CANBERRA, Australia: A global fall in agricultural research spending?- other than in China?- is slowing growth in farm output and will lead to higher world food prices for the first time in five decades, an economist said Tuesday.

Climate change and associated water shortages have contributed, but the productivity slowdown is "heavily related" to declining research spending since the late 1970s, said Philip Pardey, professor of science and technology policy at the University of Minnesota.

"The ultimate consequences of the productivity slowdown are that we're going to move away from a 50-year trend of declining real prices of food to moving back into a trend for increasing food prices," Pardey told The Associated Press on the sidelines of a conference here on world food security.

US farm productivity growth?- the increase in crop yield for an area of farmland under cultivation?- had slipped from 2 percent a year in 1990 to 1.1 percent in 2002, he said.

The slip varies from country to country although the slowdown is global. Pardey blames a lack of investment in improving crop strains and farm management techniques.

China has bucked the trend by maintaining agricultural research and development investment and with a corresponding high crop yield growth in staples such as wheat, rice, corn and soybeans, said Pardey.

Marco Ferroni, executive director of the nonprofit Syngenta Foundation for Sustainable Agriculture, agreed that falling investment in research on better farming practices and ways to produce hardier crop varieties that can thrive in poor soil or resist insects and disease were factors slowing farm productivity growth.

"Not every country is effected the same, but here we're talking about long-term trends and its down for most of the major world regions," Ferroni said.

Figures for 2000, the most recent global figures available, show that the United States contributed about a quarter of $33.7 billion of the world's private and public spending on agricultural research and development.

Of the $20.3 billion in public funding, the United States spent 19 percent and China 9 percent.

Pardey said increasing amounts of this spending was for research on the impact of farming on climate change and the threat of terrorism to food supply?- and not on increasing farm production.

The UN World Food Program executive director Josette Sheeran said in Canberra on Monday that most of the developing world is paying more for food despite drops in commodity market prices during the global economic slowdown, with 200 million people joining the ranks of the hungry in the past two years.