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The innocent pyrethroids, perspectives from the bottom of the ag drainage canal

17 Jan
English: Pumping station A drainage channel le...

. (Photo credit: Wikipedia)

Hello, gentle readers,

I am writing to announce that I have actually started working in my field, or more precisely, in the canals at the end of the irrigation ditches at the downhill side of my field, and I am thrilled. My job is to sample water to help California growers comply with state and federal regulations regarding nutrient and pesticide loads in their tailwater. I have no skill getting my waders un-stuck from the mud, so I only hope one day to go pro, but this is my big chance, I think.

From a debriefing session at the company headquarters I learned that there are exceedences for two organophosphate pesticides, a family of pesticides effective against many insect pests and very soluble in water. Instead, to protect waterways from further contamination, farmers are switching to more frequent use of pyrethroids, a family of pesticides extracted from the marigold family of plants and effective against a narrower range of pest insects, namely the butterfly and moth family. Pyrethroids were considered safe because they bind to soil well and they break down fairly quickly, but if they do wash down into waterways on sediment particles, they are deadly to aquatic invertebrates, and they need to be used more frequently than their organophosphate predecessors. Is switching to pyrethroids really an improvement? I have my doubts.

Am I glad to be doing something about my passion for public access to environmental quality data? You betcha!

From the ditch,

Your faithful correspondent.


How much Aflatoxin can our beef and poultry handle in these stormy times? Senator weighs in.

1 Dec

The laws of supply and demand dictate that scarcity drives prices up. Corn and other feed grains are moldier than usual due to unusually stormy weather, making quality corn more scarce on the market, thereby driving corn prices up. The price of corn is also rising because of the increasing demand for corn ethanol fuel, a renewable, cleaner burning gasoline additive,., and because of a severe recent drought in the US midwest. Meat animals no longer bring in enough money to pay for their traditional, corn-based feed, so farmers and ranchers are reportedly sacrificing their herds to make ends meet.
Senator Roberts has a solution to this problem. Why not ease up on the regulations about feed grain quality? Why not  feed livestock a mix of moldy grain and quality grain, a mix that is designed to reach, but not exceed, the Food and Drug Administration’s maximum Aflatoxin concentration? After all, we have plenty of moldy grain this year, and plenty of hungry livestock. He understands that dairy cows should be given less aflatoxin than other types of livestock, and this should be considered when giving out aflatoxin waivers. More feed means lower feed prices and possibly more ranchers able to stay in business this year.

What are the risks to poultry, beef cattle, dairy cattle and consumers of overexposure to Aflatoxin? For poultry, aflatoxin reduces weight gain. For dairy cattle, aflatoxin has minimal effects on the cows but goes directly into the milk supply, putting human consumers at risk.

How much is too much aflatoxin in feed grain, according to the FDA? No harm comes to animals consuming 20 parts per billion of aflatoxin, but it is legal to use feed with up to 300 parts per billion of aflatoxin. The difference is due to the fact that resulting meat or poultry meets FDA standards for aflatoxin levels in consumer products. The compliance policy guidelines can be found here.

What about other types of fungal toxins? Why did Senator Roberts not mention Fumonisin, a more potent fungal toxin on corn and other feed grains? The FDA compliance policy guidelines on food and feed levels for this toxin are available here.

Since more aflatoxin-contaminated feed  will be on the market instead of being tilled under, will this result in increased risks of direct human consumption?

If Senator Roberts’ idea is adopted, for how long will the mixed grain waivers be available?  What if this decision were made permanent? Would long-term low-level exposure to these fungal toxins decrease our animal product yield and increase our long-term exposure to these dangerous fungal toxins?

You can email Senator Roberts, or write your own senator, if you have an opinion about his proposed solution to this critical feed shortage.


Subtle but potentially serious: health effects of low-level pesticide exposure

8 Nov

The Bing cherry owes its development to the Ch...

Reposted from The Pump Handle, a wonderful science blog that is associated with National Geographic Magazine:

Subtle but potentially serious: health effects of low-level pesticide exposure.

