COLUMN ONE : Latin Poor Turning to ‘Pop Tech’ : Peasants in South America make meager resources go further by such means as hydroponic gardening, solar stoves and harvesting fog.

No need for pesticides, Colombian agronomist Cesar Marulanda was telling 20 women. Just brush the aphids from the young lettuce leaves like this. “They fall off, and they don’t have much chance of returning.”

Marulanda was talking about hydroponics--the growing of plants, not in soil, but in nutrient-rich solutions or moist, inert materials--and the women were paying close attention. Some were taking notes.

Hydroponic gardens are producing hundreds of heads of lettuce at a cost of less than 10 cents each in the Santiago neighborhood of La Pintana. With lettuce selling for up to 50 cents a head, Marulanda observed, “A lot of people would love to have that kind of a business.”

Importantly, it’s a business the poor here can afford to get into. Costs are kept low by the adaptation of hydroponic technology to whatever cheap materials are available, such as used wood for the frames of planting beds, discounted plastic sheeting for waterproof liners, and coal cinders and rice chaff for inert material to support roots as they soak up a nutrient solution of water and inexpensive chemicals.

Through the clever use of meager resources, such so-called popular technology is helping Latin America’s poor live a little better. Low-cost, make-do technologies include cheap solar stoves, simple contraptions for producing bio-gas fuel and cultivated fungus to combat weevils that destroy stored potatoes.

While popular technology is not new, “it is growing, it is increasing,” said Jaime Parra, director of the Center for Studies in Technologies Appropriate to Latin America, a private Chilean foundation.

Parra’s Valparaiso center was founded in 1979 by Chilean exiles returning from Europe, where popular technology was part of a “back-to-basics” movement among disillusioned urbanites. “To speak of popular technology in Chile at that time was like speaking in Chinese,” he recalled.

Popular technology had long been regarded as a stopgap solution to problems of poverty that eventually would be solved by economic and social development. But the persistence of Latin American poverty, even when economies are growing--with the poor increasing to 183 million from 113 million over the past two decades--has altered the perception of such technologies as only “temporary.”

A worldwide trend toward energy-saving, ecologically sensitive technology also has provided a vigorous boost, Parra said. “It is a nonviolent technology, and it is a technology that harmonizes with the environment.”

Parra’s center has developed do-it-yourself devices that use solar energy to heat water and to dry fruits and vegetables for storage.

A simple example of popular technology is the center’s design for what Parra calls a “witch’s stove” that can be made from a cardboard box, which is insulated with paper, sawdust, wool, feathers “or any material that is available to people and that has insulating properties.” After cooking for a short time on a conventional stove, the pot is enclosed in the heat-retaining box, where cooking continues without more energy consumption.

Parra’s center has calculated that the witch’s stove can save between 40% and 50% of the energy normally needed for cooking. For many poor families, cooking gas is the biggest energy expense.

Another project has been to scientifically evaluate the effectiveness of popular herbal medicines and develop recipes for home remedies, such as a solution for eye infections and a healing salve.

The center also has designed a house with a frame of wood but walls of chicken wire and mud. Researchers found that adding a little cement and straw to the mud, then allowing the mixture to ferment for two or three weeks before drying, greatly increased the dried material’s strength.

More governmental support is needed for private organizations working with popular technology, Parra said, and the attitudes of poor people themselves need to change. Many poor Latin Americans suffer from consumerism that favors advanced technology and store goods they cannot afford.

“They shun the simple life,” he said.

Even so, much already is being done around Latin America:

- In Chile, the Institute for Nutrition and Food Technology has designed a solar stove made by sticking pieces of mirror to a hand-molded plastic dish with the diameter of a truck tire. Residents of Villa Seca, a desert town in northern Chile where wood and other fuel are scarce, are making the stoves and selling them for about $30 each.

- In Peru, the International Potato Center has developed a method for cultivating an insect-killing fungus, Beauveria brogniartii , which is environmentally safe but kills Andean weevils. Farmers in the highland village of Chincheros are growing the fungus and using it in place of costly and dangerous chemical insecticides to drastically reduce weevil damage to stored potatoes.

