Tag: Gardening

Home gardening myths

Home gardening myths

There are so many ideas for improving your home garden that have grown up over the years, that it is difficult to keep them straight. And quite a few come from pretty reputable sources as Harter Landscaping who are specialized in this kind of work.

Soil inoculants

For example, I first heard about adding soil inoculant (nitrogen fixing bacteria) to the soil from Jim Crockett’s PBS program some years ago. The idea was that since legumes like peas and beans would utilize these bacteria to promote growth, but you still need to be careful for other minerals that grows around as the asbesto, is better to get a professional service as Asbestos Pros to remove it for the sake of the plants.

Beans
Beans

Well, you will find extension sites like this one at Penn State describing the use of soil inoculants, but they are clearly talking about full scale agriculture, not a home garden. But, according to Linda Chalker-Scott, who runs the Garden Professor’s Blog “There is absolutely no science behind using it in nonagricultural situations,” and that you should save your money. She notes that there are no studies that show such soil inoculation is useful in the home garden. Scott is also an Extension Professor at Washington State University, and the author of several gardening books.

Copper deters slugs?

slug_penny
Slug on pennies

Any number of writers have suggested that copper, even copper pennies can be used to deter slugs. They usually cite some unlikely sort of galvanic shock the slugs receive crawling over copper. This just plain doesn’t happen. In this article, you will see why that is silly, as well as a movie showing it doesn’t work. And the amount of actual copper in a U.S. penny is negligible in any case.

This probably came from the idea of using sharp copper edging along beds, which would cut slugs who tried to climb over it. That will work, but copper is expensive. And sharp edging would do, though, as well as using diatomaceous earth, which contains fossilized remains of diatoms, a top of hard shelled algae. Be sure to get the grade designed for your garden, not for swimming pools.

Frankly, the best way to deter slugs in large garden beds is still metaldehyde, but it is dangerous to pets. In such situations, iron phosphate is also effective.

Saucers of beer will draw slugs to them and drown them, but unfortunately, they actually attract slugs, and have to be emptied daily.

A final solution for slugs is to keep some ducks. They apparently love slugs.

Marigolds deter nematodes

marigoldsIf I have a square bed with some space in the middle, I often stick a couple of marigolds there. It’s colorful enough, but the idea that it might deter nematodes or other bugs is only true when you plant them ahead of time. About 2 months earlier. This clearly only would work in long growing season regions like Florida. Marigold roots secrete alpha-terthienyl into the soil, which will kill nematodes when you plant your main crop. Otherwise, you are just decorating your garden and that is not such a bad idea.

In some cases, marigolds can become slug magnets, and the slugs will strip the marigolds. This is not very helpful.

Companion planting

The idea that planting various crops near each other, called “intercropping” seems intuitively appealing, but you will discover than there is simply no science behind it. As Linda Chalker-Scott describes on her Horticultural Myths page, there is little science behind companion plantings.

The “Three Sisters” planting associated with native Americans planted corn, beans and squash together, so that the bean vine climbs the corn and the squash fills in the ground space. This only works because the three plants have similar growing requirements and don’t out-compete each other for nourishment.

Beyond that one case, much of the writing on companion plantings borders on pseudo-science and the occult, she notes, and “traditional lists of plant associations have entertainment, not scientific value.”

Trap cropping is a special case of intercropping, where you plant a crop a couple of weeks ahead of your main crop, so that it attracts the pests away from your cash crop, you can also hire a wasp exterminator cincinnati if you feel you have problems controlling pests from your garden. In the linked paper, the researchers note that planting Blue Hubbard squash ahead of your main squash or cucurbit crop. This will attract the squash vine borers and cucumber beetles to the trap crop, and you can then plant your squash or cucurbit seeds. This probably is not relevant to home gardening, though.

Bone Meal

Bone meal  (according to Dr Chalker-Scott)  is primarily calcium and phosphorus, which are usually available in garden soils in sufficient quantity. So when you plant your spring bulbs, you might as well skip buying the bone meal. The only thing it might do is induce your dog to dig them up.