Stanford study about organic vs. conventional produce is taken out of context

13 Sep

A recent study by Stanford scientist C. S. Spangler et al. compiled the results of 20 previous comparisons of the nutritional and pesticide contents of organic vs conventional produce, milk and meat has been taken out of context by many. Here, for a limited time, please get  your free copy of the study and decide for yourself. Figure 2 shows unequivocally that organic produce contains less pesticide residue. For those of you who buy organic produce thinking that it contains more nutrients, this study might motivate you to buy conventional produce instead. However, for people who are concerned with pesticide residues, this study actually offers some evidence for buying organic produce. Restricted access to the article gives those of us with access the power to decide what  opinions you can have without ever seeing the data. In protest, I am posting this restricted access article for a short time so you can get the real scoop from the source. Please share  your impressions and conclusions from the data!


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Ploughshares into spray nozzles–the California Tour

6 Sep
English: Wild elephants in Munnar, Kerala

English: Wild elephants in Munnar, Kerala (Photo credit: Wikipedia)

How will farmers feed 9 billion people by the close of this century? That is the question posed to six renowned leaders in the field of conservation farming during the Conservation Ag Systems Innovation conference tour (CASI)
On August 28th, 29th and 30th,
Jeff Mitchell, University of California Cooperative Extension Specialist,  gathered together some of the world’s great visionaries to sell conservation farming practices to California farmers, students, and agency staffpeople. Conservation farming, a term used to refer to no-till, minimum tillage and controlled traffic farming practices, is popular in the midwestern US because it saves water and cuts fuel costs while preserving soil organic matter, which has many benefits to soil fertility. No-till is also popular in South America, particularly in Brazil, while controlled traffic farming (with conventional tillage) is practiced in Tasmania, an island off the coast of Australia, for the purpose of reducing soil compaction on the cropped rows while improving traction on the trafficked rows.

Don Reicosky from Morris, MN, a retired USDA ARS employee, explained the nuts and bolts of tillage and likened it to natural disasters for soil microorganisms. The best tillage is no-till, he explained.
Rolf Derpsch from Paraguay, who has worked in Brasil, Argentina, Somalia and Germany, explained why conservation tillage not only saves water but also reduces the need for fertilizer because soil microbes and organic matter act as a slow release fertilizer, protecting ground and surface water from contamination. He said that early adoption of no-till in South America was easier to support than here in the US because there was no initial attachment to what we call conventional tillage, and the yield increases with less gas and less fertilizer inspired the spread of conservation farming there.

Clay Mitchell from Geneseo, IA grows corn and soybeans alternating in a north-south direction to maximize profitability based on market prices for those two commodities, but that is not all. This farmer has combined controlled traffic farming with satellite GPS (Global Positioning System) technology, and an awe inspiring data collection protocol which allows him to micromanage the fertilizer application based on things like prior yield in a particluar square foot of field. Tillage has long been considered the primary way to get rid of weeds and make the fertilizer applications and rooting depth more uniform. With no-till, surface application of soil ammendments like lime (calcium or calcium-magnesium carbonates) could be inconsistent and will only reach a depth of a few centimeters during a growing season, so Mr. C. Mitchell advises crop rotations rather than tillage to incorporate surface applied lime at depth, and he relies on satellites to position his fertilizers exactly where they are most needed rather than tilling for greater uniformity. This is a real engineering problem solving strategy, but weed control

Jerry Hatfield spoke about what the EPA and the California Air Quality Control Board want from soil, and how much more food we will need to produce on the same land. These two ideas do not conflict–by keeping more carbon on the ground, soil water holding capacity goes up, meaning that less irrigation water is needed and droughts are less severe. Water use efficiency increases as does productivity per unit fertilizer, giving us some hope for the future, when worldwide land area will decrease while demand will be as high in the next 10 years as in the previous 100 years.

John McPhee of Burney, Tasmania explained how GPS technology can aid in controlled traffic farming which reduces erosion and compaction, improving drainage and allowing cultivation and planting sooner after rain events. He said that tillage was an integral part of his operation and it was not popular to consider no-till systems in Tasmania. He likened the soil microbes to an elephant per acre, and the residue left in the field as food for the elephant -FEED the Elephant!

