Pesticides and food: It’s not a black and white issue

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FIRST ARTICLE: Has pesticide use decreased over the last 40 years?

Do organic farmers really use more pesticides than conventional farmers? Not even close.

This is part one of a four-part series attempting to separate fact from fiction regarding pesticide use on organic farms. In this installment, we look at the common claim that organic farms actually use more pesticides and more dangerous pesticides through the lens of a few simple observations and talking to actual organic farmers. In part two, we look at the factoids that have been taken out of context and twisted into a dishonest narrative. In part three, we look at the special cases of pest control in organic orchards and vineyards. Finally, in part four, we take a critical look at a widely circulated article purportedly busting myths about organic farming that managed to create a few myths.

As opinions about farming have become increasingly politicized and polarized, a really unfortunate trope has taken hold. In pushing back against the fear mongering about pesticide safety driven by organic marketers and the widespread consumer belief that organic farming means zero pesticides, some advocates for conventional agriculture have begun counter-mongering – claiming that, in fact, organic farms use MORE pesticides and the pesticides are MORE DANGEROUS than conventional pesticide use.

This all too common trope takes a few factoids and twists them in dishonest and unproductive ways.

Friendly advice about organic pesticides
There’s more wrong with this statement than the bad grammar and typos.

We don’t have clean data on how much pesticides are used on organic farms. The vast majority of pesticides approved for organic use are used on conventional farms, and while data is collected on total sales (and amounts applied per acre, number of treatments per year, etc.), it is not broken down by whether farms are certified organic or not. We are left trying to get at the truth of the matter in a number of different ways.

First, the idea that organic farmers are secretly getting away with using more pesticides than conventional farmers can be dispensed with in a general sense by way of a few simple observations, before taking a more granular look at the issue.

Herbicides

Weeds are by far the most common, widespread pests that farmers deal with and herbicides are by far the most widely used class of pesticides. There are no economically viable organic herbicides used at any type of scale.

Pesticide use in the U S

So, if you remove herbicides from the equation it’s hard to see how organic farms are going to end up using more pesticides then their conventional counterparts.

On farm biodiversity

Screen Shot at PM
On average, morphospecies richness of plant-feeding insects and parasitoids was significantly higher on the commercial organic than conventional tomato crop. (Letourneau and Bothwell – pdf)

Although it’s not a perfect proxy for pesticide use or the impacts of pesticide use, measures of impacts on biodiversity, and on-farm biodiversity in particular, are a decent indicator of the impacts of pesticide use. While conventional systems consistently do better in comparisons to organic systems in terms of the environmental impacts I consider the most critical – greenhouse gas emissions, eutrophication and acidification potential, land use, and regional biodiversity – local and on-farm biodiversity is an area where organic systems consistently and significantly come out ahead of their conventional counterparts. If you are using more and more toxic pesticides, you aren’t going to have more critters: birds and bugs and bees around your farm. A 2005 meta-analysis found organic farms generally have 30% higher species richness and 50% higher abundance of organisms than conventional farms. Other studies since then have found similar effects.

Likewise, a report assembled by the Swedish Food Agency found that, while conventional was better for the environment on many metrics or found little difference, eco-toxicity was the one measure where organic systems performed consistently across the production of various crops and livestock animals.

So those are two relatively straightforward observations that have led me to be very skeptical of claims that organic farms are secretly using more pesticides than their conventional counterparts.

Ask a farmer

Next, I tried something pretty simple. I just asked some organic farmers what kinds of pesticides they used and how often. I started on the Food and Farm Discussion Lab Facebook forum that I run. Here is a sampling of answers:

Carolyn Olsen from Cottonwood, Minnesota raises organic corn, soybeans, alfalfa, wheat, and depending on year oats, barley, or triticale on 1,100 acres, and custom finishes around 7000 pigs a year (not organically certified) for a neighbor:

“Sometimes we use a foliar feed to prevent fungal issues in our small grain, but not every acre. I’d say less than 200 acres of our 1,100 acres total are treated. No pesticides are used on the corn, soy, or alfalfa.”

Adam Ornawka, who farms 4,100 acres of conventional and 640 acres of organic hemp, lentils, wheat, and oats in Saskatoon, Saskatchewan:

“I don’t use any pesticides with the exception of diatomaceous earth to keep bugs out of stored grain.”

