Veggie libel laws…

In reading Food Inc.: A Participant Guide: How Industrial Food Is Making Us Sicker, Fatter, and Poorer—And What You Can Do About It (the companion book to the film Food, Inc.), I came across the idea of “food disparagement laws“.  What’s that?  Well, apparently in 13 states in the US, it’s illegal to speak badly of food.

You may recall that in 1996 Oprah Winfrey was sued for statements she made about not beef in the context of BSE (“mad cow disease”).  Apparently she was sued under Texas’ food disparagement law.  From what I’ve read, Texas’ law is actually the least badly written of the set, but all of the laws have been criticised on the basis of their potential chilling effect – since you can be sued if you “libel” food, people will be unlikely to speak out about real concerns about the food supply.  Makes you wonder whether you need to have your lectures screened by a lawyer, at least when you’re talking about food…

Seeking sustainability in Amazonian palm production

Mauritia flexuosa, commonly known as the Moriche palm, aguaje, burití (and a variety of other names) is a large palm which is native to tropical South America and Trinidad. It grows in permanently or temporarily flooded forests, and often forms monodominant stands.  In parts of South America these stands cover thousands of hectares at densities which can exceed 300 trees per hectare.  Moriche palms are important as a source of “food, fiber, oil, medicinals, materials for construction and fishing equipment, and fallen stems serve as a substrate for raising of edible larvae of the palm beetle (suri, Rhynchophorus palmarum)”¹

Palm fruits are important food sources both for humans and wildlife.  The outer surface of the Moriche fruit is reddish-brown and scaly.  Beneath this is a thin layer of yellowish pulp which covers a large seed.  This pulp is used in Peru to make ice cream, popsicles and cold drinks.  Consumption in Iquitos ranges from 22-150 tonnes/month.  The harvest and sale of the fruit is an important source of income for rural people in the Peruvian Amazon.¹

The idea of a non-timber product from the rainforest with a well-established market…it seems too good to be true.  And in a sense, it is.  While it would seem to be the perfect tool for forest conservation, demand for aguaje has led to the degradation or destruction of extensive areas of Moriche swamps.  You see, the normal way to harvest the fruit is to cut down the tree.  Aguaje production around Iquitos, Peru, is estimated to lead to the destruction of at least 24,000 trees annually.¹ It takes 7-8 years for an individual to reach maturity, so the rate of replacement of cut trees is pretty slow.  Add to that the fact that the most productive trees are cut (it takes the same effort to cut down a tree with a large fruit crop as it does a tree with few fruit) and the end result is pretty obvious.  Not only do aguaje collectors have to travel to more and more remote sites in order to harvest fruit, the trees left behind to re-seed the area are the ones that produce the least attractive crops.  In addition, moriche swamps are important food resources for wildlife.¹

The depletion of moriche stands is apparent to local people, especially those who earn income by harvesting the fruit.  In the interest of sustainable harvest, a climbing system was developed that made it possible to harvest fruit without destroying the tree.  Maya Manzi of Clark University and Oliver Coomes of McGill looked at the effect of the introduction of the climbing system to the village of Roca Fuerte in Peru.  Since 1999 Fuerte Roca has been located on the north bank of the Marañón River in the Peruvian Amazon.  Prior to that it was located on the south bank.  Relocation across the river allowed them to exploit new stands of Moriche palms.  In 1999 the stands had been nearby, but four years later it took almost three hours to reach productive stands.  Seeing this change, and being aware that a similar thing had happened when the village was located on the south bank, the villagers were willing to work with an NGO to try to find a way to sustainably harvest the palm fruit.  Purchase of the climbing system led to the designation of an extractive reserve where fruit could only be harvested by climbing, not by cutting.

Manzi and Coomes looked at the socioenomic characteristics of the villagers and tried to determine which factors made them more likely to adopt the new means of harvest.  Unsurprisingly, younger people were more likely to adopt the new technology, as were those who were more successful hunters.  Families with “fewer non-land assets” and less hunting experience were less likely to adopt the newer technology.

One constraint on the adoption of the new technology was the fact that the village had only been able to afford to purchase four sets of climbing gear.  Since climbing requires a fair amount of manual dexterity and strength, it’s probably harder for older people to learn.  (Now, granted, I’ve seen old men climb coconut trees, but they have probably been doing it all their lives.)  I would tend to assume that younger people would also be more likely to adopt new technology, but I have no idea whether my assumptions translate to rural Peru.

