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Tuesday, February 7, 2017

The Many Ways Farmers Control Pests

The post originally appeared on the Putting Pesticides in Perspective (PPIP) Blog on 2/7/17 on which there are also 6 related sub-posts

Whether a farmer is growing in an organic or conventional system, his or her crop needs to be protected from damage from plant pests (insects, fungi, bacteria, viruses, nematodes, weeds…). To fail to minimize pest damage leads to inefficient use of scarce resources like prime farm land, water, or inputs. The quality and safety of the final products can also be compromised.
While materials we think of as “pesticides” play an important role, modern agricultural pest management depends on a combination of several tools and strategies which, when used together, offer a more resilient, economic, and effective means of crop protection. Though some of these practices have been part of traditional farming, many are more recent innovations. The explicit design of these multi-strategy programs began in the 1970s, and the approach is now widely adopted as integrated pest management (IPM). The optimal IPM program varies widely by crop and geography; this post will describe some examples that highlight the various components.

The approaches used to implement IPM programs generally fall into six categories:
  1. Avoiding the pest
  2. Employing the plant’s own genetic defenses
  3. Modifying the climate
  4. Disrupting the pest's life cycle
  5. Fostering beneficial organisms
  6. Using targeted pesticide applications
A brief introduction to each of the six approaches follows with additional links to the more detailed presentations. Each post will link back to the list above.
  1. Avoiding the pest
Not all pests occur in all places either because they have not spread there or because they cannot flourish in the climate of a given region. Both of these limitations have been historically important factors to consider when deciding what crops to grow where, and these pest limitations continue to be important considerations for farmers. Long-term, this strategy is limited by climate change and by the extensive movement of people and goods around the world
Plants fight back against pests by evolving a variety of defensive strategies controlled by genetic traits. Built-in genetic resistance is an attractive form of pest control for farmers, but it is a resource that requires considerable effort to employ and stewardship to maintain as an effective part of an IPM program. For some crops, farmers can maintain a seed bank of genetic variation and draw upon it to keep ahead of the pest’s inevitable tendency to evolve around plant defenses.
When genetic resistance is available, it is generally wise to complement it with other IPM elements, such as pesticides, to avoid losing the valuable traits. For many crops, conventional methods of breeding are too slow and/or complex to easily employ genetic solutions. Traditional and advanced grafting approaches offer a dual plant genetics approach that has been quite useful in many systems. Advancements in biotechnology allow farmers to use same-species resistance genes in hard-to-breed crops as well as novel genetic approaches that have shown considerable benefit in the few cases where they have been allowed to-date.
In some cases, farmers can shift the microclimate in which the plant is grown enough to reduce the threat of certain pests. Various degrees of protected culture have been widely used to shield crops from rain and/or to shift the temperature regime to extend the growing season at either end. The nature of the plant canopy can sometimes be managed to reduce humidity, increase light or otherwise create a microenvironment that is suppressive to certain pests.
Several strategies for pest control center on making it more difficult for the pests to reproduce. These range from crop rotation to insect pheromones to removal of damaged or infested plant parts. Other approaches involve the release of male insects which are sterile so that the females with which they mate do not produce any offspring.
Even pests have pests, and often there are ways that farmers can encourage these natural enemies to help keep pest populations low enough to obviate the need for other control measures. Sometimes, it is possible to actively produce and add the bio-control organisms to the system.
Farmers can use a wide range of crop protection agents as part of an IPM system. In a great many cases, these agents are low hazard options in terms of environmental, beneficial, or human impact, but the use of all such agents is highly regulated on a national and state level. These crop protection agents are often important for preserving the utility of other IPM approaches, particularly genetic resistance. Farmers have many economic and practical incentives to only use these materials on an as-needed basis.
Pest control in agriculture is a multi-dimensional effort, and pesticides are just one of the important tools that farmers employ. Some of these tools have been in use for a long time and some are new. With climate change, the control of pests will become even more difficult. As the global population grows and standards of living increase, it will be even more important for farmers to avoid the sort of losses and food waste that pest cause. Fortunately, the toolbox available to fight pests is diverse and constantly improving.

