Michelle Obama digs up the White House lawn

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The Obamas have started planting their garden with 55 varieties of vegetables — from a wish list of the kitchen staff — grown from organic seedlings started at the Executive Mansion’s greenhouses.

“The Obamas will feed their love of Mexican food with cilantro, tomatillos and hot peppers. Lettuces will include red romaine, green oak leaf, butterhead, red leaf and galactic. There will be spinach, chard, collards and black kale. For desserts, there will be a patch of berries. And herbs will include some more unusual varieties, like anise hyssop and Thai basil”. A White House carpenter, Charlie Brandts, who is a beekeeper, will tend two hives for honey.

If we all dug up our lawns, planted 55 kinds of vegetables and tended it very carefully, the world would be a better place. That said, who has time? Certainly not the Obamas. The White House grounds crew and the kitchen staff will do most of the work.

Still, I love the symbolism of it, and though it will be costly (vegetables harvested from showcase gardens such as the Obamas’ are much more expensive than produce from an organic commercial farm), it will provide a great education tool for the fifth graders that will help tend the farm and for White House visitors.

I hope one of her assistants plants some corn and teaches them about insects and disease. She can show them how to feel the tip of a mature ear to see if it is filled out. As we described in “Tomorrow’s Table”, they may discover some ears with hollow spots created where a corn earworm has been feeding.

The insect deposits its eggs on the corn silk that trails out of each ear of corn. When the larvae hatch, they crawl down the silk into the tip of the ear and begin to feed on the kernels. The kids can open up a couple of ears and see the big, fat, healthy earworms, writhing with irritation at being disturbed from such a luscious feast. They can laugh when they learn that the black stuff in the tips of the ears is called “frass,” a euphemistic word for insect poop.

Will she teach them ways to control for this pest? The corn earworm is not a picky eater and will eat almost any crop that we rotate in such as tomatoes, beans, or lettuce, and the adult moth is a good flyer. Even conventional breeding has failed to solve this problem because scientists have not yet been able to find a corn gene that gives protection from earworm. So organic controls dont work very well for the corn earworm making it difficult to control this pest on organic farms. Most organic farmers and consumers accept this problem in exchange for the benefits of not spraying insecticides.

There is one approach that works though. Bacillus thuringiensis is a bacteria that produces a toxin (called Bt toxin) that kills a narrow range of moths and butterflies. French farmers first started using Bacillus thuringiensis in the 1920s but it wasn’t available commercially in France until 1950s, and then in the United States in the 1950s. Today Bacillus thuringiensis is cultured in industrial production facilities and sold either as liquid or a powder with some additives to make it flow and mix better. After it is combined with water and sprayed in the field, caterpillars eat the bacteria in the form of spores and toxin. The toxin destroys the gut walls of the caterpillars and spores and other gut bacteria invade its body. This approach is an example of ‘biological control,’ using live organisms to combat pests and disease. Organic farmers have been using Bt as a “natural” insecticide to control insect pests for 50 years. It doesn’t work to control earworms on sweet corn, however, because the worm is burrowed deep within the ear, where the Bt spray cannot reach.

This is why geneticists engineered corn with the Bt gene. GE sweet corn is resistant to the earworm. I hope the First Lady plants some GE sweet corn next to the conventional variety so that this summer the Obamas and the kids could see firsthand how it resists pests and that it tastes the same. There will be less frass to giggle about but more sweet corn.


Sweet Corn Infected with Corn Earworm. On the left are three ears of late-season organically grown sweet corn. On the right are three ears of GE sweet corn containing Bt (Courtesy of Fred Gould, North Carolina State University).

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Pamela Ronald is Professor of Plant Pathology at the University of California, Davis, where she studies the role that genes play in a plant’s response to its environment. Her research focuses on the genetics of rice. With her husband, she co-wrote Tomorrow's Table: Organic Farming, Genetics and the Future of Food. She writes a blog of the same name.