YOKOHAMA — Investing in agriculture in Africa to solve food shortages is more important than just reacting to the continent's present food crisis, according to the leader of a U.N. food aid organization.

"The real underlying problem is a long-term one; productivity growth in agriculture is going down," International Fund for Agricultural Development President Lennart Bage said in a Thursday interview with The Japan Times.

Productivity growth had been 3 percent to 5 percent about 20 to 30 years ago, but it has been 1 percent or 2 percent in recent years, said Bage, in Japan to attend the Tokyo International Conference on African Development in Yokohama.