A three-day, U.S.-backed West African conference on genetically modified seeds has opened in Burkina Faso. The controversial scientific development started with the planting of transgenic cotton in some areas of Burkina Faso for the first time last year.

The United States is sponsoring the conference to promote the use of genetically modified seeds and an overall understanding of biotechnology in the West African region.

Members of the 15-nation Economic Community of West African States, ECOWAS, are attending the meeting in Burkina Faso, one of the first nations to accept testing of genetically modified crops. But some ECOWAS countries remain concerned about possible risks to human and environmental health.

Burkina Faso is one of Africa's poorest countries and its number-one cash crop is cotton. But the landlocked nation imports more products than it exports and relies heavily on outside food aid.

The United States is promoting the use of biotechnology which, it says, holds the promise of drought-resistant crops and the growing of African staples such as rice and cassava that would require less water.

But Jonathan Matthews, the coordinator of G.M. Watch, a British-based watchdog group specializing in genetically modified crops, says there are other ways that the United States could assist West Africa.

"This is being promoted by the United States. Now the United States has just been in trouble themselves with the World Trade Organization over their massive subsidies to cotton, which of course are hitting West Africa," he said. "So, if they really wanted to do something to help Africa, there are very simple things that they could do which do not involve an introduction of very sophisticated and expensive technology with a number of risks associated with it."

Last week, the World Trade Organization ruled against American cotton subsidies in a case brought by Brazil. The case stated that the United States paid more than three billion dollars to its cotton farmers in a move that affected global cotton prices.

Mr. Matthews also worries that the manufacturers of the modified seeds are not aware that many farmers in developing countries reuse seeds from year-to-year.

"Another of the problems that comes with this technology is that it is a patented technology and the company keeps commercial control over it," he said. "And that means that traditional practices of saving and reusing seed are not possible, or there is a danger that if they do occur then the company will come after the seed saver and actually seek financial redress through the legal system. And obviously, that is a much bigger issue for farmers in the developing world where seed saving is very customary."

The U.N. Food and Agriculture Organization says nearly half of the nations in Africa suffer from dire food shortages and that biotechnology could help feed billions of people during the next few decades.