I found it interesting that hunting success correlated with a greater willingness to adopt the climbing techniques.  The authors explained this as follows:

Our second model reveals that participation in harvesting by climbing instead of felling tends to be higher among younger households and those with higher forest knowledge, as reflected by success in hunting large bodied animals (mainly ungulates). Hunters are well aware that large ungulates depend on the availability of aguaje palm fruit and that they play an important role in the regeneration of aguaje palm forests through seed dispersal. As such, hunters have a strong incentive to protect aguaje stands.

Other factors like having “fewer non-land assets” are interesting, but less well explained.  The paper also discusses factors related to the willingness of people to cultivate the palms – interesting stuff, perhaps for another time.

Photo credits: The first photograph, copyright Eurico Zimbres, is from Wikimedia Commons and is licensed under the Creative Commons Attribution 2.5 License.  The second photograph was related into the public domain by its creator Frank Krämer.

Manzi, M., O.T. Coomes (2008). Managing Amazonian palms for community use: A case of aguaje palm (Mauritia flexuosa) in Peru Forest Ecology and Management DOI: 10.1016/j.foreco.2008.09.038

Bugmeal?

While I have read some of the people at ScienceBlogs on a daily basis for months, I still have not plumbed the depths of what’s available in terms of good reading.  I recently came across Shifting Baselines, a good ecology/conservation biology blog written by Jennifer Jacquet, a doctoral student at the University of British Columbia, Josh Donlan, a conservation scientist at Cornell and Randy Olson, the creator of A Flock of Dodos.

In January, Jacquet discussed a study which looked at replacing fishmeal (which is used to feed chickens, pigs and fish) with “bugmeal”.  Working with striped bass, researchers at Mississippi State University found that the fish readily took the “bugmeal” and the final product was similar to fishmeal raised fish, but had a less “fishy” smell (which is considered a bonus by American consumers).  Today she presented some response to questions she asked Lou D’Abramo, the lead scientist on the Mississippi State project.

The first question really gets to the heart of the problem of our industrial food production system: what are the insects raised on? The answer – grain, probably corn.  Lovely.  Fortunately, D’Abramo seems to be aware of the problem with that, and discussed the idea of raising them on fish wastes.  He also talked about raising insects on waste products to alter their fatty acid profile – something that wouldn’t have have been the least bit surprising had I read that with my aquarist brain switched on…you read a lot about fatty acid profiles in the context of getting your Corydoras to breed.  (I should do a less good job of compartmentalisation.)

Finding a substitute for fish meal is a good thing.  Insects sound like a good substitute.  But our industrial system of agriculture just makes things like this awfully complicated – needlessly complicated.  Small farmers feeding fish on grubs or mealworms raised on locally generated waste sounds workable.  Industrial-scale “bugmeal” production, on the other hand, raises the usual problems of energy demands, transport, and waste production.  One step forward, but we’re on a conveyor belt running us backward…

Learning not to burn

As the dry season progresses in Trinidad, smoke becomes an ever-present feature.  While people blame “bush fires” on spontaneous combustion, most are either arson or agricultural fires.  While it always bothered me to see the landscape burn, it was the especially intense fire season of 1987 that really opened my eyes to the problem.

The Agricultural Fires Act, passed somewhere in the distant past, was an attempt to prevent burning.  The act made it a crime to plant annual crops on land that had burned.  I would be surprised if the act has ever been enforced; more to the point, while it may have been used for punishment a few times, it was designed to change behaviour.  And on that front, it was a colossal failure.

Fire has always been used to clear land for agriculture.  Where permanent cultivation replaces shifting cultivation, fire becomes less important as the frontier moves on.  But where land is farmed for a few years and then abandoned, fire is an essential tool.  This is especially true on poor tropical soils – not only is fire an efficient tool for clearing land and releasing nutrients from the vegetation, but the ash is also increases soil fertility by raising the pH and increased the nutrient holding capacity of the soil.  Fire is also useful for controlling pests and pathogens – in the tropics there is no winter to knock back pest and pathogen populations.

But there’s a cost to using fire.  The simplest one is the risk of escape – agricultural fires are a major ignition source for wildfires.  Fires kill beneficial soil organisms, they consume soil organic matter.  And smoke can have a major effect on health and quality of life.