Compost tea

You make a compost tea by mixing compost with water, letting it soak and then straining through cheesecloth or the like and using it in your garden. You may recognize that this description is very vague and thus the results are quite variable. While there is some research suggesting that compost teas may deliver soluble nitrogen as fertilizer, creating such a tea really requires a laboratory rather than home brewing. And there is a significant danger of human pathogens in the resulting solution. I recommend having the best watering system there is, click over here if you want to get the best quality of water as possible, and don’t worry if there is any water damage at your house you can contact water damage restoration phoenix, they will take care of it.

Papers on the Horticultural Myths page suggest that compost teas

There are any number of other myths debunked on the Horticultural myths page and in the books below. They are fun to read.

Bibliography

  1. Linda Chalker-Scott, How Plants Work
  2. Linda Chalker-Scott, The Informed Gardener Blooms Again
  3. Jeff Gillman, The Truth About Garden Remedies
  4. Jeff Gillman, The Truth About Organic Gardening
  5. Jeff Gillman and Meleah Maynard, Decoding Gardening Advice
  6. Horticultural Myths
  7. The Garden Professor’s Blog
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Teaching organic farming in the classroom

Teaching organic farming in the classroom

According to the California Foundation for Agriculture in the Classroom grants of up to $1000 are now available for teachers to “creatively enhance the understanding of organic agriculture for kindergarten through eighth grade students.” The purpose is to integrate organic agriculture into regular classroom instruction. The grants are jointly supported by the California Certified Organic Farmer’s Foundation, and the application deadline is May 15, 2017.

From the scientists’ point of view, teaching students about organic agriculture would be intriguing because while historically, experiments led to the procedures, organic farming is essentially pre-scientific and much is based on the naturalistic fallacy.

However, there is a lot to be learned by studying the ideas and best practices of organic agriculture, and herewith we present an outline for an ideal curriculum.

Indore

Much of the earliest work by Sir Albert Howard at the Indore Farms he supervised in India had to do with the development of compost from vegetable and animal waste, and his first book in 1931, The Waste Products of Agriculture may have been his most important work. Howard noted that decomposition of compost only took place at neutral pH and added lime to achieve this. He believed that good soil aeration and quality humus were all that one needed to prevent disease, which was not supported by later scientist’s work, and his book, An Agricultural Testament contained a number of such ideas which caused him to lose support among botanists.

Sir Albert correctly believed that understanding of the mycorrhizae that lived on most plant roots was important and should not be left to mycologists, but his attacks on overspecialization in agricultural science as well as flaws in his later theories caused him to lose much of his initial scientific reputation, but this only increased his stature among non-scientists.

Lady Eve Balfour

Lady Eve Balfour was one of the first women to study agriculture at a British University and upon graduation she used her inheritance (she was part of the prominent Balfour political family) to buy farm land in Haughley Green in Suffolk, where she began experiments comparing her organic methods with conventional farming methods. Many of her experiments were published in her book The Living Soil in 1943.

Lady Eve was also the founder of the Soil Association, which although small in size, is a major proponent of organic farming in Britain, and she eventually donated her Haughley Green farms to the Association. She also attempted to moderate some of Sir Albert Howard’s extreme positions, but because of some of her other extreme spiritualist positions, Howard refused to join the Soil Association.

The Soil Association has also taken some extreme positions that are unsupported by science, suggesting that animals be cared for by homeopathic means (which cannot possibly work) and taken extreme positions on genetically modified crops which have no scientific basis.

J.I. Rodale

In the United States, Jerome Cohen, writing under the pseudonym of J. I. Rodale, took up promotion of organic farming and gardening with his Rodale Press and Rodale Institute, beginning in 1948, with his book The Organic Front, published by his own press. While Rodale promoted organic farming tirelessly, his views were hard to take very seriously because of his huckster style of writing:

Along comes your scientific agronomist, who should know better, but who recklessly throws a monkey wrench into this microbial universe, by dousing it with strong, corrosive chemical fertilizers. He believes that the conveyor belt method must be introduced into every aspect of farming.

Rodale took on all sorts on anti-scientific views, suggesting that the polio vaccine was a bad idea, and that rimless glasses and salt water cause cancer. He was also a racist. While he boasted that he would live to be 100, he died at 72, bizarrely during a taping of The Dick Cavett Show, although that episode never aired.