I would like to suggest that there was another elephant in that room. Herbicides. There is no such thing as organic no-till. Tillage is a wonderful alternative to herbicides and with all the hype about overuse of Roundup and other easily available potent herbicides, which results in herbicide resistance in common weed species such as Palmer Amaranth. Mr. Clay Mitchell of Iowa explained that he rotated his herbicides by rotating his GMO corn and soybeans from Roundup Ready varieties to Liberty Link varieties (the first can tolerate lots of the herbicide Roundup, or Glyphosate, and the second can handle a lot of Glufosinate, an herbicide with a different mode of action. Rotating modes of action is smart to prevent resistance in weed species, but mechanical control is the only option for organic growers, so if we stop plowing, we protect the environemnt from carbon dioxide and particulate matter but this system depends on constant innovation of herbicide chemistries to keep up with herbicide resistance, and constant new developments in the world of GMO’s to allow excessive herbicide applications. The herbicide question looms large in my mind, particularly for the developing world, where transportation infrastructure increases the cost of everything from fertilizer to herbicide to parts for fancy GPS directed no-till equipment. So feed the soil microbial elephant, and give that herbicide elephant a few peanuts too, while you’re at it–the future of humanity and food security depend on it!


Sweetcorn: A chemical war zone. We are not just spectators any more.

28 Aug
Fusarium ear rot on maize

Fusarium ear rot on maize (Photo credit: CIMMYT)

It”s sweet corn season, and farm stands are popping up all over the country to feed the need. So where do you go for your sweet corn? Organic or conventional? Do you grow your own corn?

This time of year brings back memories of my days working on an organic farm and roadside stand where customers could pull in and yell out the window ” got any corn?”, and I would run out into the field and snap off a ripe ear, opening the husk and cracking off the top inch or so of cob to get rid of the earworm and damaged kernels at the top of nearly every ear that I picked. We told customers that ‘if they were handy with a knife’, a little pest damage was easy to remedy and that organic produce was bound to have some pest damage. In particular, we believed that a damaged organic ear of corn was safer to eat than a conventional ear harboring pesticide residue.

I took this experience to my next job interview, another seasonal farm labor job in Wisconsin at a ‘you-pick’ vegetable operation, where the owner scoffed at my experience on an organic farm, saying that pesticides were far less toxic than naturally occurring fungal toxins, and that production in organic systems would never be enough to ensure food security due to high losses from pest damage. Needless to say, I did not work for this farmer, and I paid no attention to his words because he had lectured me, a complete stranger, for several hours in a manic monologue and I thought he was a fanatic. That summer I worked as a cashier instead and forgot all about him until I took a field plant pathology class this year. Incredibly, this ‘fanatic’ who did not hire me was right, at least in the case of sweet corn.

Truths about natural fungal toxins on sweet corn that can kill you:

1. Since the 70’s, we have known that a fungus called Fusarium ear rot produces a toxin called Fumonisin that is directly linked to pancreatic cancer in humans and various other cancers in livestock. This is a fact that is poorly publicized and is more of a problem in humid environments that favor fungal growth, and the toxin is found in apparently healthy kernels as well as obviously infected kernels (Wild and Gong, 2010)

2. The fungus produces more of this potent carcinogen as the season goes on, with the highest concentrations near the end of the season (Picot-et-al. 2011)

3. Controlling caterpillar pests such as corn earworm or army worm provide some measure of control against Fusarium ear rot because the fungus is a secondary invader whose spores gain access to the ear by means of the bore hole made by the caterpillar. There are many ways to control caterpillars, and one of the most controversial is genetically modified (GMO) Bacillis Thurnigensis (BT) corn, which makes a bacterial toxin that kills caterpillars, turning them from healthy hungry larvae to stretchy black lines of tar(Wu, 2007). The main objection to this corn is that it contains bacterial genes. Organic corn growers can also utilize this wonderful chemical which is nontoxic to humans by spraying the actual bacterium on non-genetically modified corn varieties. Other options include spooning oil onto the silks of each unripe corn ear, a practice common before world war II, and spraying organophosphate, a chemical that is more toxic than either BT or oil and which is being phased out here in California due to its toxicity to aquatic insects. Of these options, oil and BT spray are options available to both organic and conventional growers. Whether produced by bacteria or by genetically modified corn, BT is much less toxic than Fumonisin toxin produced by ‘all natural’ Fusarium ear rot, and very likely stops Fusarium from entering the ear by killing the borer caterpillars before they can make the ear vulnerable to Fusarium attack.