You are welcome to comment here and/or to email me at

Saturday, January 21, 2017

Whole Foods Wants To Sell You Slower-Growing Chicken. That Is Probably A Bad Idea

(This post originally appeared on Forbes on 1/20/17)

One challenge of being a modern food consumer is knowing what to believe or not believe in terms of food production narratives. There is a new campaign claiming that going back to older, slower growing chicken breeds is the right thing to do. There are some good reasons to reject that idea.

Most Americans enjoy eating chicken. On average we each consume about 90 pounds per year, a three-fold increase compared to per capita consumption in 1960. Chicken producers have kept up with this increasing demand even as our population has also increased. What was once a luxury food has become a very affordable option. Chicken remains an economically attractive choice for consumers, in large part because of increases in the production efficiency of modern chickens. Particularly in the last century, chicken farmers have consistently mated their best roosters with their best hens and steadily shifted their flock genetics towards more and more efficiency. Today, chickens are the most efficient of our meat animals in terms of how much grain it takes to produce each pound of final product. That also means more efficiency in terms of water and land use. Overall, this history is a good example of increasing sustainability.

While this progress has been a positive for consumers and the environment, there are some advocates saying that we should go back to using earlier, slower growing breeds of chickens. They claim that the rapid growth compromises the welfare of the birds and that slower growing chickens are a more ethical choice. The slow growth argument is that the weight gain of the chicken has outstripped its bone development so that the chicken becomes physically compromised, at least in the case of the birds kept around longer as breeding stock. In a recent article by Dan Charles for NPR, that concern seemed to be supported by William Muir, an independent animal science expert from Purdue University. I wrote to Dr. Muir and he said he had been misquoted. He and other industry experts say that chicken breeding has been simultaneously focused on weight and bone strength. 

By several objective measurements, modern chickens seem to be better off. Mortality rates are down substantially. The houses in which chicken are raised have better climate control and the flocks are protected from disease by vaccination.   Antibiotics were once used to improve gut health but that practice has been phased out. As of 2017 there is no longer any feeding of dual-use, animal/human antibiotics for growth promotion in chicken. This website has a helpful video about how chickens are raised.

The upscale grocery retailer, Whole Foods, is asking its suppliers to make the switch back to slower growing breeds. Some animal rights groups are putting similar pressure on the companies that supply chicken to restaurants. Is there really a conflict between sustainability and animal welfare when it comes to our most popular meat?

As consumers we would be wise to be skeptical about the assertion that fast growth is bad for the birds. Not everything you hear about chickens is true. For instance many consumers have been convinced that they should buy chicken labeled as not having added hormones even though no chickens are given hormones and haven’t since the 1950s.

Some of the ramifications of shifting back to slower growing chickens
Last week the National Chicken Council released a detailed report about what a change to slow-growing birds would mean in terms of resource-use and production costs. I pulled out some of the statistics that were most compelling to me as a crop scientist. In the hypothetical case that one third of the chicken industry switched back to slower growing birds, it would substantially reduce the overall supply of chicken for only a 14 day change in the growing cycle of the birds. The drop in feed-use-efficiency would mean that 33.5 billion more pounds of feed would need to be devoted to chicken production which would represent 670,000 tractor trailers full of grain. Currently each acre of grain (corn/soy) can feed 344 birds. The same amount will only feed 224 of the slow growing birds. That would translate into 7.6 million acres of farmland needed to support a 1/3 conversion. There are also ramifications for water use, the amount of manure produced (28.5B pounds), and of course the cost ($9B at the producer level and much more at the consumer level).

NCC is encouraging the foodservice and retail industries to fully consider all the economic and environmental ramifications of a potential change in chicken genetics. They are also supportive of research to objectively evaluate questions about animal welfare and health as effected by growth rate.