Rodale’s has also undertaken a study of organic versus conventional farming, which they published in a glossy brochure, but have never published in any peer-reviewed journal. An article by Pimentel and colleagues in Bioscience analyzes their findings: that organic and conventional farming techniques have similar yields and that in drought conditions, organic crops may do better. Pimentel also examined the economics and found that the two systems generated similar income, but only if you include a 10% organic price premium.

In another recent trial, they rotated their organically grown crop out and planted other soil enriching crops in 2 of the 3 years, and compared the yield with conventional crops grown without rotation. This was hardly a comparable trial.

The National Organic Program

Until the year 2002, farmers choosing to use organic techniques followed one of several sets of standards, but encouraged the USDA to set nation-wide standards so that organic crops would be comparable. The Agricultural Marketing Service within the USDA codified these standards as the National Organic Program, carefully noting that

Our regulations do not address food safety or nutrition. 

While the general fiction put about by the organic industry is that organic crops are grown without pesticides, this is demonstrably untrue, as there are quite a number of permitted substances listed as permitted. This is discussed in some detail by Porterfield.

Pesticides

Some consumers think that organic foods are somehow safer because they are not grown using synthetic pesticides, but plants make their own pesticides all the time and most of the synthetic pesticides in use are similar to the ones plants already make: toxic and carcinogenic in large quantities. But as Bruce Ames has shown, the plant-made pesticides occur at 10,000 times the concentration as the traces of pesticides added during farming.

Organic nutrition

You might think that organic crops grown with minimal pesticides and so forth might be more nutritious, but research has shown that there is essentially no difference. Dangour and coworkers systematically reviewed articles on nutrient content and found that “here is no evidence of a difference in nutrient quality between organically and conventionally produced foodstuffs.” Similarly, Brevata and Smith-Spangler “found little significant difference in health benefits between organic and conventional foods.”

Organic Yield

Since organic rules prevent the use of synthetic pesticides and fertilizers, you might ask if the yields differ between organic and conventional crops. There are a number of research articles indicating that organic yields are 50% to 80% of those from conventional farming. The diagram below is from de Ponti’s article “The crop yield gap between conventional and organic agriculture.”

COmparison yields

A similar gap was reported by Seufert. DePonti reported an average 80% organic yield and Seufert a 68% yield. And, the USDA’s report on yields was only a little better.

nov15_feature_mcbride_fig02

Carbon Footprint

When you plant and grow crops, and harvest them, you are taking away nourishment from the soil. You need inputs to replace those nutrients. In organic farming, this is usually composted manure and other plant debris. But the composting process itself produces greenhouse gases, as Savage notes. Farmers typically apply about 5 tons of composted manure per acre. In fact, the greenhouse gases generated for one acre are equivalent to those generated in manufacturing enough fertilizer for 12.9 acres. This doesn’t seem to be scalable.

Organic Farming causes more pollution

A study at Ben-Gurion University studied the groundwater runoff in a group of new greenhouses, some using manure fertilization and some using drip fertilizer irrigation. They monitored a zone well below the roots and just above the groundwater for nitrogen contamination, and found that nitrogen pollution in the groundwater was 10 times as much in the organic greenhouses as in those using drip irrigation to fertilize the plants.

No-Till Farming

One of the greatest advances in soil maintenance has been no-till farming, where the ground is not plowed up and turned over every season. When you use crops that are resistant to herbicides such as Roundup, you can kill the weeds before planting and plant using a seed drill without disturbing the soil. This preserves the soil structure and prevents soil runoff. Unfortunately, genetically modified crops that are resistant to herbicides are not currently permitted by organic standards. If soil care is important, this standard needs to be changed.

Organic Marketing

Organic foods are marketed throughout the United States by the Organic Trade Association, and the Organic Consumer Association (which regularly spreads misinformation). The definition of “organic” in the US is products “produced without the use of toxic and persistent pesticides and synthetic nitrogen fertilizers, antibiotics, synthetic hormones, genetic engineering or other excluded practices, sewage sludge, or irradiation. “ Since a number of pesticides have been approved for organic use, this is clearly misleading. The Environmental Working Group also is a major promoter of organic products, through its “Dirty Dozen,” which attempts to paint pesticide residues far below danger levels as being unsafe. It also clearly contradicts the findings of Bruce Ames we discussed above.

