untruthful. I would be interested in seeing a director’s cut with the rest of the interviews, but let’s face it- this film was designed (biased, as we all are) to tell its story. If they wanted Dr. Nestle to answer the question of whether or not GM crops are inherently safe to consume, then it’s their right to show that, as long as they didn’t splice the piece together to make it up. Dr. Nestle has her own substantial platform to provide the “yes, but…” qualifications to her statement.

As for inviting all sides of the debate to the table, a recent, comprehensive review of GM crop safety, applications, problems, and promises that did just that was undertaken by the National Academies of Sciences, Engineering, and Medicine (NASEM). The study was as comprehensive as any that has been conducted before or since, and included substantial input from published studies, public comments (over 700 reviewed), statements in public meetings and webinars, and two rounds of blind peer-review which included signers of the letter that started this post. The resulting, 606 page report is quite comprehensive, and, overall, paints GM crops in a positive light but also offers nuanced analysis of the safety, environmental, and economic impacts of the technology as it is presently and may potentially be used. Naturally, after the report was released, critics cried foul that the authors and reviewers were tied to corporate interests, and NASEM has pretty clearly refuted those accusation of bias. Look, when assembling a panel of professionals with diverse and extensive experience on a certain issue, many will have worked in one way or another in that field- that’s what makes them experts. That does not immediately assume nefarious wrongdoing on their part when critically examining a topic they know well.

Early in the process, a group of academics, many of whom are among The 45, denounced the makeup of the NASEM panel as essentially too reductive in their expertise, and not sufficiently rounded out by social scientists, agroecologists, farmers, women, or international experts. However, biotechnology supporters derided the report as not positive enough toward green-lighting GM crops. If both extremes on an issue highlight similar but opposing (and thus balancing) viewpoints on a subject, I’m inclined to believe that the presentation is balanced. The point in discussing that report here, is that a comprehensive, public, balanced forum has been provided and results written that did indeed include diverse viewpoints, and still reaches the conclusion as this film does that GM crops are safe and may be a useful tool to improve the sustainability and safety of food production.

Continuing with the original letter, more ad-hominem attacks are presented. The project funder, Institute for Food Technologists, is “an advocacy organization which has long endorsed the biotech industry,” despite it’s 70-year history as an academic and industry organization in support of scientific advancement in food production. “Mark Lynas works with the Cornell Alliance for Science, formed in 2014 with a US$5.6 million grant from the Bill & Melinda Gates Foundation to “depolarize” the debate over GM foods” (So what? Are they spreading untruths?). Animal scientist Dr. Alison Van Eenennaam “has worked in the past for Monsanto (so what if she did, if her science is accurate and truthful?). The notion that a person must be entirely discredited, despite being a leader in their field, because of past employment or funding from a company that you dislike or distrust, is not a logical refutation of their work.

Full disclosure:  I once received match funding for a research trial on organic soil disease management from a company that was later bought by a division of Monsanto. I describe that here. If that makes me a biased pawn of agribusiness, so be it. More disclosure: my academic CV is publicly available here . It contains the word ‘organic’ over ninety times, I received both graduate degrees working in organic production systems, and I founded and direct an organic teaching farm. Does that make me a pawn of ‘Big Organic’? I’d say that both disclosures are common of the types of scientists who hold a balanced, farm and food-centered perspective on agriculture. And a review of scientific articles on GM crops comparing funding sources and conclusions also indicated that there was little concern of false science in the peer-reviewed literature based on study funding, but that professional conflicts of interest (e.g. a scientist working for a corporation) were correlated with results favorable to the corporation (Diels et al. 2011).

So, public, University scientists tend to publish diverse articles regardless of funding source, including corporate funding (likely because we get ‘graded’ partly on the number of papers we publish); while corporate scientists publish information that helps the corporation, which is, by definition, a profit-driven institution. That doesn’t surprise me one bit, nor does it a) discount the independence of good public scientists nor b) discredit well-designed science that is published with a profit motive. Then again, poor science that muddies the discussion and is backed by corporate funds is indefensible, including some science that is expressly and overtly funded by organic food companies to cast doubt on the safety of non-organic food, thus increasing demand for their products which is well-detailed in a Slate article from 2015.