It is likely that some food industry players could profit from the creation of another up-sell category for meat. However it is appropriate to ask whether that is indeed a responsible path to take. Consumers have good reason to think this one through before going along with this marketing campaign.

You are welcome to comment here and/or to email me at

(Just to show that I take my chicken seriously, here is my favorite recipe for home made, dry rub chicken)

Tuesday, December 13, 2016

How Can Pesticides Be Safe?

Many people may find it difficult to imagine how a pesticide could ever be safe. To understand how that is possible, it is helpful to make the comparison with something more familiar: electricity.
It is hard to envision modern life without electricity. As much as we enjoy and need this source of energy, it involves some hazards. Electricity can, and sometimes does, cause injury or death.  Yet overall, we think of using electricity as a reasonably safe aspect of our lives.
Safety can’t be precisely defined. What we perceive as safe is something where the benefits more than offset the minimal risks. We can enjoy electricity’s benefits with little risk through two main strategies: 1) using low-hazard forms of electricity and 2) keeping ourselves from being exposed to hazardous forms of electricity.
The Low-Hazard Approach
Increasingly, we power the devices central to our lifestyles with forms of electricity that are practically non-hazardous. The prime examples would be our cell phones, Bluetooth devices, or portable music players that run on low-voltage, direct current electricity which is nearly incapable of causing us harm.  That same, low-hazard approach plays an important role in pesticide safety.
In the middle of the last century, a number of the early pesticides in use were chemicals that were quite toxic to mammals, and thus to humans. The U.S. began to seriously address the issue with the establishment of the U.S. Environmental Protection Agency (EPA) in 1970. Soon, the truly dangerous pesticides were removed from the market or their use was greatly restricted.
Since then, billions of dollars have been spent on the discovery, testing and regulatory review of new, far less toxic pesticide options. In the charts below, I’ve examined the toxicity of crop protection materials that have been used through looking at historical U.S. Department of Agriculture (USDA) data on Washington State apples and California pesticide reporting data from all crops in 2013. In these charts, the toxicity is based on feeding studies with rats or mice, which is used as an indicator of potential toxicity to humans. Other measures of toxicity have similar trends.
The EPA has four toxicity categories to classify the acute hazards of pesticide products. For use in apple orchards, the data show that pesticides from EPA Category I, Highly Toxic, were never more than 10% of the total pesticides used, and that their use has steadily declined. These would be pesticides as toxic as the nicotine that is sold for e-cigarettes. Only 0.2% of the pesticides applied to California crops in 2013 were in this category.