The latest issue of New Agriculturist has an article on the work of a group called Sustainable Harvest International which is working with farmers in Central America to teach them alternatives to burning.  They are teaching the use of cover crops, integrated pest management, and erosion control techniques and something called bocashi as ways of reducing reliance of fire as an agricultural tool.  Bocashi is interesting

This highly effective and inexpensive natural fertiliser can be made from readily-available materials, including manure, coffee pulp, or rice hulls, together with yeast and molasses. These are then mixed with healthy soil. The yeast feeds on the molasses during a 15-day fermentation and decomposition process, aided by mixing manually twice-a-day. The bocashi mix is then added to crops, and yields either match or improve upon those obtained with chemical fertilisers – at a fraction of the cost.

They appear to be teaching the use of permanent fields as an alternative to shifting cultivation.  Back in the day when I thought of forest conservation as the most important issue, I would have supported permaculture over shifting cultivation without a second thought.  But permanent cultivation usually entails heavy chemical use, and leads to continuing losses of soil carbon, soil fertility and the general “health” of the soil.  It appears that this isn’t what is being done here – working with an eye to sustainability (rather than just forest conservation), this group appears to be getting it right.  An important factor is that it appears to be improving the quality of life for the people involved:

Don Cheyo, a graduate of SHI’s Honduras Program, says “We eat better and I live with the land – planting good food, building up the soil and planting trees. I have learned not to burn.”

It’s great to appeal to people’s better nature, but you’re more likely to make permanent changes if you also make their lives better.

Which brings me back to the Agricultural Fires Act in Trinidad and Tobago, passed in 1965.  The failure of the government to enforce this law has been a source of frustration to the conservation community in Trinidad, probably ever since it was passed.  Quite frankly though, it is and has always been a useless piece of legislation.  Granted, any law that isn’t enforced is useless, but it’s especially bad when it seeks to change established behaviour.  You can’t simply tell people “don’t burn” and expect them to stop, not when burning is an integral tool for them to earn their livelihood.  Although some people do set fires for the sheer joy of watching them burn, the people who set agricultural fires do so because it’s a tool for them to earn a living.  If you provide people with reasonable alternatives, you may be able to bring about change.  After you provide people with alternatives, you may want to add the option of the “stick” – legal penalties against the undesirable behaviour.  Laws like this only serve to convince people that government is out of touch, uninterested in them.  But then, in our post-colonial society, government has never been “of the people” – “home rule” and “independence” were merely the delegation of royal power to someone who was physically closer to you.  Neither the governed nor the governing ever really understood what “representative government” is supposed to mean.

H/T Jeremy, Agricultural Biodiversity Weblog

Yoghurt containers as mini-greenhouses

Willem van Cottem of Desertification has a very interesting post about the use of transparent containers as mini-greenhouses. You can use them to get seedlings started indoors in the Spring, or in arid environments (since it cuts down on water usage prior to transplantation). They are also useful for transporting the seedlings.

I would be a little concerned about hardening the seedlings – that they might not be able to handle the desiccation without significant die-back – but I suspect that he has taken that into account.

Bt cotton and the evolution of resistance

Over the last decade, genetically modified crops have become widespread in agriculture. One of the more successful of these are Bt crops – transgenic plants that express genes derived from Bacillus thuringensis. These genes allow the plants to produce toxins which specifically affect certain groups of insects. Since these plants do not need to be sprayed, and since the toxins are relatively specific, the environmental effects appear to be lower than conventional agriculture.

However, Bt toxins face the same problem that other pesticides face – the evolution of resistance in target insects. The selective pressure of a compound in your food that kills you (unless you have a resistance gene) is huge. The more widely a Bt crop is planted, the greater the selective pressure. And unlike pesticides, to which a pest is only exposed periodically, Bt toxins will (presumably) be produced by the plants on a continuous basis. Since lab studies had showed that pest species possessed genetic variation in their resistance to Bt toxins (including this 1998 EPA study), the question is more one of how quickly resistance would evolve, rather than if resistance would evolve.