The letter writers then highlight a series of reports, articles, and stories critical of GM crops, but typically heavy on bias in reporting. Many of the reasons they oppose biotech crops (since everyone without a tinfoil hat seems to agree that they are not unsafe), including consolidation of agribusiness, seed patents, monocultures, pest and weed resistance, and declining farmer livelihoods are real problems, but the root cause is not biotech crops. Our agricultural systems are diverse and complicated, and each of those issues predates the relatively recent introduction of GM crops. While agroecologists and alternative food system supporters advocate for a fundamental reorganization of farming and society, the fact remains that incremental improvements within the massive food system do indeed generate substantial environmental, economic, and social benefits which were detailed in a 2014 meta-analysis (Klümper and Qaim 2014)  that concluded, “on average, GM technology adoption has reduced chemical pesticide use by 37%, increased crop yields by 22%, and increased farmer profits by 68%. Yield gains and pesticide reductions are larger for insect-resistant crops than for herbicide-tolerant crops. Yield and profit gains are higher in developing countries than in developed countries…”

As I have said, agriculture and our food system are extremely complicated, and there are many good farmers, scientists, and advocates working hard to make it better. The film Food Evolution is one step toward supporting those people in an arena where public discourse has consistently and often questionably cast doubt on their methods and aspirations. The coordinated, continued fear mongering over not just GM crops, but modern agriculture in general, demonizes farmers and other public servants while setting back progress on some real, important agricultural issues. Unfortunately, the opportunity for farm and food system advocates to pull a chair around this film to discuss issues is being missed, and each side appears to be retreating to their respective corners. That’s sad, and does a disservice to the roughly 90% of consumers who are not deeply involved in food production issues but just want and deserve a safe, plentiful, and nutritious food supply. I’m not the only one to observe this, others have highlighted how this film won’t change the discussion among values-based groups that simply cannot be convinced that farmers and scientists who support and use modern agricultural practices are doing so to be both competitive in the marketplace and to provide food for a growing population. No one is out to get you, and farmers really are good people, even when they choose to support Monsanto because they like the crops they offer

I planned to rebut some of the few specific accusation in the letter about specific GM applications that really do change the narrative, as they are not tied to agrichemical giants and their pesticides, and expressly support smallholder farmers. But I’ll let you read more about Hawaiian papayas and Ugandan bananas separately. Instead, I’ll leave with a plea to get out of our corners, stop ad-hominem and kneejerk reactions, and discuss issues rather than dismiss our ‘opponents’. And that includes the pro-GM community that has been smugly rallying behind this film yet participating in their own shady criticism, like using the Freedom of Information Act to harass members of The 45 and others critical of GM crops (I’m looking at you, Stephan Neidenbach). Members of The 45 include past and present colleagues, classmates, and teachers of mine, and I’ll happily engage them on these issues and ask that they consider sources contrary to their viewpoints, including Food Evolution, in framing their discussions. I still think documentaries make lousy sources for objective information, but they do present opportunities for discussion, and I encourage people from all sides to participate constructively as this conversation unfolds.

Food Evolution will be screened for one night only on June 29 at Main Street Landing Performance House in Burlington, VT, and is presented by the Vermont International Film Festival.

Literature cited:

Diels, J., M. Cunha, C. Manaia, B. Sabugosa-Madeira, and M. Silva. 2011. Association of financial or professional conflict of interest to research outcomes on health risks or nutritional assessment studies of genetically modified products. Food Policy 36: 197-203.

Klümper, W., and M. Qaim. 2014. A meta-analysis of the impacts of genetically modified crops. PloS one 9: e111629.



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Just a quick debunking post: Glyphosate and ‘toxic wheat’

Here we go again. It’s not scary Monsanto Gasmask Man, but it does feature Crop Sprayer Bad Guy. And more of the same misinformation. My explanation is below- this isn’t meant to be a dissertation or groundbreaking, blow-up-the-internet post, just one I can point to when this toxic wheat talk pops up…

On old article from just made it to my feed, shared by some friends of mine. I’m a little sad inside when good people get duped by the alt health ‘fake news’ media, so I’ll refute the posts’ claims, one-by-one, to settle their minds a bit.

