Friday, July 24, 2009

Killer Carrots Invade Local Town!

One of our local newspapers had an article today warning of encroaching populations of Giant Hogweed. The sap of this plant contains a chemical that, when illuminated by the sun or other sources of UV light, causes very serious inflammation, blistering and scarring of the skin. Any contact with this (up to 20 foot-tall!) plant is dangerous and even very slight eye exposure can result in blindness.

Hogweeds are a member of the carrot family, the Apiaceae. This family was formerly known as the "Umbelliferae," referring to their clusters of flowers, which arise from a common point, like an upside-down umbrella. This is one of those plant families that has taken spectacular advantage of its potential arsenal of chemical weapons. The Apiaceae contains both choice, highly-aromatic and flavorful crops, and dangerous poisonous weeds. Common Apiaceous crops include carrots, parsley, parsnips, celery, dill, caraway, fennel, coriander/cilantro and cumin. One of the most famous poisonous species is hemlock, an ingredient in Socrates' last cocktail (this is different than the tree). Often, very small morphological differences distinguish edible domesticated, edible wild, and poisonous wild species in this family.

My rural jogging route has been offering me some good opportunities to brush up on my knowledge of East Coast flora. So far, the main Apiaceous flowers in my local fields seem to be the edible wild carrot (aka Queen Anne's Lace) and wild parsnip. I'll post some pictures soon.

Tuesday, July 21, 2009

No Such Thing as a "Superfood"

Goji (wolfberry) is one of the most recent fruits to be hyped as a "superfood," alongside acai, pomegranate, cranberry, blueberry and many others. These foods are supposedly packed with beneficial chemicals including antioxidants, vitamins, minerals, fiber and other so called "phytochemicals," an incredibly irritating neologism of the words "plant" and "chemical."

This trend annoys me not only because there is often really lousy science backing up the claims that individual chemicals (out of tens of thousands of unknowns) in these foods are beneficial for human health but also that it goads people into taking concentrated pills and extracts that supposedly isolate and concentrate what's best about our food. This magical reductionism seems uniquely American to me and completely overestimates out understanding of exactly what in these foods is good for us.

Similarly, I've consistently heard that a lot of nutrition scientists and government regulatory agencies have stuck with outdated nutrition assays (e.g. antioxidant assays) because 1) they already know how to do them and 2) they want to be able to compare new results to old results.

I saw a great presentation by the Cornell food scientist Rui Hai Liu a few months ago where he described his new "cellular antioxidant activity" assay. He described how his new assay measured the antioxidant activity of fruit chemicals much more accurately than older methods by considering the ways that these chemicals actually get into your cells and protect you from normal oxidative stresses that contribute to diseases such as cancer. One of the most effective antioxidant extracts turned out to be apple juice! Conventional wisdom never would have guessed this. It really goes to show how little we actually understand what's in our food and how it affects our health.

I ordinarily wish that Michael Pollan would keep his poorly-informed opinions to himself, but I agree with him when he tells people to stop stressing out so much about optimizing their nutrition and just eat a diverse diet, mostly veggies.

Monday, July 20, 2009

Down with the Union of Concerned "Scientists!"

I always assumed that the Union of Concerned Scientists, a special interest group, spoke for my interests as a scientist. They definitely do not.

Science had a brief history of UCS a few months ago. This group originally focused on what they considered to be an "appropriate" level of regulation for nuclear power. Since, they appear to have consistently leaned less towards the scientific viewpoint, than the environmentalist one (in the worst, religious fanatic sense of the word). I was incensed to discover on their website that they opposed genetic engineering for the same silly reasons offered elsewhere.

Well, they're at it again. They recently released the report: Failure to Yield: Evaluating the Performance of Genetically Modified Crops. According to a story in Nature Biotechnology, contacted public-sector crop scientists have been "uniformly critical" of this report, for lots of good reasons described therein.

I'll keep it simple. They suggest that Bt crops don't have higher yield than their conventional versions. (Bt is a natural bacterial toxin that kills insects and is often used in organic agriculture. Bt-GMO crops have been genetically engineered to produce the protein themselves instead of relying on the farmer to spray it.)

This is a complete strawman argument. The whole point of having the crop make its own Bt is that it saves the farmer money, time, pesticide applications and tractor fuel. This is good for the farmer and the environment, whether yields are higher than with conventional crops or not.  And let's not forget that not all pesticides are created equal.  The active ingredient in Roundup (glyphosate) is less dangerous to humans than either caffeine or aspirin.  Additionally, GM glyphosate and GM Bt resistance have largely supplanted the use of infamously dangerous old-fashioned pesticides like atrazine and organophosphates.  Whatever threats you may hypothesize to the former two, the latter two have left a real record of human death and ecological destruction.

