"Organic" pesticides and fungicides

[Pan]

In this thread, Fat Guy mentioned pesticides used by some organic farmers and provided a link to this page on organic farming, which includes the following text:

What synthetic materials does the NOSB [National Organic Standards Board] recommend for use in crop production?

Petroleum oil and soaps are allowed for insect control because of their benign nature to people and the environment. They also do little harm to beneficial insects.[...]

Various other more innocuous-sounding insecticides and fungicides are mentioned.

Is petroleum oil really so benign to human beings? I mean, you wouldn't want to eat crude oil, right? Anyone know whether parts of a plant that are meant to be eaten by human beings ever get petroleum sprayed on them by organic farmers? And if so, how could the stuff be washed off without using soap and dealing with soap residue?

Incidentally, yes, petroleum is of course made up of organic compounds, but "made of of compounds containing carbon" is not the usual standard for "organic" farming, is it? Because by that standard, all vegetable and animal matter is organic, and lots and lots of inedible and poisonous compounds are organic (which, in a chemistry-definition sense, is true).

[Fat Guy]

This report, produced by the conservative think-tank The Hudson Institute, presents the most emphatic form of the skeptic's argument about organic farming and pesticide use. Some interesting fodder for debate:

....it is important to address the common misperception that organic farming is “pesticide-free.” Organic farmers are allowed to use a number of toxic chemical pesticides, and many organic crops are routinely sprayed with pesticides.

The fundamental difference between organic and synthetic pesticides is not their toxicity, but their origin—whether they are extracted from natural plants, insects, or mineral ores or are chemically synthesized. In fact, some organic pesticides have mammalian toxicities that are far higher than many synthetic pesticides.... While organic farmers promote their use of non-chemical pest control strategies, such as crop rotation and beneficial insects, they still use chemical pesticides when pests threaten their crops.

And

It is true that organic farmers use crop rotation, disease and insect-resistant crop varieties, and soil fertility management to maximize plant health and minimize the impacts of crop pests—but the effectiveness of these strategies is quite limited. All farmers use a combination of crop rotation, disease and insect-resistant crop varieties, and soil fertility management to maximize plant health and minimize the impacts of crop pests. But all farmers also combine these strategies with judicious pesticide use to achieve an acceptable balance between crop yield, pest damage, and profitability. The biggest difference between organic farmers and their conventional counterparts is that organic farmers generally accept higher amounts of crop damage and loss before using pesticides. They do so because of the price premium for organic food and because organic pesticides are generally more expensive and less effective than their synthetic counterparts.

[ExtraMSG]

I imagine there are different levels of complying with the "spirit" of organic farming rather than just the "letter". But it's a good point to recognize because certainly much of organic farming complies only with the letter in order to qualify for a somewhat faulty label.

Reminds me of the issue with natural/artificial coloring and flavoring where you get things like squished bugs being used to color things red under the notion that natural colors must be inherently better than artificial colors.

Of course, the distinction can get quite blurry like it is with the pesticides issue above.

[fifi]

My sister and I have gardened "organically" for about 35 years. So did our mother and our grandmother. I put organically in quotes because there is no way that you can let Mother Nature rule and ever eat anything. Mother Nature is a bitch. Uuuuhhh... That is what a farmer or a gardener does... Try to outsmart the bitch.

Someone tell me what the difference is between grinding up that innocent looking daisy and spraying it on the tomatoes and buying that bag of pyretherin dust. Yes... pyretherins come from a daisy. Another favorite pesticide from "the good old days" is nicotine. Both of those "natural" compunds are pretty potent and kill bugs quite well, thank you. Good ones included.

The best you can do is take care of your soil, make your compost, encourage those earthworms, etc. etc. etc. But most gardeners can't turn a bunch of ducks loose in the garden like my grandma did to keep the bug population down. Even with her ducks, sometimes the hoard of grasshoppers would come through and the choices were... spray the SOBs or lose the garden.