Michael Adsit, who grows organic apples, asparagus, raspberries, oats, rye, hay, and pumpkins in Plymouth, Michigan:

“We use mostly foliar sprays of nutrients to boost plant health and immunity. We will use Entrust (an insecticide produced by Dow AgroSciences produced through the fermentation of a naturally occurring soil bacterium, spinosad), only with a threshold insect infestation, on organic apples and raspberries, based on field traps to monitor. Rarely more than once a year. Also PyGanic (an organic pyrethrum insecticide — derived from chrysanthemum flowers produced by Valent), only on raspberries for spotted wing Drosophila. We will use mineral and tree nut crop oils in early spring, not as an insecticide but smothering cover.

The main organic strategy is to have really healthy trees that are disease and pest resistant. Secondly use traps, pheromone disruption and barriers to discourage insect pests. Third, at last resort use products like Bt, Entrust, pyganic, lime sulfur, oxidate, crop oils to suppress insect, fungus infestations. In the last two years we have only used Entrust in early spring for apple flea weevil and crop oils on the trunks to smother plum curculio. Fruit itself was never sprayed.”

Related article:  Chemical residues on foods and why dose matters

Julaine Treur, a dairy farmer in British Columbia, Canada:

“We grow corn for silage and earlage, and a grass, alfalfa, and clover mix for silage, hay, and pasture. 180 acres of grass and 40 acres of corn. Zero pesticides used in our 6 years farming organically.”

Haven’t used a pesticide of any sort on our crops. Never really seen a need to. I find it amusing how much time conventional farmers spend talking about all the spraying organic farmers do since I don’t even own a sprayer.

– Tim Zweber, Zweber Farms, Elko, Minnesota

Tim Zweber of Zweber Farms in Elko, Minnesota, a dairy farm growing hay, sudex, and small grains:

“Haven’t used a pesticide of any sort on our crops. Never really seen a need to. I find it amusing how much time conventional farmers spend talking about all the spraying organic farmers do since I don’t even own a sprayer.”

Joan Kissner-Lee, growing organic hay, corn, oats, and sometimes soybeans in McIntosh, Minnesota:

“We have been organic since 2006 and have never used any type of pesticides.”

Rob Wallbridge, former organic farm inspector and vegetable, berry, and grain producer, current organic agronomist and consultant in Ontario, Canada:

“Between 1998 and 2015 we grew a few acres of organic vegetables, strawberries, and raspberries. Bt spray on cabbage, broccoli, and cauliflower (2-3 times per year) was the only pesticide that I didn’t quickly find a way to manage without. I did experiment with diatomaceous earth against striped cucumber beetle in particularly hot and dry years. I also did a trial with neem oil against Colorado potato beetle on potatoes and eggplant one year too – not that impressive. And back before the turn of the century (before it was de-registered for all agricultural use), I seem to recall dusting a few dozen melon transplants with rotenone.”

Jasen Gibbons, currently farming about 1,250 irrigated, organic acres in the Pacific Northwest. Corn, potatoes, alfalfa, buckwheat, small grains and a plethora of cover crop/beneficial mixes (and maybe a weed or two at times):

“No pesticide use here…but it’s not for the faint of heart at times

I get a kick out of my kids and their enthusiasm for wild animals and bugs. I had their preschool teacher ask me once what a “beneficial” is? It’s amazing to walk the fields and see how much life there is.”


I followed up and asked a few friends who work as organic inspectors and consultants for both conventional and organic farms to look over the comments on the thread. I wanted to know if what people were saying squared with their experiences and all three told me that it did. This was an admittedly self-selected group of farmers – they are all members of Food and Farm Discussion Lab, which has a certain culture, and they all chose to speak publicly about their pesticide use. Nor is it representative of some important aspect of organic production, notably large scale fresh produce in California’s Central Valley and vineyard production. We’ll cover those in part three. But this informal poll does reveal that it’s not at all uncommon for organic farmers to use little to no pesticide.

While plenty of conventional farms use robust integrated pest management (IPM), beneficial insects, and the cultural practices of diverse rotations, mulches, cover crops, and a focus on soil and plant health to control pests, they also have access to more effective and affordable pesticides. Organic farmers are required to use cover crops, more diverse rotations, and have to submit annual IPM plans as part of their certification. Beyond the prohibition on synthetic pesticides, whether it’s the cost and lesser effectiveness or a commitment flowing from a specific set of values, my experience is that organic farmers, by and large, turn to pesticides only as a last resort to a greater degree than conventional farmers. That trade-off affects other sets of environmental impacts. That’s a topic too large to get into in any detail for the purposes of this series. Regardless of whether you think those trade-offs are worth it or not, it’s pretty clear to me that organic farmers use pesticides very sparingly.

The exception to that rule is in citrus, vineyard, and orchard production, where many of those cultural practices are not options – you can’t rotate an apple orchard every year to break up pest cycles – so using pesticides sparingly is not an option either. We’ll take a look at the cases of orchard and vineyard pest control in part three.