The first claim: “Standard wheat harvest protocol in the United States is to drench the wheat fields with Roundup several days before the combine harvesters work through the fields as withered, dead wheat plants are less taxing on the farm equipment and allows for an earlier, easier and bigger harvest.”

First, let’s consider “drench” here. That suggests to me to spray to the point of saturation. Actually, when fields are sprayed with glyphosate, you’re usually talking about 2-6 pints per acre. That amounts to about 1/3 of a drop per square foot. Hardly a drenching, and if you do the math on the amount applied versus the biomass produced, not even taking into account degradation, soil binding, and runoff, you’re talking about parts per billion. As for “standard protocol”, it is actually quite rare to use glyphosate as a dry down material for wheat. Like, fraction of a percent rare. Most glyphosate is used pre-planting, well before there is any crop to be contacted.

Next is the use of Dr. Stephanie Seneff as a reliable source of information on the issue. Dr. Seneff is a computer scientist with zero training on plant science, toxicology, or epidemiology. She has recently been making the rounds on a kick against glyphosate ad has published several papers showing how it and GMOs (but never explaining which or their interactions) are to blame for rises in autism, cancers, celiac, nutritional disorder, you name it. The problem is, her papers are published in pay-to-publish, non peer-reviewed bunk journals and have been widely criticized across the scientific community to the point where she has no, none, zero credibility in this field. She may be a good computer modeler, I won’t doubt that. But these papers generally involve her developing a theoretical model to show a certain outcome, then of course her model gives that outcome, and she explains it with a bunch of bad science and poor reasoning. Even others in the alt health realm consider her a quack. Let’s remember that all of the supposed harms in the article are based on this questionable junk source.

As for USDA data showing “99% of durum wheat, 97% of spring wheat, and 61% of winter wheat has been doused with Roundup as part of the harvesting process. This is an increase from 88% for durum wheat, 91% for spring wheat and 47% for winter wheat since 1998”? The source given doesn’t even go to USDA data, but rather to another alt-health site the healthyhomeeconomist, which does indeed show a graph of percent of planted wheat acres treated with herbicides, fungicides, and insecticides, but to does not link back to the data. Nor does it say anything about the wheat being treated with glyphosate preharvest; usually, wheat fields are treated preplant which allows for no-till planting which is substantially better at conserving soil moisture, nutrients, and carbon (Alvarez et al. 1995, Reicosky et al. 1997, West and Marland 2002, McLauchlan 2006). Not to mention that glyphosate has a long track history of being among the safest herbicides available (Giesy et al. 2000, Williams et al. 2000, Roos et al. 2005, Mink et al. 2011, Mink et al. 2012, Székács and Darvas 2012, Williams et al. 2012, Kier and Kirkland 2013).

So you have a quack computer scientist saying that glyphosate causes all sorts of subtle but increasing health problems, an activist/alternative blog promoting data that doesn’t actually say what they say it does, and all demonizing a material with a long track history and better safety profile than its alternatives. I’d say this original article doesn’t have a leg to stand on.

But don’t just trust me, Snopes had the same thing to say:

“The most important point to take away from this article, however, is that it presents a flawed premise and doesn’t actually demonstrate any connection between current methods of wheat production and medical maladies in humans who consume it because:

  • The article does not document any recent increase in or unusually high level of wheat sensitivity in humans.
  • Even if an increase in wheat sensitivity were documented, that wouldn’t necessarily mean the phenomenon was due to a change in the production of wheat; it could simply mean that we are getting better at recognizing and identifying wheat sensitivities that have existed for a long time but previously went undiagnosed.
  • A documented increase in wheat sensitivity could have any number of environmental causes apart from the use of glyphosate in wheat production, and no causal connection between the two has been proved here.”



Alvarez, R., R. A. Díaz, N. Barbero, O. J. Santanatoglia, and L. Blotta. 1995. Soil organic carbon, microbial biomass and CO2-C production from three tillage systems. Soil and Tillage Research 33: 17-28.