The principles and intentions of "organic farming" are noble and in the right direction. But if you have never actually tried to do it, in some purist sense, you don't know what you are up against. At least not in the Gulf Coast where the bugs have an advantage. They almost never freeze to death.

[jsolomon]

Don't forget, there is the other other method of organic farming that works great on a small scale. You can control bugs and some plants with various animals such as ducks, turkeys, chickens, and geese.

However, this is only feasible on the scale of a large garden, perhaps up to a few tens of acres (yeah, so that's a really darn big garden).

Fifi's right. Even here in Nebraska, it's damned hard to keep the grasshoppers down. We just got a few days of subzero weather, and those SOB's with still be back next year.

Okay, I just read the regs, and as a chemist, I'm on a bit of a soapbox next. Read at your own risk.

There are sections in the regs from National Organic Program that really chap my ass. If we start at page 427, section 205.601 where they have the sythetic substances and following that, the nonsynthetic substances allowed. Can someone please give me a lucid argument why you can only use glycerin of non-synthetic origin? Glycerin is glycerin. It doesn't matter whether it came from olive oil, avocadoes, cows, or a factory. The stuff is still 3 carbon atoms 6 hydrogen atoms, and 3 oxygen atoms. There is no difference in how any of them act chemically or physically. Not one iota or epsilon.

There is bad science and much NIMBY (not in my backyard fear) wrong-headedness that I see from reading those recommendations. I am disappointed in this program. It should be overhauled or scuttled. These regulations are shit.

[/soapbox]

[slkinsey]

It is worthwhile to point out, while we're at it, that all the most potent toxins known to humankind are of "natural" origin (which is to say, produced by animals, plants, bacteria, etc. as opposed to chemical reactions in a laboratory or factory).

[Pan]

Thanks for the interesting responses.

I'm still interested in knowing how much of a problem petroleum oil could be, though, and how organic farmers are using it.

[fifi]

I think I remember my grandma using a mixture of lye soap and kerosene to wash off spider mites. (Those things are killers in our climate.) We always had kerosene around for the lamps in the houses at the bay compound that didn't have electricity. You had to spray it on, wait a few minutes and then wash it off or it would burn the plants. The kerosene will break down in the soil, eventually all the way to carbon dioxide and water so it goes away. When you think about it, "petroleum oil" (whatever is meant by that) is a natural product. Products called "dormant oil spray" may be what they are talking about. It is a common treatment for fruit trees here but can only be used in cool weather. It smothers the buggers.

One of the differences in the way we have used various sprays or other methods is that we don't do it indiscrminately. If we see a problem we deal with it, in the gentlest way possible. Companion planting, mixed crops and other tricks help a lot. But sometimes you gotta do what you gotta do.

I remember my sister and I debating for a couple of hours whether or not we were going to throw some of the pyretherin daisies in the blender and spray the squash plants that were under attack. We were mightily concerned about the honey bees.

[jsolomon]

Actually, the kerosene won't break down. It will simply evaporate and drift away.

I tried to post this earlier, but the DNS changes munched my reply.

The issue with petroleum is it used to be used as a solvent for many things like lye, or DDT. However, kerosene and diesel fuel, two of the most popular, will cause chemical burns to the plants.

Now, a lot of the concern is about solvents that are manufactured from petroleum. Things like ethyl acetate, chloroform, diethyl ether, dimethyl sulfoxide, and a zillion others.

What I don't understand is why some things are okay from biological sources, but the same chemical is banned if it is manufactured from petrol. It just doesn't make chemical sense to me.

Otherwise, organic farmers typically use petroleum oil for fuel and lubricants in their machinery.

[fifi]

Actually, the kerosene won't break down. It will simply evaporate and drift away.

That is true of most of it. But there is a lot that is adsorbed (notice the "d") to the soil particles. Many years ago I participated in a study looking at the breakdown of various petroleum products in soil. South Louisiana swamp soil works great.

