James and the Giant Corn Genetics: Studying the Source Code of Nature

November 17, 2009

Dr. Gebisa Ejeta on Investing in Agriculture

I mentioned Doctor Gebisa Ejeta before when he won the world food prize for his work developing striga resistant sorghum breeds. This is a man who began life… well his own words can say it better than I can paraphrase:

I was born of illiterate parents with little means and raised in a small village without schools in west-central Ethiopia. An only child, I was nurtured with with lots of love, but on a diet less than adequate even for body maintenance, let alone for growth and intellectual development. … I was rescued by a godsend from the United State of America…

I took that quote from his testimony before the Senate Committee on Foreign relations this past spring. It was a moving call to renew the international investments in agricultural research, and the training of plant scientists around the world, something the United State and the international community as a whole have let slide for the past two decades. The whole testimony is an excellent read (h/t to mary for pointing it out on the biofortified forums). If you have a few minutes, please take the time to read the whole thing here [pdf]. If you don’t, you surely have the time to read this single paragraph: (more…)

October 31, 2009

Predictable Spinning of Squash

I dont have any picture of pumpkins handy, so this watermelon (and fellow cucurbit) will have to do.

I don't have any picture of pumpkins handy, so this watermelon (and fellow cucurbit) will have to do.

What could be a more fitting topic for a Halloween post than cucurbits, the family of plants that (in addition to crops like watermelon and cucumber) include squash and pumpkins? Yeah, I know it’s a stretch.

A week ago a paper came out in PNAS (the proceedings of the national academy of sciences. A very prestigious journal, one step down from Science or Nature), that showed when an artificially inserted gene in squashes that provided virus resistance was introgressed into a wild related species it actually made them less fit. Short version: the wild squash also suffer from the virus which attacked domesticated squash but are also attacked by beetles, and the beetles prefer to eat squash without the virus. Tomorrow’s Table has a much better and more complete explanation of the research.

In that post the very first commenter predicted the result, that in this particular case a transgene (like most genes involved in domestication) was beneficial for farmers but not for wild plants, would be spun into “another failure for GMOs” when the real message is “we were worried about pollen drift, but in this case it turns out we didn’t have to be.”

He was right. (more…)

October 20, 2009


Filed under: agriculture,Plants — Tags: , , , , , , — James @ 1:13 am
Grafted Apple Tree

Grafted Apple Tree

Imagine if all it took to replace a lost leg was to put another leg against the amputation site, tie up the wound and let the two grow together. We can do that with plants! We’ve been doing it for thousands of years and it is an important part of crops production for woody plants (think fruit trees).

The technique is called grafting and it really is almost that simple. A branch or stalk* from one plant is cut and attached to another plant of the same or a related species**, making sure to line up the vascular tissue*** of the cut branch and host plant. That connection is covered with grafting wax or grafting compound which keeps the exposed ends of the cuts from drying out which would stress or kill the cells. (more…)

October 17, 2009

Bill Gates at the World Food Prize

Filed under: agriculture,Link Posts — Tags: , , , — James @ 1:07 pm

If you have a few minutes, take the time to either watch or read the speech Bill Gates delivered at the World Food Prize in Des Moines. While I don’t care for the operating system that made him a multi-multi-billionaire, I don’t think anyone can argue that he is doing more good with his wealth than any other member of the superwealthy.

Africa is the only place where per capita cereal yields have been flat over the last 25 years. The average farmer in sub-Saharan Africa gets just over half a ton of cereal per acre. An Indian farmer gets twice that; a Chinese farmer, four times that; an American farmer; five times that. (more…)

October 15, 2009

Spoiled with Perfect Produce

From teddlerus on flickr

From teddleruss on flickr

Matt over at The Scientist Gardener put up an important post a couple of days ago where he related his own experiences touring a lettuce field:

The crop wasn’t in great shape, but we anticipated a decent harvest. We were shocked to learn that the field had already been harvested! Hundreds of perfectly edible heads lay all around us, left unpicked because they didn’t meet stringent appearance standards for consumer acceptance.

How big an issue imperfection is varies from crop to crop. For a crop like oranges it isn’t one at all, since there’s plenty of demand for orange juice, a use that don’t require visually attractive fruit. Now when it comes to something like cauliflower, or as Matt was talking about lettuce, there’s very little demand for anything other than fresh, whole produce. The rest just goes to waste rotting in fields.

In America it is an issue of consumer preference, and I couldn’t find any statistics on wastage to imperfect fruit. In the European Union it was until recently a matter of government policy. Twenty percent of produce was being thrown away for not meeting government size and shape criteria. This summer the restrictions were removed from 26 type of fruit and vegetables which was expected to cause price drops of up to 40% for some kinds of fresh produce. You could imagine something similar would happen in the US if we as consumers didn’t demand perfect fruits and vegetables, making healthy (if odd looking) food more affordable for everyone.

I’m not sure if there’s a call to action here. Just something to be aware of.