Giesy, J. P., S. Dobson, and K. R. Solomon. 2000. Ecotoxicological Risk Assessment for Roundup® Herbicide, pp. 35-120. In G. W. Ware (ed.), Reviews of Environmental Contamination and Toxicology: Continuation of Residue Reviews. Springer New York, New York, NY.

Kier, L. D., and D. J. Kirkland. 2013. Review of genotoxicity studies of glyphosate and glyphosate-based formulations. Critical reviews in toxicology 43: 283-315.

McLauchlan, K. 2006. The nature and longevity of agricultural impacts on soil carbon and nutrients: a review. Ecosystems 9: 1364-1382.

Mink, P. J., J. S. Mandel, J. I. Lundin, and B. K. Sceurman. 2011. Epidemiologic studies of glyphosate and non-cancer health outcomes: a review. Regulatory Toxicology and Pharmacology 61: 172-184.

Mink, P. J., J. S. Mandel, B. K. Sceurman, and J. I. Lundin. 2012. Epidemiologic studies of glyphosate and cancer: A review. Regulatory Toxicology and Pharmacology 63: 440-452.

Reicosky, D. C., W. A. Dugas, and H. A. Torbert. 1997. Tillage-induced soil carbon dioxide loss from different cropping systems. Soil and Tillage Research 41: 105-118.

Roos, A. J. D., B. Aaron, J. A. Rusiecki, J. A. Hoppin, M. Svec, M. Dosemeci, D. P. Sandler, and M. C. Alavanja. 2005. Cancer Incidence among Glyphosate-Exposed Pesticide Applicators in the Agricultural Health Study. Environmental Health Perspectives 113: 49-54.

Székács, A., and B. Darvas. 2012. Forty years with glyphosate, pp. 247-284. In M. N. A. E.-G. Hassaneen (ed.), Herbicides–properties, synthesis and control of weeds. . InTech Europe, Rijeka, Croatia.

West, T. O., and G. Marland. 2002. A synthesis of carbon sequestration, carbon emissions, and net carbon flux in agriculture: comparing tillage practices in the United States. Agriculture, Ecosystems & Environment 91: 217-232.

Williams, A. L., R. E. Watson, and J. M. DeSesso. 2012. Developmental and reproductive outcomes in humans and animals after glyphosate exposure: a critical analysis. Journal of Toxicology and Environmental Health, Part B 15: 39-96.

Williams, G. M., R. Kroes, and I. C. Munro. 2000. Safety Evaluation and Risk Assessment of the Herbicide Roundup and Its Active Ingredient, Glyphosate, for Humans. Regulatory Toxicology and Pharmacology 31: 117-165.


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Agvocates: It’s your turn to stop the mud slinging

I wrote a blog post recently that criticized the use of graphic, inaccurate imagery in opposing GMOs and pesticides, and explained why doing so is offensive to farmers. Of anything I have written professionally on social media, this has been the most shared and well-accepted by the ag community. But watch what you’re saying, agvocates, because I have a few words for you, too.

Lets’ start this by saying I deplore the use of fear-based imagery in marketing and education. That’s represented in the aforementioned post. But I have also recently called out ‘agvocate’ voices for using hyperbole or bad reasoning in their arguments. When we take sides first and ask questions later, we risk falling on sloppy arguments ourselves. Painting any issue as black or white is a dangerous proposition. Agriculture, in particular, is an extremely complex field, with multiple biological, physical, and social parameters that interact and demand a higher level of analysis than some more cut-and-dry topics. In my job, I have feet firmly planted in the organic and non-organic buckets, and I tend to operate in that middle ground between the two where sustainability truly lies. There is a lot to learn from working within the organic system- that’s why we teach our summer undergraduate and Farmer Training Program students within the restrictive confines of a certified organic farm so that they may develop better skills when their farms really rely on it.