Pesticide residues are higher in conventionally grown produce than in organically grown produce (Spangler et al 2012), but ignoring pests and pest damage entirely in an organic or a conventional system has the potential to invite natural toxins in which could pose a greater health threat.

Take home message: Organic pest damage isn’t always safe. Nature has had chemical warfare much longer than humans have been breeding crops and cultivating the land! An organic or conventional grower should stay on top of  insect pests in corn in particular because Fusarium head rot is much more frightening for human health than the pesticides used to kill the worms.


Picot et-al. 2011 The Dent Stage of Maize Kernels Is the Most Conducive for Fumonisin Biosynthesis under Field Conditions

Wild and Gong 2010 Mycotoxins and Human Disease-a largely ignored human health concern

Wu, F. 2007 BT corn shows less fungal infection

Spangler, C. S. et al (2012) Are Organic Foods Safer or Healthier Than Conventional Alternatives?: A Systematic Review. Annals of Internal Medicine 157:348-366

Advice for pesticide handlers and survivalists: Do not overestimate the power of a gas mask!

19 Aug
English: S10 Gas Mask Respirator Avon

English: S10 Gas Mask Respirator Avon (Photo credit: Wikipedia)

In studying the laws and regulations for pest control in the state of California, I came across a shocking pamphlet that made me worry for the safety of all those workers that have to spray volatile chemicals for a living, and even all those hairy mountain men that stockpile canned goods, weapons and, yes, gas masks, for the end of days. As a blogger, I am not encouraging or opposing this idea, but buying gas masks on line that are not fitted to your face and don’t accommodate any facial hair (if you have any), gives a person a false sense of security in the face of chemical exposure, so READ ON:

•If you have a beard, a bushy mustache,or long sideburns, a regular respirator won’t protect you because the mustache, beard or sideburns keep it from making a tight seal on your face. You need to use a special respirator.
•If your foreman doesn’t have one of these special respirators, you cannot do the work.”Excerpted from California Department of Pesticide Regulation‘s publication PSIS A-5.

For the rest of us who may be required to apply pesticides in the course of their employment, we may feel that well fitted gas masks provide complete protection against inhalation of fumes. Well, if that is what you have come to believe, keep in mind that one of the ways employers know when to change a filter is when YOU report an unusual smell or taste. READ ON.

Most respirators do not really clean the air.What they do is stop most harmful chemicals from getting into your lungs. They dothis with special filters. But these filters stop working after a while. Then the pesticide will pass through and you will breathe it in. If you notice a smell or taste, if your eyes or throat burn, or if it gets hard for you to breathe, leave the area RIGHT AWAY. Go to a safe area that contains nopesticides. Then take off your respirator and look at it carefully. Is it torn or worn out? If there are no cracks or other problems you can see, you may need to change the filter.
Because many pesticides do not have a smell or cause irritation, your employer must replace the filter often.
•when directions on the pesticide label say so, or
•when the respirator maker says it should be replaced, or
•when you first notice smell, taste or irritation, or
•at the end of each workday.
Follow the rule that replaces the filter soonest.
REMEMBER: Respirators only protect you from breathing chemicals. Most of the time when pesticides are used, protecting your skin is also important.”

Excerpted from California Department of Pesticide Regulation’s publication PSIS A-5.

Employers are required to provide complete information about the chemicals that you may be applying and their effects on you and the environment, and they are required as well to provide working, fitted protective equipment, including gas masks for volatile chemicals. If these excerpts frighten you or make you angry, read the fine print on the bottle,  ask questions, and don’t work with a chemical until you understand the risks–find your employer’s Material Safety Data Sheets for the chemicals that you apply and READ ON!!!

