Johannesburg, South Africa ? As the World Summit on Sustainable Development begins here today, delegations are expected to debate sharply the link between rich nations’ agricultural subsidies and developing countries’ food shortages.

“We want an even playing field,” said Peter Rammatula, president of South Africa’s main farmers’ union, who hopes to lobby U.S. officials during the summit. “How can a farmer in Africa compete against the deep pockets of the U.S. government?”

More than 100 heads of state are expected at the summit, scheduled to run through Sept. 4, but President Bush will not be among them. U.S. Secretary of State Colin Powell and Christie Whitman, administrator of the Environmental Protection Agency, will represent the United States.

Various governments and activist groups have vowed to bring up the issue of farm subsidies. As Western countries preach globalization and press developing countries to open their markets, the rich nations’ refusal to curtail farm subsidies has left them open to charges of double standard and hypocrisy.

U.S., European and Japanese farmers get billions of dollars in farm subsidies, and then dump their crops in the world market where it depresses the prices of crops produced in poor countries, said Per Pinstrup-Andersen, director of the International Food Policy Research Institute, a Washington, D.C., think tank.

“The rich countries are practicing a double-standard when it comes to their trade policies, and it is unethical,” Pinstrup-Andersen said.

U.S. officials acknowledge that farm subsidies hurt small farmers in Africa. Last month, the Bush administration proposed a global agreement to slash subsidies, but insisted Europe and Japan must go along.