Farmer's aren't stupid. If Bt crops didn't work, they wouldn't have been adopted at such a phenomenal rate.

Saturday, July 18, 2009

Replicating Terroir

Terroir is a collective term for all the particulars of a locality (climate, soils, topography) that shape the quality and flavor of ag products such as wine grapes and coffee beans. Terroir is the reason why so much time is spent discussing why certain regions of the globe are critical for the highest quality production of prized varietals such as Cabernet Sauvignon and Pinot Noir.

It's long been my impression that fruits tend to produce better flavors when the plants have been beat up a bit. A lot of the chemicals that we perceive as flavor and scent are involved in plant defense from pathogens, pests and harsh weather. Drought in particular has long been known to be critical for the production of quality wine grapes since it concentrates sugars and other chemicals in the berries.

I came across a paper on this topic the other day. The authors followed gene expression and levels of antioxidant, pigmentation, flavor and scent chemicals over time in Cab and Chardonnay grapes that either were, or were not, exposed to drought conditions. Not surprisingly, they found that drought increased the amount of these chemicals in wine grapes. Their results also suggested that much of this was mediated by the plant hormone abscisic acid (ABA).

I'm not sure what I think of this kind of reductive food science. It's fascinating to be able to understand our basic experiences in such detail, but I'm not sure what practical benefit it offers. Most of these types of studies seem to just lead to nutritionists latching on to a few chemicals out of thousands in something as complex as a grape, declaring them 'healthy,' and leading people to take vitamins and supplements that supposedly recreate the best parts of a varied diet with large doses of a few chemicals.

On the other hand, perhaps a more full understanding of how plants regulate the production of these important suites of chemicals will lead to the breeding and engineering of plant varieties (or plant hormone sprays) that are more obliging in the production of high-quality, flavorful fruit under a broader range of conditions.

Wednesday, July 15, 2009

100% Adulterated Honey

So I heard on the radio yesterday that Florida passed a law that only pure honey can be now be labeled as "honey." Apparently, it's common for honey to be cut with sugar and other ingredients. Who would have thought?

The Wegman's honey in my kitchen cabinet just says "honey." I guess that means it could be full of sugar?

As a non-sequitur, I'm reminded of watching the pretty comical effort of a couple of Davis J St. Co-op inhabitants work to pour a bucket of homegrown honey into mason jars a few years ago. A lot of the honey (full of sticks and bees) proceeded to ooze all over the outside of the jars and onto the kitchen floor, as the two ambitious DIYers tried to box out the house golden retriever. That certainly wasn't pure honey either, but at least they knew what was in it.

Tuesday, July 14, 2009

Monsanto's back in the wheat business

Monsanto has acquired WestBred LLC, a company specializing in wheat germplasm. Currently, the big seed companies specialize almost entirely in corn and soybeans, largely thanks to demand driven by subsidies. Wheat, one of the world's most important crops, was historically maintained and improved almost exclusively by public sector plant breeders.

Wheat was originally neglected by the private seed industry due to its lack of heterosis. Heterosis, or hybrid vigor, is the poorly understood process whereby the hybrid offspring off two different varieties of a crop is stronger and more high-yielding than its parents. This effect does not extend to the 3rd generation. This effect is so strong that farmers several decades ago began purchasing hybrid seed instead of saving their own as the increased yield was worth more money than the cost of seed plus any risk of dependence on the seed salesman. This didn't happen with wheat though. Without hybrid vigor, no company could quickly produce a new product valuable enough for a farmer to buy. Besides, prior to current patent laws, there was nothing to stop a farmer from buying expensively-bred seed and illegally propagating it himself.

Maize DOES benefit from heterosis, and it was the new business of selling hybrid maize seed that launched the private seed industry and the private plant breeder. The private seed industry made incredible progress improving maize varieties and farmers have eagerly bought the newest, hottest seeds each year ever since.

Sunday, July 12, 2009

Deep Fried Daylilies

The meadows and pastures along my running route are full of edible plants. Today I start working my way through them.

Here's a view of the drainage ditch that runs along this part of the road, filled with daylilies, cattails and elderberries.

There are a number of ways that people prepare daylilies, but simply frying them was the most appealing of the easy recipes. Here's the one I used.

Raw, the flowers tasted very weakly of lettuce or snap pea greens. Fried, they tasted like salt and fried batter. The petals left a thin, not unpleasantly chewy center. In the future, I'd consider including them as an edible garnish (the way most of the recipes seem to), but if I want the novelty of a fried flower, I'll stick with squash.