Pest management for your sweetie: Cacao Pesticide Public Relations poster–Thoughts?

22 Mar
A Russell Stovers box of milk chocolates.

A Russell Stovers box of milk chocolates. (Photo credit: Wikipedia)


An industry poster (above) shows a picture of a heart-shaped box of chocolates with all but one of the chocolates missing, a vivid depiction of the impact of pests, particularly a fungus commonly known as black pod disease, has on this tropical crop where no pest control is applied. The poster advocates for “modern agricultural approaches”, implying that the chemical industry should be thanked for the rest of the box of chocolates in the image, the chocolate harvest to which we have become accustomed (example at right).

I researched the pest management options available to cacao growers and found that black pod disease is one of the primary pests in cacao, resistant varieties of the crop are not resistant enough to ward off the disease, beneficial fungi such as Trichoderma give about 50% control of the pest, but fungicides like Kocide give almost complete control of the pest.

1. What is this fungicide, Kocide? Copper Hydroxide.

2. Who makes it and what kinds of precautions should be taken when using this material? This is a basic salt of copper and it is most hazardous if you inhale it, causing lung and kidney problems. It is also very hazardous to inhale as a gas if it were exposed to fire. Handlers should wear long sleeves and protection against breathing the wettable powder or the spray.

3. Does it harm nontarget species? How long does it stick around? Copper hydroxide is very toxic to aquatic invertebrates like daphnia, the classic ‘canary in the coal mine’ of water bugs. This substance should not get into waterways, and empty containers need to be disposed of as hazardous waste because it is a heavy metal and is regulated as hazardous waste. Copper binds tightly to the soil and may reside there for a long time in a not-very available form, but repeated use of this pesticide might result in buildup of this naturally occurring metal in the soil.

OP-ED: What are the implications for chocolate growers around the world?
Deberdt’s article mentions that most farmers in Cameroon, a cacao growing country, cannot afford the chemical fungicide and may experience up to 100% loss of their crop, validating the poster’s depiction of the losses that the untreated disease can cause. Copper hydroxide is a real option for improving yields and livelihoods of these farmers and they probably would use it if they could afford it. Biological controls like beneficial fungi might be a good compromise because they have some carry-over effects to the following year, so farmers can buy them every few years and get some relief from the black pod disease. I actually do agree with this industry poster and feel that this particular fungicide, if used away from waterways and if care is taken to prevent inhaling this product, can make a big difference in the lives of growers and I will still eat cacao!

Well-Water Consumption and Parkinson’s Disease in Rural California.

4 Mar

Why are there no pesticide well water standards? I have spoken to landowners who would rather not have their well water tested for fear that their property values will go down. Aquifers are connected.

Gatto NM, Cockburn M, Bronstein J, Manthripragada AD, Ritz B, 2009 Well-Water Consumption and Parkinson’s Disease in Rural California. Environ Health Perspect 117(12): doi:10.1289/ehp.0900852

Why it is important to read the herbicide label for recommended rate and ‘INACTIVE’ ingredients . . .

29 Feb

How many people read the label before going out and spraying the weeds in their back yards? Home owners are renowned for believing that if some is good, more must be better. Do they use protective gear like long sleeves? “In the summer? Are you kidding? No way!” What about the inactive ingredients? Obviously if they are inactive ingredients they must be less toxic than the active ones, right? WRONG!
A few weeks ago in my Weed Science course at UC Davis (a fabulous class, I recommend it highly), I learned that much suffering could have been averted if only Agent Orange were made more carefully, without as much Dioxin (a very hazardous contaminant that was not needed for defoliation, but was sprayed right along with the defoliants during the Vietnam War).
In a 5 part series, the Chicago Tribune Watchdog column story goes into some depth and interviews victims of this manufacturing oversight.

Check it out. Why is this not taught in history class? We have enough chemistry to understand this in high school. Please give us your 2 cents on this one!!