And that’s central to my point. All farmers, and often more so organic farmers, are very good at assessing these multiple, interacting forces that drive their management decisions. So when I see the argument made that, “so what, organic uses pesticides too,” I cringe a little:

For example, this meme that is often tossed around as evidence that organic is as evil as non-organic does no one any service except to make agvocates feel better about themselves. But think about it. You’re saying that organic pesticides are untested, and are just as bad or worse than non-organic pesticides. Sorry, that’s bullshit on many levels.

First, any pesticide approved for organic that is sold commercially must undergo the exact same safety testing as non-organic pesticides. That means that they all are subjected to the same toxicity, carcinogenicity, reproductive, and ecological effects. Period. So stop saying that organic pesticides aren’t tested. More important is to highlight that our pesticide safety and registration system is robust, risk management-based, and works. It’s because of that system that we have removed or curtailed uses of some of the indeed more toxic materials like azinphos-methyl and rotenone.

Next, the notion that organics indiscriminately douse their crops in copper sulfate and rotenone is ludicrous. For one thing, organic growers do indeed have a USDA certification standard that they must meet, unlike non-organic growers, which requires a prevention plan that includes biological, physical, and cultural controls. In my IPM world we talk that talk and often practice it, but no one (unless we’re part of a third-party certification program, which is few of us) calls us on whether or not we designed the system to reduce pesticide needs or sought other methods first. In my experience, except for certain instances where aggressive organically-approved inputs are required to manage pests (e.g., apple scab, black rot on grapes in the Northeast), organic farms by and large eschew prophylactic use of pesticides.

Now on to those pesticides that are supposedly drenched on organic farms. In several cases, the meme is just plain wrong about what is used. Take methyl bromide, for example- there is absolutely no allowance for it in organic production. Yes, strawberry nurseries use it when starting plants that are sold to organic farms, but so do apple nurseries use pesticides to get trees established that are sold to organic growers, and dairy farms use non-organic (often GMO) feed to produce the shit used to make organic-certified compost. There is certainly an argument to be made that organic producers require non-organic farms and suppliers to survive, but to suggest that organic growers use methyl bromide is just disingenuous.

As for rotenone and nicotine, yup, they’re nasty. But nicotine is expressly disallowed in the organic regulations, so just stop with that. And rotenone? Isn’t available as anything but a piscicide (meaning no use on crops in the U.S., since 2005), and the NOSB petitioned for its removal from the list years ago. I’ve struggled with growing organic apples in the northeast as a researcher for twelve years and have had massive insect outbreaks and trust me, rotenone, nicotine, and homemade concoctions were never on the table.

In my line of work, I consider myself a professional skeptic- I demand that evidence be used to support new and contrary claims. That said, I am also willing to take in new evidence on a matter. That’s why I was a bit surprised when a fellow horticultural professor exclaimed in her Facebook group that a new paper that reported that phylloshpere bacteria contributed to nitrogen assimilation in the host plant was bunk until “some time and radiolabelled nutrient studies…move this from correlation to causation” when that’s exactly what the paper was about (Doty et al. 2016). I’ll cut her some slack, she admitted to posting before reading first thing in the morning without coffee. But the knee-jerk reaction that an alternative system may be responsible for at least a portion of the nitrogen cycle in plant environments is indicative of a bias against alternative systems that goes beyond skepticism. Look, I am the first person to question permaculture, moon planting, and similar alternative production practices, but if I am presented with solid, peer-reviewed evidence that runs contrary to the traditional mode of thinking, I listen.

At the same time, it is difficult to stomach the hyperbole in a headline like, “Organic Farming is Bad for the Environment,” posted from a leading science skepticism site. I understand fully the organic yield gap (Kravchenko et al. 2017), and the contradictions of the need for nitrogen from non-organic farms and soil carbon loss from tillage (McLauchlan 2006). But this articles takes quite a lot of liberty in its assumptions, ignores life cycle analysis of nitrogen synthesis, and does not address potential advances in organic, and more so, sustainable production systems moving forward with the tools we now have available. Are there issues with crop yield, food affordability, and (possibly) soil quality decline under organic systems? Maybe, but there are also issues with agricultural runoff, soil quality decline, pest resistance development, and food distribution (among other things) in the present non-organic system. There’s no high horse to ride when we take sides.