Soil is amazing. For a project one time, I isolated a bug that uses phenol as its sole carbon source. I found it outside of the biology building where the cleaning ladies were in the habit of dumping their Lysol mop water.

[Pan]

What I don't understand is why some things are okay from biological sources, but the same chemical is banned if it is manufactured from petrol.  It just doesn't make chemical sense to me.

That confuses me, too. Gasoline is derived from crude oil, which is a naturally-occurring organic substance. But I guess it's the manufacturing that's the problem? Nah, kerosene is also manufactured from crude oil, right?

[Pan]

I remember my sister and I debating for a couple of hours whether or not we were going to throw some of the pyretherin daisies in the blender and spray the squash plants that were under attack. We were mightily concerned about the honey bees.

Is pyretherin an indiscriminate pesticide that kills bees?

[jsolomon]

That confuses me, too. Gasoline is derived from crude oil, which is a naturally-occurring organic substance. But I guess it's the manufacturing that's the problem? Nah, kerosene is also manufactured from crude oil, right?

I was making a distinction between strictly organic, only meaning that there is carbon in the structure, versus something that is actively manufactured in the cell by something easily defined as alive.

For instance, ethanol from glucose inside yeast = good

But, ethanol from ethane inside New Jersey factory = bad.

That doesn't make chemical sense to me.

Ethanol is ethanol is ethanol.

[jsolomon]

Soil is amazing. For a project one time, I isolated a bug that uses phenol as its sole carbon source. I found it outside of the biology building where the cleaning ladies were in the habit of dumping their Lysol mop water.

Wow! I want to see the cytochrome that oxidizes phenol!

[Pan]

I was making a distinction between strictly organic, only meaning that there is carbon in the structure, versus something that is actively manufactured in the cell by something easily defined as alive.

For instance, ethanol from glucose inside yeast = good

But, ethanol from ethane inside New Jersey factory = bad.

That doesn't make chemical sense to me.

Ethanol is ethanol is ethanol.

I would agree.

[fifi]

I remember my sister and I debating for a couple of hours whether or not we were going to throw some of the pyretherin daisies in the blender and spray the squash plants that were under attack. We were mightily concerned about the honey bees.

Is pyretherin an indiscriminate pesticide that kills bees?

Yep. In fact, bees are particularly susceptable.

(I have to look up the proper spelling. I don't think we have gotten it right yet. )

[fifi]

Soil is amazing. For a project one time, I isolated a bug that uses phenol as its sole carbon source. I found it outside of the biology building where the cleaning ladies were in the habit of dumping their Lysol mop water.

Wow! I want to see the cytochrome that oxidizes phenol!

Unfortunately, the semester came to an end before we got the bug classified. It took most of the semester confirming that it was using the phenol as a carbon source. That takes some pretty picky culturing techniques. I think it was some sort of pseudomonas but that was long ago.

[FistFullaRoux]

Is petroleum oil really so benign to human beings? I mean, you wouldn't want to eat crude oil, right?

The guy who "discovered" petroleum jelly (originally made during the oil pumping process) swore by the stuff, eating a spoonful every day for the rest of his life - at least according to the legend I have heard and read. Old folk cures involving diesel or oil in some form abound.

It might not kill ya, but it don't taste so good...

[Pan]

It might not kill ya, but it don't taste so good...

[fifi]

pyrethrum

Whew... glad that is settled.

[McAuliflower]

I was recently sleuthing around sciencenews.com and found this lovely little article:

Organic Doesn't Mean Free of Pesticides

Janet Raloff

In the United States, farmers treat most crops with pesticides to increase yields and the foods' eye appeal. Inevitably, studies have shown, traces of these pesticides remain on the food after harvest and are in the food we eat. However, switching to organically grown produce for as little as 2 weeks eliminated urine residues of potentially toxic organophosphate pesticides in children, a recent study reported (SN: 9/24/05, p. 197: Available to subscribers at http://www.sciencenews.org/articles/20050924/fob6.asp).