EPA Category II, Moderately Toxic, includes materials with toxicity in the same range as the capsaicin in hot peppers or the caffeine in coffee – familiar and even sought-after natural chemicals in our diets. That category represents very limited use on apples today, and only 18% of what growers applied in California apple orchards in 2013.
The pesticide use category that has grown is termed Slightly Toxic (EPA Category III). Toxicity for crop protection materials in this category is in the same range as the citric acid in a lemon or the vanillin in a vanilla bean.
The largest category of pesticides applied to apples and other crops today is Practically Non-Toxic for mammalian consumption (EPA Category IV). Comparing this to our use of electricity, we can see that low hazard is a major strategy through which we minimize pesticide risk.
To understand how something that is designed to kill or otherwise control a pest could be non-hazardous, consider the example of chocolate which has a flavor ingredient that we humans love but which can be toxic to our pet dogs. Chemicals can have different effects on different species. Scientists use the terms specificity and mode of action to describe how chemicals have their specific effects. With modern pesticides, the mode of action is normally the inhibition of some specific enzyme that is important to the viability of the pest. If the enzyme is inhibited by the pesticide, the pest might stop eating, stop growing and/or die.
That enzyme often isn’t one that even exists in humans and other animals ourselves or in other groups of organisms unlike the pest. A modern insecticide usually only affects enzymes that are found in insects or even a few kinds of insects. A modern herbicide might only inhibit an enzyme that is needed for the growth of plants. A modern fungicide inhibits an enzyme in a pathway of enzymes that is found in certain fungi. While all of these products should still be handled with a reasonable degree of caution, they are, like the electricity that powers our cell phones, low hazard and thus low risk. We can feel safe about their use.
Limiting Exposure Risk When There Is a Hazard
We still need the more hazardous forms of electricity (such as the 120 volt alternating current) for needs like lighting, heat, air conditioning etc. To minimize risk, we’ve developed safe guards such as systems of insulated wiring, childproof plugs, circuit breakers and GFCI outlets to keep us from being exposed to that hazard. Where we need 220 volt service, we have even more ways to avoid exposure. To be connected to the grid we need the extremely hazardous, high-voltage electricity coming to us from wherever it is generated. The high-power transmission lines are designed to make it unlikely that anyone will be exposed to that extremely hazardous form of electricity.
Some pesticides that we need to manage certain pests represent a possible hazard to mammals, like humans, or sometimes to other non-target organisms like birds, fish amphibians or aquatic invertebrates. The safe use of these pesticides is all about limiting exposure. For all pesticides used in agriculture, anyone who is directly involved in the mixing or application of the chemical must follow specific requirements regarding protective clothing and equipment. For low-hazard materials, that might just be gloves, closed shoes and a dust mask. For something that could be a significant human hazard, those restrictions would include a respirator and a protective whole-body TYVEC™ suit.
Restrictions can also dictate how soon after an application anyone can re-enter a treated field (re-entry interval or REI). For low-hazard pesticides, that time period can be a few hours or less. For more hazardous pesticides, the REI can be a number of days. For pesticides that are hazardous to fish or other aquatic organisms, restrictions mandate how close applicators can apply them to waterways. Similarly, for pesticides that are hazardous to bees or other pollinators, restrictions control when applicators can apply them relative to bloom times and/or times of the day when bees and other pollinators are working.
For all pesticides, the EPA conducts an extensive risk assessment and uses that information to set up a detailed set of restrictions designed to prevent the existence of any residues of concern to consumers by the time the crop is harvested. The details of this system are discussed in another post titled, Do I Need to be Concerned about Pesticide Residues on and in My Food?
The moral of this story: just like electricity, pesticides can be used in a way that meets our need for clean, productive farming while giving us a comfortable and functional level of safety.

Tuesday, November 22, 2016

Do You Really Need To Worry About Pesticide Residues On Your Food?

fresh fruits and vegetables
Some of the healthy fruits and vegetable we can enjoy (Image from Wikimedia)
Many Americans have concerns about pesticide residues on food – particularly for fruits and vegetables. In contrast with that oft-communicated perception, the safety of our food supply is well documented. One reason for this disconnect is that there are activist groups (non-governmental organizations) that consistently promote the idea that consumers should buy organic versions of certain crops in order to avoid pesticidesA recent study documented how that sort of message induces some lower income Americans to simply avoid fruits and vegetables all together. The truth is that our food supply is extremely safe because farmers are careful to use pesticides in ways that don’t lead to residue problems at the consumer level and because of rigorous regulation followed by farmers over the last several decades.
The common perception of organic as a safer option in this regard is also at odds with reality. The United States Department of Agriculture (USDA), which oversees organic certification, clearly states on its National Organic Program website: “Our regulations do not address food safety or nutrition.” Organic farmers can and do use pesticides from an approved list, but that list is not based on safety criteria. Organic growers are limited to natural chemicals and to a limited list of synthetic materials. As with any crop protection material, the EPA has the responsibility to evaluate and regulate their safe use. That oversight is why consumers can confidently enjoy both conventional and organic foods.
In this post I will describe the testing, regulatory and training systems that are in place in the US to protect consumers from risks associated with pesticide residues. I will also describe the intense monitoring system that demonstrates year-after-year that this system is working.
All farmers face challenges from a variety of pests and although they use a number of methods to manage those threats, pesticides are a critical part of that “toolbox.” The broad category “pesticide” includes certain chemicals that occur in nature as well as various synthetic chemicals. There are also pesticide products based on living biological agents. The responsibility for pesticide regulation is with the Environmental Protection Agency or EPA. It determines how pesticides can be used safely, based on their particular intrinsic properties, and by restrictions on how and when they can be used.