Saturday, July 11, 2009

Central NY Mushrooms

Well, one good thing about all the rain we've been having is that I keep seeing mushrooms pop up under the conifers outside my window.

A big family of fly agarics lives there. I quickly keyed this one out to, probably, Amanita muscaria var. formosa. This genus of mushrooms is responsible for 90% of mushroom ingestion fatalities, though some species are perfectly edible. Some say that the only cure for eating the most poisonous members is a prompt liver transplant. A. muscaria, depending on the genetics of the specific mushroom clone, and the physiology of the consumer, may be poisonous and/or hallucinogenic.

There also were a large number of little brown jobs that appeared to belong to the Cantharellaceae, a family that includes many outstanding edibles, including chanterelles. I haven't studied mushroom taxonomy enough to consider eating wild ones so I didn't bother going further in trying to identify them.

Both these mushrooms are mycorrhizal, meaning that their extensive, underground mycelia are fused with the roots of certain species of trees and other plants. In this mutualistic relationship, the fungus generally gives its plant host greater access to water and mineral nutrients in exchange for carbohydrates.

Why the Public Trusts Climate Science, not GMO Science

I think Noel Kingsbury is right on target in this SEED article from last month.

Genetic engineering came onto the scene at a time when both the public had largely lost faith in science and the U.S. public funding of crop improvement was essentially replaced with private funding by international monoliths, such as Monsanto*. The consciousness of the public has completely tangled the concept of genetic engineering (which isn't categorically different than other breeding techniques) with fears of the archetypal monopolistic, unethical multinational corporation. I think the opposition to industrial agriculture also comes from the fear of what happens to the little guy/human soul when new technologies and the economic machine eliminates a former way of life.

Let's try not to get our science mixed up with our philosophy.

*In Monsanto's defense, they've authorized free use of any of their patents to non-profits working to ameliorate poverty in Africa. Wouldn't be great if the pharmaceutical companies did the same and stopped prohibiting African countries from manufacturing AIDS generics?

Beating Suburbs into CSA Shares

One in six cities is suffering from depopulation largely due to the shifting tides of economic opportunity and emigration to the outer suburbs. Formerly vibrant working and middle-class neighborhoods begin to decay as they are slowly abandoned, land prices and local taxes plummet and urban blight results when the remaining inhabitants are unwilling or unable to maintain a constructive and supportive community.

Forum had an exciting program this week discussing the efforts of Flint, Michigan to downsize to fit their post-industrial economy. Briefly, the Genesee County Land Bank is buying up vacant, abandoned lots (in addition to the properties of locals who want to move out), cleaning them up and attempting to create spaces that will increase local quality of life and property values (e.g. parks). They're providing free use of plots to inhabitants who want to improve their neighborhoods (e.g. by creating community gardens) and they're offering plots for sale at deep discounts to citizens with constructive ideas. They specifically mentioned how they hoped to attract artists and urban farmers to transform cheap, unappealing land back into space that people would want to live in.

I hate watching progressive rings of poorly-designed and cheaply-built suburbs and exurbs chew out into the good agricultural land and wilderness surrounding our cities. As a proponent of New Urbanism and Suburban infill, I LOVE that this local community is making efforts to revitalize and repopulate it's downtown and inner suburbs.

Why don't we switch our agricultural subsidies to ripping up urban driveways and alleys and hauling away housing debris so that urban farmers can grow high-value fruits and vegetables for local consumption?

Friday, July 10, 2009

First Harvest

My garden's been pretty slow this year with all the rain and 40F nights we've been having, but the lettuce mix is finally big/crowded enough to start thinning it out. Hopefully a sunny weekend will bring about a growth spurt all around.

THIS is why Organic Ag is Bad for the Environment

On my way to work this morning I heard a brief story on NPR about the impact of the current late blight epidemic on local farmers.

One organic farmer explained how he would suffer a total loss this year without spraying some sort of fungicide on his crops. Unfortunately, to keep his organic certification, his best option was to spray copper, a naturally occurring chemical
(inset: copper strip-mine in NM).

He said he would usually only have to spray copper on his land in October but because of the intensity of the current epidemic, he has been spraying it every five days.

Picture what impact it has on his local ecosystem to have that amount of heavy metal pollution introduced to it. It would be more sustainable to use a modern synthetic fungicide that has very limited non-target toxicity and rapidly decomposes when exposed to sun and water.

Copper is a "biocide," meaning it hurts all organisms, and it lasts forever...

Wednesday, July 8, 2009

European Union approves GM corn

The European Food Safety Authority has declared that Monsanto's insect-resistant MON810 maize variety is not significantly different than the non-transgenic version of this crop and poses no safety concerns. *

This decisions brings the EU directly into conflict with the multiple member states that fiercely oppose the planting of any transgenic crops.