Where did this idea come from?

Like most popular misconceptions, the idea that organic farming uses more pesticides and more dangerous pesticides springs from a few scraps of truth and accurate factoids. There are types of organic farms where the pesticide use is more impactful than their conventional counterparts. There was a highly toxic organic pesticide that was phased out of use around twenty years ago and a lot of people haven’t gotten the memo. And like most popular misconceptions, there was one piece of egregious reporting that became the source of misinformation for far too many people.

But to walk through all the history and nuance on this issue is going to take a few more installments.

Marc Brazeau is the GLP’s senior contributing writer focusing on agricultural biotechnology.  He also is the editor of Food and Farm Discussion Lab. Follow him on Twitter @eatcookwrite

34 thoughts on “Do organic farmers really use more pesticides than conventional farmers? Not even close.”

  1. I remember the first time I heard about smothering insects with oil:

    “We found the mineral oil organic pesticide had the most impact on the environment because it works by smothering the aphids and therefore requires large amounts to be applied to the plants,” said Hallett.

    Compared to the synthetic pesticides, the mineral oil-based and fungal products were less effective, as they also killed ladybugs and flower bugs, which are important regulators of aphid population and growth.

    I thought: well, smothering is pretty broad-spectrum. I’d rather see more species-specific stuff–I’m with Rachel Carson on that.

    https://www.sciencedaily.com/releases/2010/06/100622175510.htm

    • Rachel Carson published Silent Spring in 1962. I grew up on a fruit and vegetable farm 1940’s -1965. We used the pesticides that were available to us at the time. It boiled down to control the pests or not have a crop. We used emulsifiable oil in the spring before the leaves came out. It was used to control oyster shell scale and other insect eggs. It could not be used after leaves came out, it would burn the tissue and plug the pores.

  2. Isn’t it possible that your “ask a farmer” strategy for measuring pesticide use by organic farmers suffers from the common problem of self-reporting bias? IOW organic farmers who use pesticides routinely and perhaps in significant amounts might not report to your survey, or under report if they do.

    It’s like the old truism when asking men to report about frequency of sexual intercourse and alcohol consumption: Divide the former answer by two, and multiply the latter by the same.

    • Absolutely. That’s why I also asked inspectors and consultants who get around if they comments squared with their overall experiences. And why I looked at the comparisons of on-farm biodiversity and eco-toxicity. And the group is self-selected by the kind of farmers who are active on that forum (forward thinking).

      There are certainly specific crops where the profile of organic pesticide use is closer to that of conventional – produce farming in the Central Valley for instance – and some where it’s is on average worse – orchards and vineyards in the US (part three) and banana production in Central America (part two).

      • I know you’re doing the best with the available data, but as a former scientist I’ve always harbored a suspicion of observational/empirical evidence. Easily subject to all sorts of biases.

        “A man [sees] what he wants to [see], and disregards the rest.”

        We had a project in developmental immunology where we could see what we knew to be “true” but we just lacked the tools to quantify the observations. So we didn’t publish. Ten years later, with better tools, it was reported (confirmed) by others (our competitors).

        • I disagree. I think you are missing a crucial distinction.

          A hypothesis usually can’t be demonstrated through simple observations, but it’s often possible to falsify a hypothesis with a simple observation.

          But I stated clearly that I don’t regard the observations regarding herbicides and on-farm biodiversity/eco-toxicity as proof, but of evidence that leads me to be highly skeptical of the overall trope that organic farmers are using more pesticides and more dangerous pesticides than conventional farmers.

          • Then we’ll have to respectfully disagree. The ability to falsify a hypothesis with anecdotal evidence depends largely on how the hypothesis is formulated.

            But are you seriously contending that glyphosate (for example) is as toxic as many of the pesticides permitted for use in organic-certified agriculture? Pesticides such as copper sulfate, nicotine and rotenone? If so, well then we are not even in the same universe.

          • Coming at it from a fresh perspective, having never before seen the trope you reference, I see two possibilities: (1) Organic agriculture uses more pesticides per acre per growing season than conventional agriculture, and (2) Organic agriculture does not . . . etc.

            You appear to be attempting to falsify #1. And for the reasons I’ve stated, I don’t find self-reported/under-reported use (even if supported by second-level observational/empirical data) to be very convincing. But that might be because, in addition to being a former scientist, I practiced law for three decades (and specialized in agricultural biotech for the first of those), so I tend to view evidence from a fairly stringent perspective.