- In Colombia, a private foundation known as Cipav works with peasants to make their small farms self-sufficient through popular technology. One device farmers assemble themselves is a large, inclined tube of plastic sheeting that is connected at the upper end to a hose. Decomposing manure and vegetable waste in the tube produce methane gas, which is hosed to a special cooking stove. A byproduct is rich fertilizer.

- In Bolivia, archeologists and agronomists have helped impoverished residents of Lacaya rehabilitate the agricultural technology of ancient ancestors. The raised-field system--in which large, rectangular platforms of soil sit a few feet above interconnected canals used for both irrigation and drainage--has increased potato yields by up to seven times.

- In Chile, a private foundation named the Corporation for Solidarity Development is working with residents of coastal valleys in the northern desert to harvest fog. A dense fog called camanchaca can be caught and condensed on rows of vertical fiber screens. Water collected along the bottoms of the screens can be used for household needs or for drip irrigation.

A three-volume catalogue compiled by the U.N. Development Program in the late 1980s provides hundreds of illustrated descriptions of other examples of popular technology. Many ideas in the book, entitled “Technologies in the Eradication of Extreme Poverty,” are currently being promoted by agencies and foundations in Latin America.

Some samples from the U.N. catalogue: homemade devices for baling hay, shelling peanuts, shucking corn, smoking fish, digging wells; plans for simple greenhouses, adobe stoves, solar fruit dryers and lumber dryers; an apparatus that makes gas from charcoal; formulas for making natural insecticides from tobacco or garlic, and a food cooler that uses water evaporation to cut 100-degree temperatures in half.

It is the U.N. Development Program that helped start the hydroponic gardening project in Santiago. Marulanda, the Colombian agronomist, is here under a U.N. contract.

As a result of the project, which started in 1986 and costs about $30,000 a year, at least 12,000 Santiago slum dwellers now are growing hydroponic vegetables.

The project’s initial goal was to help poor families supplement their diets with vegetables that they could grow easily and cheaply in small spaces.

“Later, we saw the possibility of selling, and when the people started making a little money, they became enthusiastic,” Marulanda said. “If you don’t awaken the entrepreneurial spirit, the project has no future.”

Now, the project’s Assn. of Hydro-Vegetable Producers sells produce to two supermarket chains.

The Corporation for Solidarity Development began implementing a pilot project here in June with funds of its own, from a government agency and from the U.N. Development Program.

Participants include about 50 residents of La Pintana and other neighborhoods of southern Santiago and 15 youths in a foster home institution. Hector Flores, project coordinator, said the first crops harvested in December included lettuce, green beans, carrots and baby onions.

“Today we have weekly production of about 1,500 heads of lettuce, and we expect to reach a production of 10,000 a month in March,” he said.

One of Santiago’s major supermarket chains has offered to buy the lettuce. Meanwhile, some of the producers sell their products in street markets.

“They sell everything they take,” Flores said.

Hydroponic produce has been in demand because an outbreak of cholera prompted the government to ban vegetables produced on farms irrigated with contaminated water. Hydroponic gardeners generally use potable water, whereas some truck farmers irrigate their land with water from rivers and canals that receive untreated sewage.

The family income of project participants averages about $120 a month. “They can generate income equal to what their husbands earn, or more,” Flores said.

Rosa Jara de Urra, a construction worker’s wife in La Pintana, has filled the narrow yard beside her small house with hydroponic planting beds.

“I have 22 beds,” said the 37-year-old Jara. “I left a little place there for the boys to play in.”

Small plastic flags hanging over the planting beds were there to keep bugs away. Grasshoppers give her the most trouble.

“I have cucumbers, lettuce and radishes--there, those two beds,” Jara said. “I have 600 heads of lettuce ready to sell in March. They are planted in stages to have sales all four weeks of the month.”

The money will go to “fix up the house, add a room,” she said. And thanks to popular technology, life will be a little better.