The three-day conference beginning Monday in Sacramento will be led by U.S. Agriculture Secretary Ann Veneman.
Veneman has argued that biotechnology can go a long way toward feeding the world's 800 million people who consistently suffer from hunger by boosting global production of grains and other crops.
"To meet the goal of food security, agriculture productivity must be accelerated in areas where hunger and malnutrition are worst," Veneman told reporters this week.
USDA will spend about $3 million on the Sacramento conference, largely to showcase agricultural biotechnology.
Also on Monday, President Bush is due to address a biotech industry conference in Washington. In a May 21 speech, Bush took on the European Union and its 5-year-old ban on approving new biotech products.
Bush argued that policy has rippled across the globe, stirring opposition to biotech foods and hindering anti-hunger efforts in Africa.
Bush's remarks stirred biotech opponents, who viewed his speech as another attempt to globalize American products to the detriment of human health, the environment and small farmers in developing countries.
Protest marches, "teach-ins" and other anti-biotech events are scheduled for Sacramento by activist groups including Friends of the Earth and the Sierra Club.
"It's a false promise to say that current engineered crops will feed the world when U.S. officials are saying current crops would not perform well under African growing conditions," said Larry Bohlen, spokesman for Friends of the Earth.
Amadou Kanoute, regional director for Consumers International Office for Africa in Zimbabwe, told reporters in Washington that the spread of U.S. biotechnology would put small-scale African farmers, the backbone of the continent's farm sector, at a disadvantage.
"You will plunge Africa into greater food dependency," Kanoute said.
AMERICA GOES GMO
Biotech crops now grown are mostly for animal feed. But with Missouri-based Monsanto Company's recent move to commercialize a human food staple, biotech wheat, the debate has become more emotional.
Genetically-modified seeds are engineered to repel predatory insects and to withstand weed killers. The result, according to proponents, is higher yielding crops that are easier to grow and maintain.
In the 1990s, American farmers began embracing the new technology and now 75 percent of soybeans, 34 percent of corn and 71 percent of cotton come from gene-altered seeds.
A May 2002 USDA report concluded that biotechnology reduced total pesticide use by about 6.2 percent in 1997. Those savings can be significant in a country that used 164 million pounds of herbicides on corn fields alone, according to the United States Department of Agriculture.
The USDA report said that for crops such as soybeans that did not see much decrease in chemical use, the environmental benefit of biotech crops was that farmers could use less toxic chemicals.
But some consumers, especially Europeans, argue that not enough is known about the health and environmental impact of biotech food, even if chemical use is reduced.