The herbicide glyphosate could help suppress Asian soybean rust, a newly arrived disease that threatens the $18 billion US soybean industry.
"These early findings are promising," said R. James Cook, plant pathologist and interim dean of WSU's College of Agricultural, Human, and Natural Resource Sciences.
"However, further research must be conducted to validate the results under field use conditions. If these results translate to the field, this could provide another tool to soybean producers in combating Asian soy rust."
Washington State University (WSU), which carried out the research work with the U.S. Department of Agriculture's Agricultural Research Service (ARS) has applied for US and international patent protection through its Washington State Research Foundation, and intends to license this intellectual property to the agricultural and ingredients sector.
"This discovery embodies WSU's mission and values as Washington's land-grant university," said Jim Petersen, WSU vice provost for research. "WSU research programs are advancing the nation's economy and ensuring the global competitiveness of agricultural products."
The foundation has already reached a preliminary agreement with Monsanto, the producer of glyphosate-based Roundup agricultural herbicides. However Jerry Hjelle, vice president for Monsanto Worldwide Regulatory Affairs, cautioned that the data is preliminary.
"We will be carefully analyzing the research from WSU and gathering further information to determine product efficacy and use on Roundup Ready Soybeans," he said. "At this time, we strongly recommend soybean producers use fungicides labeled for treatment of Asian soybean rust."
Glyphosate herbicides are not currently registered or labeled to protect against or control Asian soybean rust and existing residue tolerances may not be adequate for this potential use. As it stands, it is a violation of federal law to use a glyphosate pesticide in a manner inconsistent with its labeling.
But this latest discovery could help change all this, and there is certainly a great deal of pressure from the soybean sector to find a solution. The American Soybean Association (ASA) has already expressed concern that fungicide supplies may be inadequate to control a major outbreak of soybean rust.
Indeed the U.S. Department of Agriculture USDA's Economic Research Service has warned that if an outbreak of soy rust did occur, the country's economy could lose between $240 million and $2 billion annually, depending on the severity of the crisis. The United States currently supplies about 40 percent of the world's soybean trade.
Over 5 percent of US soybean producers intend to decrease acres due to rust, said a recent report by the Delta Farm Press, though most still remain unconcerned about the disease. Farmers most concerned are located in the Southeast, where 29 percent of soybean producers said that rust was a factor in their planting decisions.
Of this group, 63 percent said they intended to decrease acreage because of the affliction.