People might be tempted to read that study's findings as suggesting that organically grown fruits and veggies are free of potentially toxic pesticides. In fact, the researchers tested only for a few pesticides—those currently approved for use on foods in the United States.

In contrast, an undergraduate chemistry student, in a separate small-scale study, recently screened veggies for a number of banned pesticides and made an interesting discovery: The chemicals showed up on both conventionally grown and organic veggies—in roughly comparable amounts. In fact, organic carrots had higher amounts of some chemicals than the conventional vegetables did.

rest of the article...

So, we can't exactly avoid the pesticides after all?

Edited March 19, 2006 by McAuliflower (log)

[Patrick S]

I was recently sleuthing around sciencenews.com and found this lovely little article:

Organic Doesn't Mean Free of Pesticides

Janet Raloff

In the United States, farmers treat most crops with pesticides to increase yields and the foods' eye appeal. Inevitably, studies have shown, traces of these pesticides remain on the food after harvest and are in the food we eat. However, switching to organically grown produce for as little as 2 weeks eliminated urine residues of potentially toxic organophosphate pesticides in children, a recent study reported (SN: 9/24/05, p. 197: Available to subscribers at http://www.sciencenews.org/articles/20050924/fob6.asp).

People might be tempted to read that study's findings as suggesting that organically grown fruits and veggies are free of potentially toxic pesticides. In fact, the researchers tested only for a few pesticides—those currently approved for use on foods in the United States.

In contrast, an undergraduate chemistry student, in a separate small-scale study, recently screened veggies for a number of banned pesticides and made an interesting discovery: The chemicals showed up on both conventionally grown and organic veggies—in roughly comparable amounts. In fact, organic carrots had higher amounts of some chemicals than the conventional vegetables did.

rest of the article...

So, we can't exactly avoid the pesticides after all?

←

No, of course we can't, for reasons that go well beyond mere contamination by sythetic pesticides.

In fact, let's suppose that tonight, while we sleep, an omnipotent being causes every last trace of synthetic pesticide to vanish from the face of the earth. What effect would this have on our total pesticide exposure? It would, theoretically*, reduce it by about 0.01%.

*The reduction would be theoretical, because it is possible that plants not protected by exogenous pesticides could increase their production of endogenous pesticides as a result of increased predation. We know, for example, that corn grown organically can have much higher levels of the carcinogenic mycotoxin fumonisin. This is because the organic corn plants suffer more damage from insect predation, and the more damage their is, the more mycotoxin-producing fungi colonize the plant.

The following is reposted from a previous thread:

99.99% of the pesticides we consume are endogenous, produced by the plants themselves as chemical defenses. Summarizing from Ames et al (1990) and Gold et al (2002):

1. The average American consumes about 1.5 grams per day of natural pesticides, which is about 10,000 the intake of synthetic pesticide residues, which is estimated at about 0.09mg/day.

2. Concentrations of natural pesticides in plants are typically in the parts-per-thousand or parts-per-million, while concentrations of synthetic residues are typically parts-per-billion.

3. Humans ingest 5,000-10,000 natural pesticides in their diet.

4. Cabbage, for example, contains about 49 natural pesticides, Lima Beans 23.

5. Until recently, no natural pesticides were tested for carcinogenicity using the same methods that are used to test synthetic pesticides. As of 2002, 37/72 (51%) have tested carcinogenic. By comparison, 79/194 (41%) of synthetic commercial pesticides are carcinogenic in the very same types of tests.