EPA Risk Assessments

Before any new pesticidal product can be sold in the United States, an extensive list of toxicological tests must be performed and reported to the EPA. The company that makes or which will sell the product is responsible for the cost of this testing, but most of the work is performed in contract labs that are closely audited by EPA. The tests evaluate many different facets of potential toxicity for human and environmental health, both in terms of short-term effects (acute toxicity via consumption, by skin exposure, by inhalation exposure…) and long-term effects on development, organ health, reproduction, and potential carcinogenicity. In addition, a great deal of data has to be generated to show what happens to the chemical over time on the food, and in the environment in terms of its persistence, movement, and breakdown into innocuous ingredients. It costs on the order of $286,000,000 and can take more than 10 years to generate all of this required data. EPA then uses these data to conduct an extensive “risk assessment.” Based on that assessment, EPA develops “label requirements” specifying how, on which plants, when, and how much of the pesticide can be used. These risk assessments cover issues of worker safety, environmental impact and also what sort of residues might be left by the time the crop is harvested, and any potential risk to human health.
Some safe, delicious apples ready for harvest in western Washington this summer

Pesticide Tolerances (or MRLs)

With regard to pesticide residues at harvest, EPA designs the label requirements to make sure that any residues still present when the food gets to the consumer are below what is called a “tolerance.” (Outside the US this is called an MRL or maximum residue limit). The tolerance is set to insure that there is a substantial margin of safety (typically 100-fold) between the allowed residue and any level to establish reasonable certainty of no harm to humans. EPA then sets limits on how much of the pesticide can be applied and how close to when the crop is going to be harvested so that the tolerance is unlikely to be exceeded when farmers use the product.
These tolerances are very conservative limits and represent such small amounts that they can be difficult to envision. For instance, a tolerance might be five (5) parts per million. That can be visualized as to two drops of water in a five (5) gallon carboy. Some tolerances are set as low as one part per billion (e.g. one drop in 528 carboys). In summary, tolerances are extremely small levels of pesticide residue, set as a conservative standard for human safety, and customized to the specific properties of the each chemical.


In order to be allowed to apply pesticides, farmers have to be trained and certified about how to comply with the chemical-specific label requirements. They have to maintain that training through on-going classes.

Is the System Working?

Every year, as part of a USDA effort called the Pesticide Data Program (PDP), thousands of food samples are randomly gathered from normal food channels and consumer markets. The samples are taken to labs where each sample is screened for the presence of hundreds of different chemical residues. The data that the USDA generates is transparently published both in raw and summarized form. Year after year, what the data show is that the system is working! The vast majority of samples have either no detectable residues or residues that are below the assigned tolerances – mostly far below. The fact that a small residue can be detected does not mean it is of concern. Modern analytical chemists have the ability to detect chemicals at very low levels. The reason that the numbers below tolerance are still published is not that they are of concern, but rather as transparent documentation that these products should be of little concern to consumers and regulators.  Several governmental agencies evaluate this information each year and confirm that consumers can confidently enjoy their food supply without concern about pesticide residues. The results were just released for 2015 and again document how well the system is working.  The FDA also has a residue testing program from which it concludes, "Results in these reports continue to demonstrate that levels of pesticide residues in the U.S. food supply are well below established safety standards."  California does its own residue testing and concludes, "California tests show low or no pesticide levels in many fruits and vegetables." Similar residue testing is conducted in Canada and the EU with equally encouraging results.  With this overwhelming body of evidence, how can the fear of residues persist?

What About the “Dirty Dozen List?”