            Keep in mind that I’m not saying you’re wrong, but rather that I’m just not (yet) convinced that you’re correct. In part this is because I’ve read reports (in GLP or various pro-GMO sites) from organic farmers who’ve switched back to conventional agriculture and are using far less pesticide (in frequency of application at least) as a result. But of course, those reports suffer the same criticisms I’ve already voiced.

            But I will look forward to reading the remainder of your series.

          • Yes. I see the claim as Total Average Pound per acre.

            So if you take herbicides out of the equation, you have to believe that organic farmers are using something in the range of 3 to 5 times more insecticide/fungicides/other pesticides to make up for that.

            The claim that organic uses more and more toxic pesticides also implies certain predictions. One would be that on-farm biodiversity should be lower than the counterfactual. The other would be that measures of on-farm eco-toxicity should be higher. Neither of those propositions are true.

            But all I said was:
            “So those are two relatively straightforward observations that have led
            me to be very skeptical of claims that organic farms are secretly using
            more pesticides than their conventional counterparts.”

            In no way did I imply that the matter was settled, only that between the herbicide issue and then the measurements of on-farm biodiversity, the MORE and MORE DANGEROUS trope seems pretty dubious.

            People have really reacted to a post that was intended as warm up exercise – let’s start by kicking the tires – in ways that have really surprised me. The level of hostile motivated skepticism and pedantry that this series have been met with has been pretty breathtaking to be honest.

  3. Interviewing organic farmers in areas with low pest pressures compared to say, Florida might skew the results. Smothering insects is using the oil as an insecticide.,

  4. Hi Marc, I applaud your endeavour and also applaud the publication of it here. I have no ideological qualms about organic or conventional farming, having colleagues in both areas.
    As pointed out in other comments, your method of using statements of organic farmers is deeply flawed, and should not be taken as more than a starting point into the investigation.

    Also consider: a) The halo effect of conventional farming practices on the mostly insular organic farms.
    b) The reduced productivity of organic farming, so not a per area, but per weight of produce comparison should be used.
    c) The use of copper sulphate as a fungicide in the organic production of grapes and potatoes/tomatoes leads to a severe residue problem with this heavy metal in the soil. So, while it may not be a “more in weight” problem, it is a more in severity issue

    ( As an aside: d) Despite the heavy use of copper in grape production, due to its limited effect in adverse weather conditions, most of the organic wine production in Germany was wiped out last year. In a first world rich man’s game that is bearable, but when food has to be produced for feeding people in the developing world, such games are deadly.)

  5. As an agricultural consultant, I have worked with both conventional and organic farmers. The basic premis of both is “we don’t use a pesticide if there is no need to use it”.
    Pesticides are expensive and their application is equally expensive and the cost comes right off the bottom line. The conventional farmer has a greater choice that modern chemistry has to offer, (less residual, more targeted, lower toxicity). I grew up on a fruit and vegetable farm 1940’s – 1965 and we used the products that the organic growers are basically stuck with today.

    • I’ve heard specifically about PyGanic that this is deadly poisonous to humans, and requires a much heavier application compared to what a conventional farmer would use. I understand economics, but if two raspberry farmers get infested with the same pest, one being organic and one not, who is going to use more pesticide? And once those two crops end up on the grocery shelves, which would you prefer to eat? Have I fallen for the counter-mongering or is there truth to this mindset when you zero in on crysanthemum derivatives?

      • It has been years since I used Pyganic. But If memory serves without a synergist like Piperonyl butoxide, Insects will be knocked down by pyrethrin and can revive later on. Thus it is used at higher rates in organic formulations in order to avoid this. this may be what you are remembering.

      • I am not familiar with the product PyGanic. However if the maximum amount of any product used falls with in the regulatory guidelines, safety of the produce is ensured. The other often over looked factor is that the human digestive system is acidic whereas insects digestive system is basic. This makes a big difference in oral toxicity between humans and insects.

      • PyGanic is similar in toxicity to many commonly used conventional insecticides, but is far from being worse than many of them. It’s definitely one of the “harder” chemistries used in organic, but, if used as labeled, is not a threat to consumers. It breaks down fairly quickly, so it does need to be applied more frequently than many conventional insectides, and it’s not great for beneficial insects, so on those counts, it might be less preferable to some “softer” conventional insecticides.

  6. “Some” advocates for conventional agriculture? After working with tree and vine PCA’s for thirty years in California and being involved in various industry organizations representing both commodity groups and professional PCAs, I have never heard anyone make that argument. “Some” is an awfully weak premise upon which to construct a narrative.

      • So by “some” you mean people with no demonstrated familiarity with agriculture let alone credible expertise in that area? Would have been helpful if you named names or gave specific examples in your article, not after the fact. Otherwise, you are venturing dangerously close to straw man territory.