6. The following compounds are carcinogenic natural pesticides:

acetaldehyde methylformylhydrazone, allyl isothiocyanate, arecoline. HCl, benzaldehyde, benzyl acetate, caffeic acid, capsaicin, catechol, clivorine, coumarin, crotonaldehyde, 3,4-dihydro coumarin, estragole, ethyl acrylate, N2-γ-glutamyl-p-hydrazinobenzoic acid, hexanal methyl formylhydrazine, p-hydrazinobenzoic acid. HCl, hydroquinone, 1-hydroxy anthraqui none, lasio carpine, d-limonene, 3- methoxycatechol, 8-methoxypsoralen, N-methyl-N-formylhydrazine, α-methylbenzyl alcohol, 3-methylbutanal methylformylhydrazone, 4-methylcatechol, methyl eugenol, methylhydrazine, monocrotaline, pentanal methylformylhydrazone, petasitenine, quercetin, reserpine, safrole, senkirkine, sesamol, symphytine

Remember, there are 5-10,000 natural pesticides in our diet, and only 72 have been tested so far. This list will grow. As Ames et al (1990, p. 7777) point out: "it is probable that almost every fruit and vegetable in the supermarket contains natural plant pesticides that are rodent carcinogens."

Ames et al, 1990. Dietary pesticides (99.99% all natural). Proceedings of the National Academy of Sciences 87, 7777-7781.

Gold et al, 2002. Misconceptions about the causes of cancer. In: Human and Environmental Risk Assessment: Theory and Practice, D. Paustenbach, ed., New York: John Wiley & Sons, pp. 1415-1460.

[russ parsons]

interesting thread and i'm glad it got bumped because i'd missed it the first time. i've covered ag for a long time, i'm billed as "the california cook" and i am a great supporter of high-quality small farms (and even "eat seasonal/local", but i am extremely skeptical of organics, which shocks most people.

there is a terrific book called "agrarian dreams" by a santa cruz prof named julie guthman that analyzes (from a very sympathetic, quite liberal point of view) organic farming in california. it would be unfair to her to try to summarize her argument in just a few sentences because she sets up the context and explanations so well, but suffice to say that her subtitle "the paradox of organic farming in california" pretty much says it all.

a few things:

1) most of the best farmers i know are not organic, though they have adapted many organic practices. they reserve the right to spray when absolutely necessary. (this is important context given them Manichean "organic vs. heavy chemical" argument that is usually posited).

2) almost all of the good organic farmers that i do know freely admit that they do it primarily as a marketing device, hoping to use it to get a premium price for their produce (as opposed to believing that it is safer for themselves or their customers).

3) i think the "fine food world" (chefs/media, etc) did a great disservice to farmers by early on adopting the word organic as shorthand for high-quality small farming. they are not the identical. perhaps "artisanal" or some other such word is of more use.

[JohnL]

interesting thread and i'm glad it got bumped because i'd missed it the first time. i've covered ag for a long time, i'm billed as "the california cook" and i am a great supporter of  high-quality small farms (and even "eat seasonal/local", but i am extremely skeptical of organics, which shocks most people.

there is a terrific book called "agrarian dreams" by a santa cruz prof named julie guthman that analyzes (from a very sympathetic, quite liberal point of view) organic farming in california. it would be unfair to her to try to summarize her argument in just a few sentences because she sets up the context and explanations so well, but suffice to say that her subtitle "the paradox of organic farming in california" pretty much says it all.

a few things:

1) most of the best farmers i know are not organic, though they have adapted many organic practices. they reserve the right to spray when absolutely necessary. (this is important context given them Manichean "organic vs. heavy chemical" argument that is usually posited).

2) almost all of the good organic farmers that i do know freely admit that they do it primarily as a marketing device, hoping to use it to get a premium price for their produce (as opposed to believing that it is safer for themselves or their customers).

3) i think the "fine food world" (chefs/media, etc) did a great disservice to farmers by early on adopting the word organic as shorthand for high-quality small farming. they are not the identical. perhaps "artisanal" or some other such word is of more use.

←

That is the sanest and most reasonable take on this issue I have seen.

I couldn't agree more..

There's another ongoing thread here--"Is Wholefoods Wholesome?" that refers to a linked piece in Slate that looks at WF use of organic --in their marketing.

I think "artisanal" works for me.

Thanks for helping clear things up (a bit).