Hopefully cool heads and logical arguments will carry the day. There's no reason to think any of the current generation of genetically engineered crops are a threat to human health or the environment.

*Internationals always refer to corn as "maize" since many countries use the word "corn" for other grains such as wheat and sorghum.

Monday, July 6, 2009

The End of Overeating

David Kessler, former head of the FDA, was on Forum today discussing his new book "The End of Overeating: Taking Control of the Insatiable American Appetite."

He argued that Americans are fat because the sugars, fats and salt that fill processed food inhibit natural feelings of satiety by overwhelming the brain's reward system. Coincidentally, I came across a Science paper this afternoon on a similar topic. This paper pointed out that many of the chemicals responsible for the scents and tastes of fruits are actually fragments of larger chemicals, many of which are known to be important for human nutrition. They hypothesized that these chemicals were a way for plants to communicate with animals - "hey! eat me! (and disperse my seeds)." In their final sentences they muse if the combination of natural and artificial flavors in nutrient-poor processed food tricks the brain into favoring these poor food sources.

Outbreak of Irish Potato Famine pathogen

It was recently discovered that infected tomato plants were sold in big box store garden centers throughout the Northeast. The plants are infected with the causal agent of late blight, Phytophthora infestans, a fungus-like brown alga that's closely related to diatoms and kelp. Tomatoes, potatoes and their relatives are extremely susceptible to this pathogen, which was responsible for the Irish Potato Famine. I saw this pathogen decimate potato fields when I interned at a fungicide company after college. The plants just melted into rotting, black piles.

If you have infected plants in your garden you should destroy them and consider safely applying a commercial fungicide. (Don't ever compost sick plants (or weeds), since their spores will often survive or multiple). The guys at our experimental farm have already started spraying our fields, which is a real shame. They usually don't have to spray until late in the summer, but we risk losing a year's worth of data without it. Our cool, wet, cloudy summers in Central New York are perfect for this disease.

Sunday, July 5, 2009

Deck Gardening

Someday I'll have a plot of land big enough for fruit trees and maize. In the meantime, I'm making do with my second story, western exposure deck.

This season I have two heirloom tomatoes (Hank and Black Plum), a sunberry, a ground cherry, green beans, snap peas, carrots and a salad mix. I'm also making an attempt to compost in the three black pots (an admitted long-shot). The minimum recommended size for compost piles is generally 3' x 3' x 3' but I'm gonna take a shot anyway. Maybe if I partially cover the tub in plastic it'll retain some heat during the winter...

I direct seeded the cold-weather species (carrots, peas, salad mix) at the beginning of June, following local recommendations. I started the warm weather fruits and beans in the greenhouse and transplanted them a few weeks later.

Shortly afterward I noticed that many of them were beginning to look pretty yellow/pale. Nitrogen deficiency was the first disorder to come to mind. Iron deficiency was also possible, but less likely since my plants did not retain green veins. Since plants are able to relocate some nutrients/micronutrients within their bodies (but not others), it can be an important clue if only the new leaves show symptoms, or only the old leaves. Overall, nitrogen deficiency is a common disorder and produces symptoms consistent with those observed.

Despite this, I was slow to believe nitrogen deficiency was the culprit since I had JUST planted the seedlings in new soil and because both legume species (pea and bean) are able to obtain nitrogen from the air through symbiotic rhizobia bacteria, which live in their roots. We had received a tremendous amount of rain the previous week, so it was also possible that the roots were not functioning well due to flood-induced oxygen deficiency. To test these hypothesis, I poked lots of holes in the soil in 2 containers to aerate them, and shredded clover roots (another legume growing in our lawn) into 2 other containers to inoculate them with the local microbes.

Unfortunately, the plants began to turn white over the next two days so I had to end my experiment and take more drastic action - by buying cheater-fertilizer. With plenty of nitrogen, the garden greened right up.

Saturday, July 4, 2009

Why supermarket tomatoes have no taste

It's an old cliche that 'nothing tastes like a garden-fresh tomato.' The ones you find at the supermarket often seem to be hard, watery and tasteless.

The reasons can be summed up in two words: Industrial Agriculture.

Prior to the 1940s, when the U.S. was still a predominantly rural country, most people only ate food they and their neighbors could grow and store. If it didn't grow in your town or couldn't be kept canned, salted, dried or in a cool cellar, you rarely ate it. My great aunt once described how she and her siblings would often receive oranges as Christmas presents.