Thought Questions for Students

  1. What advantages do you see in organic crops?
  2. Are you concerned about pesticide levels on conventional crops?
  3. Why does the organic industry say that no pesticides are used?
  4. If a farmer has 1000 acres of farmland, and hopes to grow 160,000 bushels of corn, how much corn would he be able to grow if he switched to organic methods?
  5. If a farmer wants to make the same profit, how much would he have to raise his prices to grow organic corn on the same amount of land?
  6. Farmland is expensive. Would the farmer be justified in buying more land to grow the same amount of crops? Do you think there is unused farmland he can buy?
  7. In this article, Henry Miller argues that organic farming isn’t sustainable. Do you agree?
  8. In this article, Roger Cohen refers to organic farming as a “fable.” Is that fair?
  9. If you have a limited budget for buying food, as most of us do, would you be willing to pay 10% more for organic foods? How about 50% more? Why?
  10. Organic farmers can reduce their carbon footprint by using an Anaerobic Digester to compost their manure. How much do they cost? How big a farm do you need to pay for one?
  11. Roger Cohen argues that “organic” is actually just an ideology? Is that an exaggeration?
  12. How else could no-till farming work?
  13. By 2050, we project that only 2.5% of US cropland will be certified organic. Is that enough?

US Trend

‘The Third Plate’ : Dan Barber’s book entertaining but fallacious

third-plateDan Barber is a highly regarded chef with substantial experience who is known for his two restaurants, Blue Hill in New York and Blue Hill at Stone Barns in Westchester (Pocantico Hills). Both restaurants emphasize creative uses of vegetables and grains and de-emphasize meat, although their menus certainly include it, and represent some of the best examples of “farm to table cooking.”

His book, The Third Plate is an entertaining description of his restaurant and the accompanying farm give you some great insights into how great chefs think.  Unfortunately, his book has some serious fallacies that diminish its credibility as we describe later below.

Barber’s Pocantico Hills restaurant is located on the former Rockefeller estate. The renovation of the buildings as well as the accompanying working farm was funded by David Rockefeller, apparently to the tune of about $30 million. The book tells the story of how Barber’s Stone Barns restaurant developed in association with the farm, where they have the freedom to try out and breed unusual historical vegetables and grains. This “third plate” refers to an evolution in cooking from plates with meat and some small veggies on the side, to meat with better tasting and better cooked veggies, to some imagined future plate where the “steak” is made from vegetables and meat becomes a side dish. After the renovation, the cooks realized that the water they were using was far superior than before, this was because they installed a water softener. Check out WaterSoftenerGuide.com to learn how hard water is a problem.

Currently, Stone Barns offers one or two prix fixe menus, which for two with wine pairings, tax and tip can cost you as much as $898. With those prices in mind, you have to recognize that there are a lot of us who will probably never eat there. The reviews for that restaurant are exceptional and apparently so is the food. An evening’s dinner may consist of ten or more courses, starting with small servings of grains or vegetables, with meat in later courses. The menu varies frequently and may vary with each table depending on how the waiters feel you are appreciating what you have just been served

Barber is a good writer and story teller, and the book describes his work with the farmer and with plant breeders to develop and introduce the grains served in the restaurant, starting with the heirloom Eight Row Flint Corn, which was grown by early settlers but had all but vanished at the time he started.

His book is nominally divided into four sections: Soil, Land, Sea, and Seed, but the discussions flow freely around these ideas and you are likely to find some topics revisited in each section.

Foie gras

After his initial soil and farming discussions, Barber spends several chapters on foie gras, with a long bucolic description of a farm in Spain where geese are not force fed, but simply provided with sufficient food all summer and then naturally gorge on acorns in the fall. The farmer, Eduardo Sousa, simply talks to his geese to get them to do what he wants: and some call him a “goose whisperer.”

Then Barber visits the Hudson Valley Foie Gras company with Eduardo, and finds that the goose feeding is not cruel at all, where the “force feeding”  (gavage) takes only about 5 seconds per bird (ducks in this case). The kicker in this otherwise rather fascinating tale is that Eduardo decides that the Hudson valley ducks “didn’t know they were ducks.” And that Barber segues from that bizarre conclusion to his own: “What’s intolerable is the system of agriculture that it reflects.”