One strategy to slow the evolution of resistance is to plant areas of non-Bt plants near to the fields of Bt crops. These would serve as refuges for populations of non-resistant insects. In principle it should work great – as long as the resistance genes are recessive. If you plant a large area of crops that are toxic to their pests, what happens is that most of the pest population will be wiped out. A few will have some resistance (after all, Bt toxins exist in nature – Bacillus thuringensis occurs in nature, and is likely to have interacted with the pest species in its evolutionary history). Since all the individuals lacking resistance genes would have been knocked out of the population, resistant individuals would mate with one-another. As a result, each subsequent generation should be more resistant than the previous. However, if you provide a refuge of non-Bt crops, most of the individuals in the next generation would come from that part of the population.

If resistance to Bt toxin is a recessive trait, an individual needs to inherit the gene from both parents in order to be resistant. If the population is only made up of those who survived exposure to the toxin, they will mate with one-another, and their offspring will inherit the trait. On the other hand, if the population is dominated by susceptible individuals (those that fed on the non-Bt crop) then the survivors’ genes will be diluted in a much larger population. On the other hand, if resistance is a dominant trait, providing a refuge won’t work. If the trait is dominant, it doesn’t matter who the survivors mate with – they will still be able to pass their resistance on to their offspring.

In an article published in Nature Biotechnology, Bruce Tabashnik and colleagues looked at the actual pattern of evolution of resistance to Bt toxin Cry1Ac in cotton over a 10-year period. They used studies conducted in Australia, China, Spain and the United States focusing on six pest species: Helicoverpa armigera, H. zea, Heliothis virescens, Ostrinia nubilalis, Pectinophora gossypiella and Sesamia nonagrioides. They found that in only one of these species – H. zea – had the frequency of resistance genes increased substantially.

One explanation for the evolution of resistance in H. zea is the observation that resistance to the Bt toxin Cry1Ac appears to be the dominant trait. This greatly reduces the effectiveness of refuges, since the resistance genes aren’t diluted out as effectively as they would be if they were recessive.

Helicoverpa zea has not evolved resistance in all areas – populations in Arkansas and Mississippi had done so, but those in North Carolina had not. This was attributed to differences in the effective refuge sizes:

Gustafson et al. [2006] meticulously estimated that the effective refuge abundance during each of three generations when H. zea fed on cotton was 39% in Arkansas and Mississippi and 82% in North Carolina. With these refuge sizes, H. zea is projected to evolve resistance after 9 years in Arkansas and Mississippi. By contrast, in North Carolina, resistance evolution should take >20 years, with the expected resistance allele frequency still <0.005 after 10 years.

However, the evolution of resistance has not led to any crop failures. Even where resistance has evolved, most populations are not resistant, and even among resistant strains “Cry1Ac in Bt cotton still caused 48–60% larval mortality”. In addition, spraying is still used to combat large pest outbreaks, and “pyramided” transgenic plants which contain both Cry1Ac and a second Bt toxin, Cry2Ab have been introduced. Resistance to one Bt toxin does not convey resistance to the other, so it’s far more difficult for pests to evolve resistance to plants producing both toxins.

Tabashnik, B.E., Gassmann, A.J., Crowder, D.W., Carriére, Y. (2008). Insect resistance to Bt crops: evidence versus theory. Nature Biotechnology, 26(2), 199-202. DOI: 10.1038/nbt1382

Guardian of the grasses

Anoop Sindhu and colleagues report on a gene that may have played a key role in the evolution of grasses. The gene, Hm1, provides resistance against Cochliobolus carbonum race 1 (CCR1), a fungus that is capable of attacking and killing corn at any stage of its development (images of CCR1 infection). While CCR1 is only known to affect corn, the gene Hm1 and its relatives are present throughout the grass family, but are absent from other lineages.

CCR1 is only known as a disease in Zea mays, but the Hm1 family of genes throughout the grass family. Sindhu and colleagues silenced the corresponding gene in barley. This resulted in barley that was susceptible to CCR1. The fungus is able to invade susceptible grasses through the production of Helminthosporium carbonum* (HC) toxin. The ability of Hm1 and related genes to resist CCR1 comes from an enzyme known as HC-toxin reductase (HCTR), which detoxifies HCTR.

