All 10 of the top soybean-producing countries have disease problems that robbed them of an estimated $6 billion in 1998. That's according to Allen Wrather of the University of Missouri-Delta Center.

Wrather co-authored a study that gathered data on soybean disease losses from the 10 countries that produce 97.3% of the world's soybeans.

The latest data from three countries - Brazil, Bolivia and Paraguay - has not yet been submitted. But so far at least 895 million bushels, or 16% of world soybean production, was lostfrom disease during 1998. Loss could be up to 22% with data gathered from those three countries, Wrather estimates.

"The estimated losses due to disease in the top 10 soybean-producing countries during '98 were about 1.1 billion bushels, valued at $6 billion," he adds. That's figuring a $5.50/bu soybean price.

The study compared 1994 disease losses with those of 1998. The greatest losses in the U.S. last year were caused by soybean cyst nematode (279 million bushels), phytophthora root and stem rots (42 million bushels), charcoal rot (38 million bushels), sudden death syndrome (33 million bushels) and seedling diseases (29 million bushels).

U.S. SCN yield losses, pegged at 73 million bushels in 1994, nearly quadrupled by 1998. Scientists in Argentina, Brazil, Canada and China are also greatly concerned about SCN infestation, Wrather says. Disease losses in China, however, didn't change much from '94 to '98.

Argentina's greatest disease yield losses came from white mold, phytophthora root rot and SCN. The countries included in the study were: Argentina, Bolivia, Brazil, Canada, China, India, Indonesia, Italy, Paraguay and the U.S.

"These loss estimates reflect the intensity of the disease problems in each country for that particular year," says Wrather.

The basic objective of the research, funded by the United Soybean Board, is to show the impact of disease on the world soybean supply, he adds.

(J.A. Wrather, University of Missouri-Delta Center, Portageville, MO, T.R. Anderson, Harrow Research Center, Harrow, Ontario, et al)