Return of the Potato Blight


Irish infestationGlobal blightA resistant spud?The poor farmers' stake

Peruvian farmers examine potatoes at a farmer field school. One man records data, while a couple of kids look on. Schools like this help knit agricultural researchers to the real needs of farmers.

All photos this page courtesy Rebecca Nelson, International Potato Center






















Using simple symbols, a farmer records data from a field trial. For a low price, researchers can get a wealth of real-world data.


A potato field with a farming family.In the field
Potatoes are much more than just french fries or fish 'n chips. They are a subsistence food and cash crop for people in many parts of the world -- highly productive, and even highly nutritious.

Chart compares total production for the year 2000 of rice, maize, wheat, potatoes and soybeans

Potatoes are a major source of food for the world. Total spud production was nearly twice the total production of soybeans, but less than total production of rice, maize (corn) and wheat. Source: FAOSTAT

Rebecca Nelson, who until recently directed late blight program at the International Potato Center (CIP), worries about late blight not for its effects on mechanized agricultural monocultures, but how it will affect the tiny farms, patches, kitchen gardens and postage-stamp fields in the Third World.

When late blight or an insect strikes these places, farmers (if they can afford it) often reach for their leaky backpack sprayer before they even understand the problem -- or exactly what's in the sprayer, what harm it might do, or the other possible solutions. Nelson, who now directs the Mcknight Foundation's Collaborative Crop Research Program, says many farmers don't know germ theory -- that microbes, not evil spirits or ill winds, cause disease.

Sudden death
Blight spores are invisible, and late blight kills quickly, so farmers need advance knowledge if they want a chance of making quick decisions that might save their crops after blight strikes.

The education may take place in "farmer field schools," which were invented to help Asian rice farmers deal with disease. The basic tenet is germ theory. "If you were an obstetrician and didn't know the germ theory, a lot of your patients would die," she says. "If someone told you washing your hands would magically cure the problem, you might or might not do it. But if you knew you were carrying microscopic, fatal organisms on your hands, you'd start washing -- and your patients would stop dying."

A farmer writes on a wall chart, tracking the progress of the trialby drawing smiling and frowning faces next to potato variety names.The field school method involves "facilitating a discovery process on the farmers' part," Nelson says. "By providing mini-microscopes and designing a set of activities that reveals the wonders of the microbial world and its causes and effects, they get the message better than if we just explain." With plant-killing germs, knowing the enemy is the first step toward a cure. "As researchers, we try to generate new information," she says. "But if the farmers don't know that there are germs out there, why bother coming up with new information?"

Field schools also:

Help Third World agricultural researchers stay in touch with farmers' real needs ("We learn how farmers work in a complex environment, and they decide what they want, and we learn from that," says Nelson. "Traditionally, we have had trouble getting our 'improved technology' to the supposed beneficiary; it either never gets there, or it turns out not to be quite 'improved' enough").

Distribute disease-resistant seeds. (Researchers have been frustrated that farmers reject partly resistant varieties. Data from on-farm experiments demonstrates the benefits, increasing acceptance).

field-test new varieties and techniques -- helpful because farm-extension organizations are always short of money and trained personnel.

Testing, 1, 2, 3

The International Potato Center is now testing farmer field schools in seven countries. In 2000, farmers at 19 locations in Peru tested 50 new blight-resistant varieties of potatoes created the Center's breeders. "The effects of resistance are very dramatic," says Nelson.

"A resistant varieties that the farmers really liked yielded literally 10 times as much as a susceptible variety in our three-year data set." Preliminary results show that farmers did ask for more resistant seed and greatly increased their knowledge of plant pathology.

Holding a laptop computer, a man enters data. Five or six men look on.Farmer field schools allow researchers and farmers to work together to solve insect and disease problems. In Peru, data enters the digisphere.

Globally, late blight costs developing countries a very approximate 15 percent of the crop, worth about $2.75 billion. Nelson says these farmers also spend another $740 million for fungicidal sprays. The cost may seem low, but if you remember the Irish famine, you know that starvation can result when crop failures are exacerbated by unfair distribution of land, reliance on single crops, and political oppression.

Nelson, who has worked extensively on farming in developing countries, insists that famine is not just history. "People still get peeved about the Irish famine, but for some reason there's a failure of outrage at the present hunger of 800 million or a billion people."

Spend the night with our blight bibliography?



    The Why Files     There are 1 2 3 4 pages in this feature.
Bibliography | Credits | Feedback | Search