A phylogenetic analysis of the Hm1-gene family showed that they were monophyletic – they all shared a common ancestor. Since it is present throughout the grass family, but is absent from all other groups of plants, it appears that the gene shares its origin with the grass family. This lead the authors to conclude that:

The maintenance of HCTR gene function in maize and barley, coupled with the unique phylogenetic position of the Hm1 gene (with no closely related orthologs in eudicots), suggests that Hm1 may have played a critical role in the evolution of most of our cereal crops. Given the devastating potential of CCR1 to kill susceptible corn, it is likely that this fungus or its ancestral form would have threatened the existence of grasses, or at least severely constrained their geographical distribution, had Hm1 not evolved to detoxify HC toxin. Thus, it seems likely that Hm1 served as a guardian of the grass family, allowing it to survive, thrive, and evolve into crops that feed the world.

*Helminthosporium carbonum is the asexual form of Cochliobolus carbonum. Since fungi are classified on the basis of their sexual structure, fungi whose fruiting bodies are unknown often end up being described as distinct species.

Sindhu, A., Chintamanani, S., Brandt, A.S., Zanis, M., Scofield, S.R., Johal, G.S. (2008). A guardian of grasses: Specific origin and conservation of a unique disease-resistance gene in the grass lineage. Proceeding of the National Academy of Sciences USA, 105(5), 1762-1767. DOI: 10.1073/pnas.0711406105 Open Access

Beginnings of agriculture in Europe

In the Winter 2007 issue of Planet Earth, Glynis Jones, Caitlin Buck,Mike Charles, Tom Higham and Sue Colledge talk about their project to date the spread of agriculture into and across Europe using the appearance of cereal grains. They found that agriculture spread rapidly from Greece (where it first entered Europe from the Middle East) along the Mediterranean coast to Iberia, but the spread inland came more slowly, in a “stop and go” fashion.

Previous studies of the spread of agriculture were based on proxies – wood charcoal and pottery – that were easier to date.  Improved technology allows the authors to date much smaller samples, opening up the possibility of actually dating the products of agriculture – charred grains.  While this can create false positives (after all, you can acquire grain through trade even if you aren’t growing it), it seems like a very powerful approach.

H/T Agricultural Biodiversity Weblog

New Michael Pollan book

Michael Pollan has a new book out: In Defense of Food.  From an interview with Grist:

The new book is called In Defense of Food: An Eater’s Manifesto. It’s a book that really grew out of questions I heard from readers after Omnivore’s Dilemma, which was basically so how do you apply all this? Now that you’ve looked into the heart of the food system and been into the belly of the beast, how should I eat, and what should I buy, and if I’m concerned about health, what should I be eating? I decided I would see what kind of very practical answers I could give people.

(Courtesy Bora). 

Pollan is one of my favourite writers.  The Botany of Desire is the best “Botany for the masses” book I have read.  The Omnivore’s Dilemna is a great book as well.  So when I heard mention of this new book, I was immediately interested.  Looking at the interview, it appears that the new book is along the lines of the piece he wrote for the New York Times earlier this year which began with

Eat food. Not too much. Mostly plants.

Pollan returns to this idea in the Grist interview. 

I spent a lot of time looking at the science of nutrition, and learned pretty quickly there’s less there than meets the eye, and that the scientists really haven’t figured out that much about food. Letting them tell us how to eat is probably not a very good idea, and indeed the culture — which is to say tradition and our ancestors — has more to teach us about how to eat well than science does. That was kind of surprising to me.

It really comes down to seven words: “Eat food, not too much, mostly plants.”

The interview also delves into reactions to The Omnivore’s Dilemna, and how it has affected things like the Farm Bill and Whole Foods.  With regards to the Farm Bill, Pollan says:

I was just on the phone this morning with a congressman (and by the way, they’re calling me, I’m not calling them at this point, and I think that’s interesting). There’s more politics around the farm bill — more grassroots politics, more reform politics — than there has been in a generation. At the same time, and as a result of that, there has been a defensive reaction that has been fierce.

It’s a great interview, the kind of thing I wish I could see live.  It’s well worth reading.

Fruit species blog

Fruit Species is a blog devoted to fruits from all over the world.  So far, there are 19 species on the page, including avocado, guava, rambutan (which I tasted for the first time a couple weeks ago) and soursop.  The descriptions include common and scientific names of the species and several paragraphs of information about each one.  The banner at the bottom of the page says “50 more fruits still stuck in my PC, do drop by again”.  I plan to do just that.

Courtesy Jeremy at Agricultural Biodiversity Weblog.