I prefer to think back to the 1990s vision of a Low Input Sustainable Agriculture model which includes the best tools from the organic and non-organic worlds to develop a farming and food production system that minimizes unintended impacts while feeding a growing population and rewarding farmers. This vision was highlighted in a recent review publication of European literature on organic farming (Tuomisto et al. 2012):

“This meta-analysis has showed that organic farming in Europe has generally lower environmental impacts per unit of area than conventional farming, but due to lower yields and the requirement to build the fertility of land, not always per product unit. The results also showed a wide variation between the impacts within both farming systems. There is not a single organic or conventional farming system, but a range of different systems, and thus, the level of many environmental impacts depend more on farmers’ management choices than on the general farming systems. In our view, there will be no single best farming system for all circumstances. Rather it will be necessary to compose ‘optimal’ systems from a series of particular practices that relate to specific circumstances, constraints and objectives.”

This ideal system will only come when we stop demonizing one another and act together. I can’t speak for the Organic companies and activist groups behind much of the demonizing of non-organic food production (Schroeder 2014), they really are bastards. But as farmers, academics, and informed citizens we owe it to everyone to step up our game and rise above it.


Doty, S. L., A. W. Sher, N. D. Fleck, M. Khorasani, R. E. Bumgarner, Z. Khan, A. W. Ko, S.-H. Kim, and T. H. DeLuca. 2016. Variable nitrogen fixation in wild Populus. PloS one 11: e0155979.

Kravchenko, A. N., S. S. Snapp, and G. P. Robertson. 2017. Field-scale experiments reveal persistent yield gaps in low-input and organic cropping systems. Proceedings of the National Academy of Sciences.

McLauchlan, K. 2006. The nature and longevity of agricultural impacts on soil carbon and nutrients: a review. Ecosystems 9: 1364-1382.

Schroeder, J. 2014. Organic marketing report, pp. 16. In B. Chassy, D. Tribe, G. Brookes and D. Kershen [eds.], Academics Review. Academics Review.

Tuomisto, H. L., I. Hodge, P. Riordan, and D. W. Macdonald. 2012. Does organic farming reduce environmental impacts?–A meta-analysis of European research. Journal of environmental management 112: 309-320.


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Monsanto Gas Mask Man: Activist imagery and its meaning to farmers

Edit: a few clarifying edits were made after initial publication. Also, a second, related essay was posted to call out hypocrisy and lazy thinking among the modern-agriculture advocates.

Recently I had a spat with a colleague over what I thought was her use of negative imagery toward non-organic farmers in a lecture. One thing that really got me going was the use of what I call “Monsanto Gas Mask Man” in a slide that discussed some of the dangers of pesticides.



We’ve talked since, I aired my concerns and she hers, and we are in a good place. I respect her. But those images are everywhere in the online and other discussions around modern agriculture. I’ve stewed a bit over my reaction to them, and have come up with a few points of discussion.

I’ll frame this first by mentioning my farming background. I was raised on a small, conventional Vermont dairy farm in the 1980s and 90s. We weren’t organic (no one was doing organic dairy then), but we were a largely pasture-based farm that struggled to compete in the modern commodity landscape. Dad did his best to ‘modernize’- we used synthetic fertilizers; employed improved herd genetics to get our production per cow up; grew corn occasionally using herbicides; and even docked tails in the later years to reduce somatic cells counts in our milk. We were a 45-50 head, tie stall dairy that struggled in the greater economy, yet we held on when many of our neighbors went out of business, and my folks sold the cows at the turn of the millennium after Dad had been working a full-time job off the farm for about five years (Mom always did, or we wouldn’t have eaten) so that he could pay himself to farm.  I know the blood, sweat, and literal tears that farmers put into their work, to feed people. And while there are certainly impacts from many agricultural practices on the environment and rural economies, I have never known a farmer, even the few jerks I know in the business, who wants to hurt people.