September 24, 2009

Herbicide Resistance

Filed under: agriculture,Plants — Tags: , , , — James @ 2:16 pm
Plant breeders can find natural resistance to pathogens. Some crops can be grown in regions where they have few or no natural insects attackers. But every crop with face the problem of weeds, other plants that threaten to steal light and nutrients. And the crops that sustain us will always suffer from an unfair handicap, as crop plants devote much of their energy to food production (whether that means fruits, roots, seeds, or even leaves) while weeds can devote all their energy to outcompeting their neighbors.
Since farmers as individuals and we as a species depend on growing fields of crops like like corn, eggplant or rhubarb and not weeds like kudzu, thistles or chickweed we need to protect our crops. A farmer can protect his crop physically, either sending people out with hoes to slay every plant but his own crops* or using a cultivator to turn over the soil between the rows, hopefully burying or slicing and dicing the majority of the weeds. The first costs money and is miserable for whoever does the work. The second burns extra fuel, bad from both global warming and cost perspectives, and increases soil erosion (top soil broken up by the plows of the cultivator can more easily be carried away by rainfall).
The alternative is for the farmer to defend his crop with herbicides (plant killing chemicals). The problem with this approach is to find chemicals that kill weeds but not the crop plants. Similar to the challenge of finding antibiotics which can kill the bacteria attacking a human body without killing the human her or himself, herbicide developers face the added difficulty that most weeds are much more closely related to the crops they’re competing with than bacteria and humans(which last shared a common ancestor more than a billion years ago). In many cases it is more comparable to finding a toxin that would kill mice, but not humans, at similar dose to body-weight ratios. And even when they find a suitable herbicide, it may have nasty effects on humans (and many herbicides do).
Herbicide resistant lines are can survive broad spectrum herbicides, herbicides that kill all plants, like glyphosate (Round-up when you the brand name version from Monsanto), glufosinate (Liberty) and Imidazolinone (Beyond). Without having to worry about finding chemicals naturally survivable by crop species, herbicides can be used that are far more effective at killing weeds, in addition to being less toxic to humans.** With more effective pesticides, farmers can stop using cultivation as an additional method of weed control, letting the soil remain unbroken, which reduces the loss of topsoil from erosion. The mistake I think a lot of people make is assuming all herbicides are equally bad. Given the choice I’d much rather get lost and wander into a field treated with glyphosate than a field treated with a quarter as much atrazine.
*The worst sunburn I ever got in my life came from a day spend hoeing a cornfield
**The MSDS for the active ingredient in round-up, glyphosate. Basically you shouldn’t rub it in your eyes or take a bath in it, but even then, the result would probably be irritation, not death. Extropolating from the LD50 in rats***(with apologies for nested footnotes), always a dangerous thing to do, a person of my weight would have to eat 500 grams of pure glyphosate to have an even chance of death. And that’s on top of it being classified as Group E (evidence that the chemical does NOT cause cancer)
***LD50 is a fancy way of saying how much of a toxin must be feed to a group of lab animals to kill half of them.

What herbicide resistance is, and why the trait is so valuable to farmers.

Spear Thisle

One of many enemies faced by crops, the spear thistle. Photo John Tann, Flickr

Plant breeders can find natural resistance to pathogens. Some crops can be grown in regions where they have few or no natural insects attackers. But every crop with face the problem of weeds, other plants that threaten to steal light and nutrients. And the crops that sustain us will always suffer from an unfair handicap, as crop plants devote much of their energy to food production (whether that means fruits, roots, seeds, or even leaves) while weeds can devote all their energy to outcompeting their neighbors.


April 16, 2008

Tomorrow’s Table

Filed under: Book Reviews,research stories — Tags: , , — James @ 2:35 pm

Believe it or not plant geneticists and the organic movement do share share common ground. It is the realization that conventional agriculture (meaning high input, in the forms of pesticides, energy intensive synthetic fertilizer, and drawing more water out of aquifers every year than is replaces by rainfall) is not going to be sustainable over the long term. I just finished reading a book that makes the case to proponents of organic agriculture that genetic modification of crop species can be a beneficial and powerful tool for developing a more sustainable, lower input system of agriculture that can still feed the six and a half billion people alive on the earth today, and the billions more than will be born in the coming decades. The book is called Tomorrow’s Table: Organic Farming, Genetics, and the Future of Food, and it’s written by a husband and wife who personally straddle the divide between the two movements. She’s a professor working with rice at UC-Davis, and he manages and teaches organic farming.

The first part of the book is really an introduction to the ideas behind organic farming and genetic modification. I think I’ve got a pretty good background and I’ll admit I skimmed quickly over chapters like “the tools of genetic engineering.” The real substance of the book is in the second half where the authors address some of the frustratingly common arguments used by those who vehemently oppose genetically engineering crops (for example: safety, pollen drift, intellectual property) and go on to talk about the benefits GM crops can and do bring to the environment, consumers, and growers.

While the authors do a good job of making the point that GM crops really are compatible with the principles of the organic movement, I obviously already agreed with the value of GM crops. What won me over about this book was the way Pamela Ronald describes the delicate dance of a plant biologist drawn into a discussion of genetic engineering with friends or family who are firmly convinced of the danger or immortality of the technology.

If you’re interested in the subject, a good short read that summarized a lot of the points in Tomorrow’s Table is an op-ed piece Pamela Ronald wrote for the Boston Globe called The New Organic. (I read the article before Tomorrow’s Table came out, and went straight from reading the article to pre-ordering the book on amazon.) Pamela Ronald also has recent started her own blog.

In closing I’d like to quote another plant scientist blogger who I’ve discovered (while searching for the link to the Boston Globe article): “I want people to know that I’m here. I am a scientist, I am reasonable, and I am a good person. . .I believe that the two types of scientists and farmers (sustainable agriculture and genetic engineers) need to communicate and work together. . .The partnership can only happen if every scientist and every person on each side of the issue works to share and understand each other.” – Anastasia at www.geneticmaize.com

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