It is at this point that I lost touch with Barber’s point of view. Raising geese for slaughter one way or another, as long as they are humanely treated, seems to me completely comparable and I have no idea what he is getting at.

Fish Farming

Barber devotes over 100 pages to the sea and buying and cooking seafood sustainably, since many popular fish like bluefin tuna are threatened by overfishing. He visits the well-regarded chef Angel Leon of Aponiente on the Iberian Peninsula, who has learned how to cook the fishing fleet’s discarded by-catch, seasoning it with a phytoplankton broth. Barber also visits the fish farm Veta La Palma, where they raise fish in existing ponds and canals, where the fish are mostly fed from nutrients that occur naturally, producing some of the most sought after sea bass in Europe (and eventually the US).

He also describes the almadraba in Cadiz, where the villagers have been capturing migrating tuna using mazes of nets for hundreds, if not thousands of years.

He also spends some time praising Gilbert Le Coze, the founding chef of New York’s pre-eminent seafood-only restaurant, Le Bernardin, but for some reason avoids mentioning for many pages that Le Coze died in 1994, and that Eric Ripert, the chef since 1994, is principally responsible for Le Bernardin’s current exalted status in the food world.

Barber also tells us the story of Glenn Roberts and his founding of Anson Mills to produce artisanal grains, including graham flour (a kind of wheat) and revitalizing Carolina Gold rice, where they discover that the crops grown in conjunction with the wheat or rice affect the flavor of the grain.

Fallacies

While Barber’s book is entertaining enough to plow through in a day or two, there are some real problems with some of what he tells us.  Starting early on and repeating throughout is Barber’s insistence on the superiority of organic farming, although he provides no good reason for that, and does not acknowledge that “organic” is a USDA marketing label that allows you to charge higher prices rather than a set of superior techniques. At no point does he explain why the farm is “organic” nor why the farm would be less successful had they chosen careful conventional farming techniques.

Studies (USDA data) have shown that organic farming yield 50-75% as much as conventional farming, and that the produce is no safer or more nutritious or flavorful than conventional produce. This is simply the naturalistic fallacy promoted by the organic marketing associations.

One of the first anecdotes in the book describes farmer Klaas Martens, who had been farming conventionally for some years and suddenly developed a sort of weakness in his arms after spraying 2,4-D. According to the story, no doctors were able to diagnose his ailment, but this caused him to switch to organic farming because as his wife said, “he was being poisoned.”

The trouble with Martens’ story is that it contradicts all known toxicology data on 2,4-D. The National Pesticide Information Center fact sheet on 2,4-D says the “No occupational studies were found reporting signs or symptoms following exposure to 2,4-D under normal usage,” and even on acute oral exposure (drinking it) no symptoms like Martens had are observed. Since Martens condition was never diagnosed, we have to take this as mere rumor.

One particularly offensive statement later in the book comes from a young farmer who comes to Barber saying that “My father just got cancer, so I am switching to organic farming.”

Throughout the book, Barber continually mentions chemicals used in conventional farming as “poisoning the soil.” Since more than 98% of all farms in the US are conventional, this would imply that they must all be failing. Now, since most farmers have at least bachelor’s degrees and well understand how important caring for their soil is, this is pretty ridiculous. We would all be starving if this were true.

Even more ridiculous is Barber’s quote from Rudolf Steiner, who hatched the idea of biodynamic farming out of a series of mystical rituals, such as burying oak bark in a cow’s skull in the middle of your field. Steiner also had a lot of other crazy theories such as the one Barber quotes with a straight face, that the heart is not a pump for our blood, but that the blood that drives the heart. To support this nonsense he quotes “holistic practitioner” Thomas Cowan, who is deep into the same nonsense and Sally Fallon Morell of the discredited Weston A Price Foundation.

Barber is no friend of biotechnology either, making it clear he would never serve any genetically modified food in his restaurant (this is pretty hard to accomplish, actually). His example is the 2009 infestation of Late Blight that devastated everyone’s tomatoes in the Northeast.  There was one small patch of tomatoes on the farm that were not affected, Mountain Magic, an experimental seed from Cornell, bred to be blight resistant. (You can buy these from several seed catalogs today.) But Barber’s restaurant customers resisted them, fearing that they might be “genetically engineered.” He decided he needed to perpetuate the fallacy of tomatoes “bred the old-fashioned way at a land grant like Cornell, [versus] GM tomatoes from a company like Monsanto.”