Since leaving my home farm, I have worked in the industry as a fruit grower and more so as a researcher and instructor. The majority of my current work is with non-organic apple and grape growers, who use agrichemicals as a regular part of their work. The recent discussion over GMO and other farming production methods in the popular media has been largely and carefully directed by activists to paint ‘conventional’ agriculture in an extremely negative light. The rhetoric around non-organic agriculture has been directed using intentionally provocative terms and images, in order to sway public opinion based on fear and emotion rather than science and reason (Clancy and Clancy 2016, Kangmennaang et al. 2016).

The “Monsanto Gas Mask Man” plays into that imagery. Such an image suggests a soldier in a war- the gas masks evoke direct wartime imagery; and the hazmat suits, especially the super-thick nitrile gloves, suggest an outer space-like hostile environment. Faces are obscured, like Storm Troopers. Notice how the company logo is prominent in each well-staged picture. Such imagery places farmers, who are really only trying to make a living, often to sustain a multi-generational family farm in tough times and to produce food for all of us, as disposable pawns at the hands of a corporate general.

I have several problems with the use of such imagery, but I don’t knock my colleague for using it. She has not worked in a pesticide-intensive crop, and therefore does not readily have farm pictures available to use in a lecture. A google image search for ‘pesticide exposure’ brings up a whole host of scary images. However, there are a number of inaccuracies in the photos posted above.

For one, I have seen and worn much personal protective equipment (PPE) used to protect the applicator during spraying, and I have never seen a farmer use the single-canister gas mask-style respirator seen in the photos. I don’t doubt they exist and are labeled for use in applying pesticides, they aren’t commonly used on farms. But where are they commonly seen? In military, survivalist, and other wartime situations. There are some really creepy images out there, and they are often watermarked as stock images, e.g. carefully crafted images for use in developing marketing and other persuasive (activist) campaigns:


Most growers I know, when required to wear a respirator, choose a half-mask type, similar to ones used by painters:


Of course, the specific pesticide label legally dictates the amount of PPE to wear when mixing or applying in order to protect the handler from carefully measured and known hazards. I’ll cover the materials shown in the original images in a minute, but for now, lets’ consider glyphosate, highlighted in the imagery by its original brand name Roundup, and almost always identified by its original manufacturer, Monsanto:


Much has been written about the dangers of glyphosate and various papers and studies that claim to support its toxicity- we can discuss that later. However, considerable, long-term evaluation of the research ad safety data indicate that glyphosate is, for a pesticide, relatively safe (Williams et al. 2000, Roos et al. 2005, Mink et al. 2011, Mink et al. 2012, Székács and Darvas 2012, Williams et al. 2012, Kier and Kirkland 2013). Because of that, the PPE required for its application includes “long-sleeved shirt and long pants, shoes plus socks.” That’s it:

6. Worker applying glyphosate-based herbicide and wearing appropriate personal protective equipment. TB photo.

But in popular and activist press, a very different image is used:


And we’re back to the scary imagery…in an NPR article nonetheless!

As for the specific images referenced at the beginning, let’s consider the materials in the photos. I will never say that every pesticide is safe, in fact I teach pesticide safety as part of my job, I am also familiar with the safety and registration process the EPA uses to review and license pesticides. A typical pesticide requires around $10-20 million for registration, and much of that is used in required short- and long-term testing for acute and chronic toxicity, carcinogenicity, mutagenetic, and environmental effects. The results of that testing determine allowed use restrictions, including rates, timing, and other safety considerations; the requirements for those tests would take several hundreds of pages to print. My point is that pesticides are indeed inherently harmful, and there is a good safety program in-place to regulate their use, which includes the use of appropriate PPE, and use restrictions that limit rates, timing, and other application criteria. (Why even use them at all? To reduce the 25-80% of crop losses attributable to pests that would decimate our food supply (Oerke 2006)).

So, consider those original images. The first material highlighted, Lasso, is an herbicide containing the active ingredient alachlor which is indeed pretty nasty, as it is a pretty powerful carcinogen. How much alachlor is used in modern agriculture in the U.S.? Extremely little, because it has been replaced by the dramatically safer glyphosate, aided by herbicide-tolerance traits in genetically engineered field crops. So the demon GMOs have indeed helped to push out a pretty toxic material, which goes against the scary spray guy analogy. (Ironically, the little bit of alachlor still used is primarily in ‘Non-GMO Project’, corn and soybeans. That Non-GMO Project sure is doing good things, huh?).



