"Only in Africa are there angry, tired and hungry farmers," said Adesina. He stressed the need to offer agricultural subsidies because "there is no other agriculture in the world that is not subsidized."
The continent already imports about 25 percent of its food, and one in three Africans suffer chronic hunger, while the population is expected to more than double to 1.8 billion people in 2050, the background statement said.
African agriculture faces such hurdles as unstable governments, outmoded techniques, poor seed stocks, poverty, climates prone to drought and flooding, as well as difficult market access because of poor transportation and trade barriers.
"If you really want to help Africa, build roads, build infrastructure (to get produce to markets). Countries may not build roads, but roads build countries," said Gerard Klijn, managing director of Global Trading & Agency BV, a Dutch company that brokers produce from the developing world.
The conference, with such delegates as 1970 Nobel Peace Prize winner Norman Borlaug, brings together public agencies, private investors and government officials to address a broad range of African agriculture topics, including financing, market access, improved crop yields, the role of women and the threat of climate change.
In 2004, Annan called for a revolution to "drive African farming communities from subsistence farming to sustainable modern agriculture and rural transformation."
In 2006, Norwegian government agencies and private industry responded by calling the first Green Revolution conference, and are now hosting the second, which lasts through Saturday.
There are signs of hope.
Last year, Malawi went from a more than 40 percent deficit of maize to a 25 percent surplus due to a new program of government farm subsidies, allowing it to export grain for the first time in a decade.
"This is the first Africa Green Revolution country," said Pedro Sanchez, of the Earth Institute at Columbia University. He said government subsidies of 75 percent for fertilizers helped the country double its maize production in one year.
"The government of Malawi had the courage to do the right scientific things," said Sanchez.
He said 1 ton of maize, as international food aid to Africa, costs about $670 (500 euros), while increasing production from African fields by the same amount costs roughly $80 (60 euros).
However, Klijn, of Global Trading, said that rush to increase production can bring risks, such as flooding he recently saw in Malawi because forests were cleared to free up farmland.
"Yes, we want to grow much more but not at the cost of deforestation," he said. Klinj also warned that a sudden explosion in African production could create a glut and a price collapse unless the types of crops are carefully managed.
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