As the decades rolled by, Americans flooded into cities looking for opportunities, and flooded out into the suburbs with their new-found wealth. Much like today's organic and foodie enthusiasts, contemporary Americans were excited by the possibility of having a greater diversity of food for a greater proportion of the year. Truck farms sprang up in regions that benefited from mild climates and proximity to major urban centers. Huge quantities of fresh produce were produced in areas such as southern New Jersey (hence "The Garden State" and "Jersey tomatoes"), and shipped to nearby cities such as New York.

This huge demand for new and better varieties supported professional plant breeders who worked to increase the yields and stress tolerance of their favorite crops. Economies of scale rewarded growers who set up massive farms in warm climates with long growing seasons and shipped their product across the country as opposed to working locally with whatever resources were available. Plant breeders helped get more food to the people at an affordable price by focusing on producing varieties that could be harvested by machines and sit for long periods of time on trucks and grocery shelves before going bad. These new varieties were often less tasty than their ancestors, but they were available, inexpensive and an important source of healthy, diverse food for new urbanites.

Tomato is a particularly informative example. In the 1940s, a Cornell agricultural scientist discovered a natural mutation in his field tomatoes. One plant produced green fruit that refused to ripen. Over time it was discovered that this plant has a broken version of a gene that is a master regulator of ripening. A normal tomato plant has two good versions of this gene while a plant with two broken versions is ripening-inhibited (rin). A plant that has one good copy and one broken copy ripens very slowly and never quite becomes as flavorful as a normal tomato - but it can be shipped long distances and stored for long periods of time without rotting into ketchup. These hybrids represent a very large proportion of supermarket tomatoes.

Now that consumers are demanding higher quality in addition to availability, plant breeders and agronomists are working hard to create new varieties and growing practices that supply people with the best tasting and most nutritious foods they can at a reasonable price.

Attack of the Agircultural Pests

Just about all the plants are in the ground in my lab's 3 experimental farm plots. Hopefully the tiny seedlings will grow fast into strong adults before the hail and local critters take them out. We've had too much rain so far this summer but I'm optimistic we'll get a good harvest.

Last week my boss and labmates and I spent the day hammering in a ~1000 foot fence around our one plot that we especially need to keep animals out of. Previously, the black plastic mulch was covered in footprints and holes made by deer and some bird with big feet (crows?). We weren't happy to see large pieces completely torn away on the side of the field closest to the creek. We assumed this was the work of groundhogs but the farm guys told us it was actually snapping turtles! Maybe they tore it while basking?

At any rate a subsequent storm blew most of it down. The farm guys generously fixed it for us so now we just need to wait and hope for better weather.

Friday, July 3, 2009

Biotech-blue Roses

Blue roses may be the horticultural Holy Grail, but despite careers-worth of effort no plant breeder's been able to come closer than lavender. This is due to a fundamental quirk of rose biology that's now been "fixed" with genetic engineering.

Plant color is largely determined by three classes of pigment chemicals: chlorophylls (photosynthesizing greens), carotenoids (yellows, oranges and reds), and anthocyanins (red, purples and blues). Each one of these three classes contains many chemicals which differ slightly from each other in molecular structure, and therefore chemical properties (e.g. hue). Each of these unique chemicals is produced and modified by an array of enzymes. Ultimately, the color of a given plant tissue is determined by what combination of these enzymes are present.

The headwaters of the anthocyanin biosynthetic pathway begin when an enzyme (chalcone synthase) smooshes together two chemicals (coumaroyl CoA and malonyl CoA) to create a third chemical (a chalcone). Another enzyme (chalcone isomerase) converts this chemical into naringenin (which contributes to the bitter taste of some citrus fruits). As more and more enzymes begin to work, this pathway quickly branches into many different streams, leading to many chemicals that play important roles in plant food flavor and nutrition.

Anthocyanidins pool at the end of a few of these streams with names that are often indicative of their color and origin of discovery: peonidin, cyanidin and delphinidin. The stream that leads to delphinidin (a blue chemical) requires several specific enzymes, including F3'5'H (flavonoid 3'5'-hydroxylase), which smooshes a molecule of water onto a specific position on the pigment molecule.

Since no rose varieties contain a functional copy of this enzyme (F3'5'H), no amount of clever plant breeding has been successful in creating a blue rose.

An Australian biotech company, Florigene, has succeeded in this long-sought goal by using genetic engineering techniques to move a working copy of this enzyme from a pansy into a rose.

Let me know if you see this recently-licensed variety at your local garden center!

Tanaka and Ohmiya. 2008. Seeing is believing: engineering anthocyanin and carotenoidbiosynthetic pathways. Current Opinion in Biotechnology. 19:190.


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