Unfortunately, each year there is an organization called the Environmental Working Group (EWG) that takes the USDA PDP data and grossly misuses it to create a “Dirty Dozen List.” Instead of looking at how detections relate to carefully developed tolerances, EWG essentially treats all detections as significant – an approach that has been completely rejected by independent experts in the field of toxicology. EWG then recommends that certain crops be sought out as organic. Similarly misguided recommendations to purchase organic are published Consumer Reports. This makes no sense, since organic is not a safety certification. In fact, organic crops often have the same sort of low-level, detectable residues of pesticides as conventional (example data from the US and Canada). This point is conveniently ignored by these organizations.
In conclusion, we have a system in the US that both enables farmers to control pests and which protects consumers so that they can enjoy healthy foods without worrying about pesticide residues.

You are welcome to comment here and/or to email me at

Friday, October 21, 2016

Could The Humble Potato Change Your Image of GMOs?

Hash browns cooking - regular potatoes on the left and the new "White Russet" biotech potatoes on the right
Last week I got my first chance to cook with a "GMO" Potato.  I made one of my favorite breakfast dishes - hash browns!  I was excited to try that with these new potatoes because they have been modified to turn off the gene for the enzyme that makes them turn brown when cut (polyphenol oxidase), or in this case grated.  With regular potatoes, even if you work quickly, the grated potatoes begin to darken before you can get them into the pan.  I've gotten around that by grating them directly into the hot oil, but that is far from ideal in terms of safety.  With these new potatoes I had plenty of time to grate them and shape them.  They turned out not only looking far better, but also came out crispier and better tasting.  It is going to be difficult to put up

These potatoes have been approved for sale and are in many stores, but are not yet in stores where I live.  Colleagues at Simplot Biosciences were kind enough to mail me a bag.  I also posted a video about using this excellent new product.  There is a next generation of potatoes going through the USDA deregulation process.  In addition to the traits that reduce food waste (non-browning/bruising, low sugars in storage) and enhance food safety (reduced acrylamide production during frying), the latest potatoes also have a gene from wild potatoes that makes them resistant to a disease called late blight.  That is what caused the Irish Potato Famine in the 19th century and an issue for potato growing to this day.  The following is the comment I submitted to the USDA in support of deregulation:

(Submitted to USDA on 10/11/16 -

I am writing to support the deregulation of the X17 and Y9 potato lines which involve the same modifications as in previously deregulated lines.  Potatoes are a difficult crop to breed because they only rarely make seed and are polyploid.  While new lines are being developed, there is a substantial advantage of being able to modify older varieties that have proven field performance and desirable characteristics for cooking.  In this case the modified lines are Ranger Russet and Atlantic which are both important commercial varieties.

As with earlier lines, the RNAi gene silencing mechanism has been used to reduce the potential for acrylamide formation during cooking, reduce sugar production during storage which lowers quality, and reducing bruising and browning.  Together the last two traits will help to reduce food waste.  I believe that consumers will also find these potatoes to be quite desirable.

This week I had the chance to cook some of the Russet Burbank cultivar with this non-browning/bruising trait.  I like to make hash browns with fresh potatoes but because of the browning issue I have to grate the potatoes directly into the hot oil.  With these modified potatoes I was able to grate the potatoes and form them into servings prior to frying.  The non-modified potato I used for comparison was definitely inferior in terms of appearance and taste (I've included a picture of the hashbrowns - the upper one is with a standard potato and the lower one is with the down-regulation of the polyphenol oxidase gene.  I will certainly be looking forward to seeing more of these potatoes in commercial channels.

Top hashbrown from a standard Russet Burbank, lower from a White Russet, modified version.

Some critics have implied that the RNAi gene silencing mechanism could have unintended effects.  I believe that this discussion developed by Food Standards Australia New Zealand does an excellent job of debunking the paper by Heinemann et al which is often cited in this context.  Small double stranded RNAs are abundant in the food supply and this mechanism of gene regulation is widespread among eukaryotes.