The only GM tomato ever marketed was the Flavr Savr tomato, bred to be shipped ripe rather than green. Eventually, the tomato failed, but not because it didn’t have better flavor as Barber says, but because Calgene had trouble keeping costs down so it would be competitive.

Finally, Barber is skeptical about the whole idea of the Green Revolution, started by plant breeder and Nobel Peace Prize winner Norman Borlaug. His criticisms on the use of fertilizers to create higher yield seem to echo those of the mendacious non-scientific activist Vandana Shiva.

In fact, Barber is critical of the whole idea of modern agriculture, where farmers buy new seed each year rather than saving seeds from last year. Farmers have not saved seeds since the 1930s, because of the problems of storage and disease control as well as those of controlling new generations of seed. Barber thinks they should all be saving the best seeds from the fields each year on each farm instead, turning each farm into its own primitive seed development company. Few farmers would agree that this is a good division of labor.

In conclusion, Barber has written an entertaining and informative book on the relationship between high end cuisine and small scale agriculture, but seems oblivious to the fact that he and his restaurant are living a bucolic fantasy which can only work on a small scale, with the subsidies of the Rockefeller family and his high-priced restaurant.

Originally published on Examiner.com in September, 2014

 

Fresh tomatoes: open faced sandwiches

Fresh tomatoes: open faced sandwiches

Now that tomatoes have finally started to ripen, we can make our favorite summer sandwich, the toasted open faced sandwich. You could make them any time of year, but fresh garden tomatoes or equivalent ones from a farmer’s market are best. You want the flavorful kind of tomatoes that are raised locally as opposed to those bred to ship.

In our Connecticut garden, our favorite early tomato is Fourth of July, which was bred from cherry tomatoes. It’s growth habit forms clusters of smallish tomatoes, but way bigger than actual  cherry tomatoes. We also find that our paste tomatoes begin to ripen fairly soon thereafter we are growing Amish Paste and Opalka this year.  Finally, the Burpee Cloudy Day variety is the first full-sized tomato to ripen: it’s one you can slice for sandwiches. It’s also blight resistant.

If you can slice up a combination of these types to make a few sandwiches, you are ready to make open faced sandwiches. We start by lightly toasting the bread and buttering the toast lightly. Then we lay on the slices of tomatoes, about one layer or so thick.

raw

Then we put on strips of fairly crisp-cooked bacon, and top with slices of sharp cheddar cheese.  This order is important. For stability, the tomatoes have to go first, and put putting the bacon under the cheese, you prevent it from burning in the broiler.

The final step is, of course, to slip the open sandwiches under a broiler for a few minutes. This doesn’t take very long, so watch carefully. You want the cheese to melt, but don’t want anything to burn.

toasted

Serve immediately. It’s OK to use a knife and fork on these delicious sandwiches.

The Great Healthy Yard Project: a talk at the Wilton Library

Lewis' book
Lewis’ book

Last night we heard a talk by Diane Lewis, MD on The Great Healthy Yard Project (their web site is tghyp.com, run by Lewis from her home in Bedford, NY. Trained as a nephrologist (kidneys) and an internist, Lewis is not currently practicing medicine but devoting her time to promoting her project: reducing groundwater pollution by reducing the use of lawn chemicals. The talk was co-sponsored by Wilton Go Green, the Wilton Conservation Commission and the Wilton Garden Club, who introduced the speaker. The talk was recorded and will soon be on the Wilton Library’s website.

Lewis has also written a book on this issue with the same title, which is available on Amazon. She also has published articles summarizing her views in the New York Times and in the Baltimore Sun. A short 3-minute video on the tghyp website summarizes her position.

Lewis’ thesis is that “chemicals” from our lawns and gardens run off into the groundwater and eventually are found in our drinking water. As to which chemicals are of greatest concern, Lewis was quite vague as she mentioned none specifically. Were insecticides of more concern than fertilizers? Probably, but she didn’t actually say so.