          • In the way you framed the argument, I don’t think “higher doses” and MORE pesticides are the same thing. As you know, many organic pesticides, things like sulfur, horticultural oils, insecticidal soaps, bordeaux, etc., are applied at much greater rates of a.i. per acre than many modern synthetic pesticides (often pounds or quarts vs ounces), but that is a different number compared to total amount of pesticide applied per crop cycle or year, which is how I interpret “more”. In the example above, I take issue with the “incredibly dangerous” part, at least, as a blanket statement, but there is some truth to “higher doses.”

            As you also know, amount of a.i. per unit area is a poor way of making comparisons and evaluating risk. Virtually meaningless, I’d say.

            I would also say that your examples seem like they are coming from folks who are fairly ignorant of current pest management practices, conventional or organic, so maybe you should have said “Some people who don’t know much about agriculture.” instead of “Some people.”

            Not off to a great start, but as always, looking forward to what you have to say next.

          • One of the problems here is that this is the introduction of a 7000 word essay, but it’s being treated as stand alone piece and people couldn’t jump ahead to the points they wanted to see made.

          • …but it’s being treated as stand alone piece and people couldn’t jump ahead to the points they wanted to see made.

            Maybe by others, but what I am saying is that I think you missed the mark on the specific premise of part one; nothing to do with other points I am sure you will make.

            Whether more or less pesticide is applied in organic production systems is irrelevant, and to listen to the opinions of so-called “advocates of conventional agriculture” who seem to be quite ignorant on this topic was an unfortunate waste of your time, in my opinion.

            I think using biodiversity in the way you did was also a complete waste of time; another meaningless metric for judging overall environmental impact.

            And finally, n = 8 all within shouting distance of the Canadian border where many insects don’t survive the winter, among other things. Really?

            If I saw anyone else write an article like this, multi-part or not, I would conclude they were just trying to fill space.

  7. May really be part of “Part Three” but here are some observations of my citrus orchard (IPM) vs my neighbor’s organic orchard, literally next door.
    There are several important differences (water, diesel, dust, etc.) I will limit it to pesticides. We are in a zone of infestation of the Asian Citrus Psyllid (ACP) which is the vector for the incurable HLB (Greening disease), so we both are required to spray for suppression of the ACP or the packing houses will not take our fruit. My orchard requires 2.5 applications/ year & we rotate the agent to prevent tolerance. Mr Organic has to spray 6-8 x/ year because the duration of activity is much shorter. Also last week CalAg scientists show evidence the organic program is not working at that level of intensity. We are all in deep poop.

  8. Interesting piece. In your same forum, however, I’ve come across comments from farmers with mixed crops discussing the extra passes required over the organic plots. Now, some may be referring to gm or conventional crops which would be expected to produce different results.

  9. Very skewed piece which distorts information to support your premise. Asking organic farmers…is not science. Anecdotes are evidence of nothing. I’ve asked plenty of farmers in my state and they laugh about paying certifiers/inspectors under the table for organic certification and do all sorts of practices that are not recognized as organic. Part of what makes organic chemical use more dangerous are some of the older chemicals used that are not regulated or “approved”, many containing heavy metals and are often applied more heavily because they are less effective than many modern chemicals.

  10. As a PNW organic potato farmer of many years experience I rather doubt your farmers claim that he uses no insecticides on his potatoes. Unless he is a very small farmer and can control colorado potato beetle by hand he is very likely spraying something! Those little buggers are ubiquitous in the NW. love potatoes and are extremely difficult to eradicate without sprays of some sort.
    I’ve done this for over 40 years at scale and haven’t found a “silver bullet” yet!
    That said I am quite sure pesticide use on Organic farms is far lower than on the non O type so your thesis is, in my opinion, correct.

  11. Whie I appreciate the article, I think you could go one step further to obtain some very detailed data.

    We have 100 acres of blueberries in Oregon, east of Eugene. We are certified organic by Oregon Tilth. Besides annual inspections (3-4 hours going over paperwork and fields) they make random visits to take leaf and fruit samples to check for herbicide and pesticide use. There is no “lying” about what you use when they run about 300 substance tests on your plants. If residue from any of the substances is found an investigation is launched into why. These tests are for both approved and non-approved substances.

    I would imagine you could get very accurate data on herbicide and pesticide use from these certifying groups as I have to provide it to them in a very detailed manner. For example: if I spray Entrust as mentioned in the article, the product must be pre-approved and on my materials list, provide the date(s) sprayed, fields, amount/acre and label of the product.

    Once again, I would go directly to a certifying group and ask if they can provide the specific data that their organic farmers provide to them. The data is there, I know because I spend hours tracking it and submitting it.

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