As a plant pathologist I am particularly excited about one of the traits included in these new potato lines - resistance to the late blight fungus, Phytopthora infestans.  Not only did that disease cause the Irish Potato Famine in the 1800s, it represents a major management burden for potato growers around the world today.  To be able to include plant resistance in an integrated control program will be extremely helpful for potato growers.  The gene, VNT1, comes from wild potatoes native to South America.  To move that gene through conventional breeding would be slow and it would be very difficult to get back to the horticultural and culinary characteristics of desirable potatoes like Ranger Russet or Atlantic. This is an extremely logical application of modern biotechnology and one that would make a great deal of sense for other crops like grapes or coffee which also have pools of genetic diversity which are hard to utilize using conventional or even marker-assisted breeding.

To conclude it makes perfect sense to deregulate this crop as it presents no plant pest risk and substantial societal benefit in terms of food waste reduction and disease management.

Tuesday, October 4, 2016

A Day Of Accidental Ag Tourism

(This post originally appeared on Better Food Stories 10/3/16)

A few weeks ago I flew to Pasco, Washington and then drove up to Yakima. Eastern Washington is a very dry region, but it has several major rivers and the Columbia Basin Reclamation Project that allow for a flourishing and diverse agricultural industry. My progress was slowed by an irresistible urge to continually exit the main highway to take pictures of these carefully tended crops and to see some of the on-going innovation in planting systems.

A classical, widely spaced orchard

Tree fruits like apples, pears and cherries have long been important to this region. It was fascinating so see some of the innovation used to grow these crops. The image above is from a more classic orchard where large trees are grown with fairly wide spacing between trees and with large swaths between the rows. The next image shows a newer style orchard, in which trees are planted at high density along the row (every 18” or so), and supported by a trellis.
A newer, high-density, trellised orchard
This system gets the trees into full bearing within 2-3 years and can be harvested without the use of ladders (a worker safety and efficiency advantage). The space between the rows is also narrower requiring smaller equipment in terms of tractors, sprayers etc. Note that weeds are controlled in the row with herbicides for water efficiency, and the “middles” support a diverse “cover crop” which stabilizes and feeds the soil.
An alternative "V"shaped trellis system for apples
In the photo above we see a different trellising strategy. In this case, the high density trees are trained in a “V” shape with the goal of even more efficiently capturing the sunlight. Driving further down the road I saw something unusual in the distance and decided to investigate.
An interesting, covered orchard in the distance
It turned out to be another high-density, trellised apple orchard, but in this case it was being grown under a shade cloth to filter the light. This would reduce the chance of fruit getting a “sunburn”, and as you can see, this orchard had an abundant crop of picture-perfect fruit nearing maturity.

High density trellis under shade cloth


Hops, a highly aromatic plant, have been grown in this region since the 1870s, but even more so of late to meet demand for the booming craft beer industry. Hops are a vine which is trained on very tall (20’ or more) trellises. It is quite impressive to see! From the side of the field (below) it is a giant green wall.
One of the many "hop yards" in Washington serving the craft beer boom
Hops grown on trellises with telephone pole sized supports


Washington state is home to a flourishing grape industry with many excellent offerings for wine aficionados. It has also been a long-term source of juice grapes, which is what you see in the vineyard below. Note again the clean vine-row and the cover crop in the “middles.” This is the best way to use water efficiently, build soil quality, and prevent erosion on these hilly locations.
Eastern Washington is also home to many other crops. I’ll just throw in two more examples of a sweet corn field and an alfalfa field.
Sweet Corn 

The next day I had the privilege to spend time with a number of representatives of the grower organizations and others that support these Washington farmers. The meeting was organized by the Washington Friends of Farms and Forests, which is a grass roots alliance of those who grow the crops or tend the timberlands. I’ll be working with many of these folks for the next few months documenting some of their challenges and strategies tending these diverse plant species for the benefit of the broader society. As always, it was great to see real farming in action!