She noted that the EPA is quite concerned about this runoff claiming that there is runoff in 70% of streams. The EPA does have a page with good and specific recommendations here. You can also find good descriptions of the problem at the US Geological Survey web site.

Lewis feels that this runoff into our drinking water is a serious problem and that it may be cumulative and could “damage our DNA,” although she presented no evidence for this somewhat surprising conclusion.

Endocrine disruptors

Central to her argument is that these (unspecified) chemicals are endocrine disruptors which even at very low levels may cause harm to humans. The whole idea of endocrine disruptors is controversial, however, and has not been definitively established.

The Endocrine Society has published two reports in this area. The 2009 report described the problem but noted that “Unfortunately, it is virtually impossible to make direct links between such epidemiological observations and exposure to given chemicals.” And, a key scientific paper in Science was withdrawn because of apparent scientific misconduct.

Needless to say, there are naysayers in this area, and one published by EndocrineScience.org criticizes the Endocrine Society, but this report was published by a manufacturer’s group, the American Chemistry Council.

Lewis suggested that these endocrine disruptors could be the cause of increased breast cancer, prostate cancer, diabetes, ADHD and autism, but really offered no science to support these views. When I talked with her afterwards, she said there were papers on rats showing that they take on autistic symptoms after treatment with some “chemicals,” but did not cite one specifically. She suggested that these chemicals could be one of many contributing causes, and this is borne out in papers (also here and here). But one problem with this hypothesis is that recent work shows that there has been no increase in autism occurrence in the past 30 years.

Confusion and misinformation

In her gardening segment, Lewis lost ground with reality by suggesting somehow that “eating organic food” would be beneficial, even though there is no evidence that organic food is more nutritious, tasty or safer in any way.  In fact, the classic paper by Bruce Ames showed that the toxic and carcinogenic pesticides generated by plants themselves were present at a level 10,000 times higher than any pesticide residues.

She also suggested that the decline in Monarch butterflies was caused by the planting of “GMO” crops, but backed off when I pointed out that large agriculture plowing fields to remove milkweed as well as eliminating by herbicide is the actual cause.  This whole issue is explained here by Amber Sherwood-K and Jon Entine. The slide that suggested that a solution would be “Don’t eat GMOs,” was thus complete nonsense.

She also went astray in suggesting that the WHO had declared that glyphosate (Roundup) was carcinogenic. In fact this was done by the IARC, a subcommittee of the WHO and in doing so they ignored substantial evidence to the contrary, as described in this report in Scientific American. And they have also found caffeine, alcohol, sunlight, and the hairdressing profession in that same category.

Meanwhile the German Federal Institute for Risk Assessment completed a 4-year assessment for the EU, considering 150 new toxicological studies, all available existing toxicological studies (more than 300) and nearly 900 peer-reviewed publications, concluding that

the available data do not show carcinogenic or mutagenic properties of glyphosate nor that glyphosate is toxic to fertility, reproduction or embryonal/fetal development in laboratory animals.

Gardening advice

In the last part of her talk she suggested growing more local plants that would require less care and fertilizers that could run off. Some of particular interest were cardinal flowers, Joe Pye weed and Monarda (bee balm).

We found it surprising that in this talk she avoided mentioning any “chemicals” by name, and she told us this was because this was a layman’s talk. Without naming them, she mentioned that some were listed in her NY Times article. These were glyphosate, carbaryl, malathion and 2,4-D. Of these, glyphosate and 2,4-D are herbicides of very low and relatively low toxicity. Carbaryl (also called Sevin) and malathion are moderately toxic to humans (and carbaryl to bees), but are generally used only in small amounts in gardens and probably are not major runoff candidates. Glyphosate binds to the soil and is seldom found in runoff.

During her talk Lewis had a great deal of trouble pronouncing bacillus thuringiensis, which might indicate that she is uncomfortable pronouncing these chemical names and thus leaves them out of her talks.

Overall, as a chemist, I was not happy with her demonizing the entire class of “chemicals” as all bad without any specific science to back up her assertions. However, her heart is generally in the right place in wanting to reduce runoff from suburban lawns into our water supply. We haven’t treated our lawn with anything in years, so we are way ahead of her, perhaps primarily because we are lazy or cheap, but our lawn still looks fine when it rains enough.

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