How about that other material in the Greenpeace photo, “E605 Forte”? That’s an insecticide containing parathion, a highly toxic organophosphate (OP) material whose use was cancelled in the U.S. in 1991, and which is severely limited elsewhere in the world (although I imagine used in the developing world, unfortunately). The whole class of OPs has been reviewed since the adoption of the U.S. Food Quality Protection Act in 1995, and not only has their overall use gone down substantially since then, but the new materials that have been developed in their wake have significantly lower toxicity profiles (Jones et al. 2010).

At the risk of dragging things out, my aversion to this imagery is based on the lies behind it- that farmers are trying to hurt anyone, that our food system is unsafe and riddled with dangerous chemicals, and that organic farmers inherently are above such nastiness. Because here I am, spraying an approved pesticide on my organic apple crop, wearing the appropriate PPE for the job.

9. The author applying sulfur-based pesticides to an organic apple crop. TB photo.

Farming isn’t performed by beautiful elves flitting about their fields of green, nor is it done by ogres and trolls at the hands evil corporate overlords. It’s done by real people, who bust their butts to feed us (you). Demonizing them (us) via violent imagery and rhetoric is an insult to us all, as farmers, consumers, and citizens, and that’s why I speak out against it. With no disrespect to my dear friend who started me on this rant, I suggest we all step back and think about how we portray them, especially those of us who know better.



Clancy, K. A., and B. Clancy. 2016. Growing monstrous organisms: the construction of anti-GMO visual rhetoric through digital media. Critical Studies in Media Communication 33: 279-292.

Jones, V. P., S. A. Steffan, L. A. Hull, J. F. Brunner, and D. J. Biddinger. 2010. Effects of the loss of organophosphate pesticides in the US: opportunities and needs to improve IPM programs. Outlooks on Pest Management 21: 161-166.

Kangmennaang, J., L. Osei, F. A. Armah, and I. Luginaah. 2016. Genetically modified organisms and the age of (Un) reason? A critical examination of the rhetoric in the GMO public policy debates in Ghana. Futures 83: 37-49.

Kier, L. D., and D. J. Kirkland. 2013. Review of genotoxicity studies of glyphosate and glyphosate-based formulations. Critical reviews in toxicology 43: 283-315.

Mink, P. J., J. S. Mandel, J. I. Lundin, and B. K. Sceurman. 2011. Epidemiologic studies of glyphosate and non-cancer health outcomes: a review. Regulatory Toxicology and Pharmacology 61: 172-184.

Mink, P. J., J. S. Mandel, B. K. Sceurman, and J. I. Lundin. 2012. Epidemiologic studies of glyphosate and cancer: A review. Regulatory Toxicology and Pharmacology 63: 440-452.

Oerke, E.-C. 2006. Crop losses to pests. The Journal of Agricultural Science 144: 31-43.

Roos, A. J. D., B. Aaron, J. A. Rusiecki, J. A. Hoppin, M. Svec, M. Dosemeci, D. P. Sandler, and M. C. Alavanja. 2005. Cancer Incidence among Glyphosate-Exposed Pesticide Applicators in the Agricultural Health Study. Environmental Health Perspectives 113: 49-54.

Székács, A., and B. Darvas. 2012. Forty years with glyphosate, pp. 247-284. In M. N. A. E.-G. Hassaneen (ed.), Herbicides–properties, synthesis and control of weeds. . InTech Europe, Rijeka, Croatia.

Williams, A. L., R. E. Watson, and J. M. DeSesso. 2012. Developmental and reproductive outcomes in humans and animals after glyphosate exposure: a critical analysis. Journal of Toxicology and Environmental Health, Part B 15: 39-96.

Williams, G. M., R. Kroes, and I. C. Munro. 2000. Safety Evaluation and Risk Assessment of the Herbicide Roundup and Its Active Ingredient, Glyphosate, for Humans. Regulatory Toxicology and Pharmacology 31: 117-165.



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