Monday, October 3, 2016

Why Wheat Is Like Wine

Wheat harvest on the Palouse in Idaho
(This post was originally on the Better Food Stories blog 9/26/16)

There is a term in the wine grape industry called “terrior” which celebrates the fact that fruit quality for wine making is greatly influenced by cultivar, climate and soil type.  Year-to-year differences in weather further influence the quality of specific “vintages.”  Wheat may be a humbler crop, but it is like wine in the sense that there are different classes of wheat for different end-use products and there are different regions where each type excels based on climate (wheat can be hard or soft, spring or winter, red or white, and there is a separate type called “durum” for pasta).  There are even year-to-year differences in quality.  For instance, to make an artisan bread, it is best to use flour from hard red spring wheat, that comes from the northern plains (North Dakota, Minnesota) or from the prairie provinces of Canada (e.g. Alberta and Saskatchewan).  For Asian noodles one wants a soft white winter wheat from the Pacific Northwest.  For crackers a soft red winter wheat is best from a place like Southern Illinois or Kentucky.  For pasta, a distinct type of wheat called durum is used and this is grown in Arizona and in the northern plains.

There are several important measures of wheat quality that reflect important properties of the dough, like strength and elasticity. These properties drive features, like how well the dough will rise and balance of different classes of starch, which influence the texture of baked products.  A yearly report on U.S. hard red spring wheat examines eight categories of “grading” data and eleven measure of “kernel quality.”  53% of U.S. wheat and 60% of Canadian wheat are exported around the world and purchased by customers looking for specific qualities (based on FAOStats data 2011-13). Europe is a major producer of wheat and has much higher wheat yields compared to the lower rainfall production areas in North America, but European countries still import a great deal of wheat for high quality bread and pasta and use much of their domestic production for animal feed.

As with all crops, wheat is attacked by various pests. Unlike grapes, it is possible to deal with some of the pests by breeding resistant varieties of wheat (winemakers are reluctant to accept new grape varieties preferring the traditional favorites that have been in use for hundreds of years).  A key advance in the “Green Revolution” of the 1960s was developing resistance to a particularly damaging fungal disease called “Stem Rust.”  That resistance held up for decades, but in 1999 a strain of the fungus overcame the trait, and since then wheat breeders worldwide have worked to breed a new resistance gene into all the different genetic backgrounds for the diverse wheats grown around the world.

In wet climates, wheat can be infected by many different fungal pathogens and commercial production requires the use of several protective fungicide treatments, starting with seed treatments and spaced throughout the growing season.  In drier North America, diseases are not as problematic, but do sometimes require treatments to preserve yield and quality.  If it rains during the time when the wheat is flowering, a fungus called Fusarium can infect the crop and wheat has proven to be very difficult to breed for resistance. A well timed fungicide spray can help against this disease, but that is not always possible. This particular fungus can produce a mycotoxin chemical in infected wheat kernels called Deoxynivalenol or DON.  It is also called “vomitoxin” because of the effect it has on animals that consume contaminated grain. In our food system, the consumer is well protected from exposure to such toxins, thanks to the care and expense taken on by farmers.
The global wheat industry is really made up of many distinct sub-crops, but as a whole, wheat production has been making steady progress in keeping up with growing global demand with only minimal expansion in planted areas (see graph below).  Some of that progress has been made by diminishing pest damage through a combination of breeding and crop protection agents like fungicides.  Also, a great deal of modern wheat production is in “no-till” systems where weeds are controlled with herbicides instead of by mechanical tillage.  This system greatly reduces soil erosion, lowers fuel use and leads to improved soil health and carbon sequestration.
The green part of each par shows the proportion of the increased production achieved through higher yield rather than additional planting area
So the next time that you enjoy a wheat-based product, think about the effort and risk that a wheat farmer faced, not only to produce the grain, but to produce it with the positive qualities needed and with the absence of issues like DON toxin.