Dennis could spread Asian soybean rust
It's possible for remnants of Hurricane Dennis to bring more than rainfall to the Midwest's parched fields: The storm clouds also could carry spores of a potentially devastating soybean fungus, Asian soybean rust.
The risk is still very low in Nebraska, according to agricultural extension officials, but they are alert.
"We're very intersted in what Dennis does," said Randy Pryor, agricultural extension educator in Wilber. "I encourage Nebraska producers to get timely updates from Loren Giessler at the University of Nebraska website. (http://www.soybeanrust.unl.edu)
"It's important we have this localwebsite, because after this storms, the rumor mill gets a little wacky," Pryor said. "Only facts get published on this website."
When Dennis made landfall along the Gulf Coast Sunday, it swept an area of southwestern Alabama where fields are infected with soybean rust, said Purdue University plant pathologist Greg Shaner. The storm then moved into the Tennessee and lower Ohio valleys. On Tuesday rain was falling across Missouri and Illinois.
Shaner and Pryor said farmers and agricultural scientists nationwide will be looking for any signs over the next few weeks that the fungus has spread.
U.S. soybean plants have little or no resistance, Pryor said. For the fungus to take off, its spores must fall on soybean leaves that remain wet for six to eight hours.
The rust appears as pustules on the leaves of soybean plants. Heat and high humidity could encourage its development.
Fungicides can control soybean rust, but only if they are applied immediately after it is detected.
It is expensive to treat, Pryor said, and would threaten a soybean crop already stressed by low rainfall.
Soybean rust has not caused any significant damage in the United States since it arrived in 2004 from South America — likely on the winds of Hurricane Ivan.
The fungus was confirmed in eight states last year, but so far this year, active infections have been confirmed only in Alabama, Florida and Georgia, but not widespread.
The fungus has not been found in Nebraska, but was found last year as nearby as southeastern Missouri.
The rust cannot overwinter this far north, Pryor said,
Last year, the fungus cost farmers in Brazil about $1 billion in crop losses and fungicide treatments. Yield losses have ranged from 10 percent to 80 percent in infected soybean fields in that nation.
Coanne O'Hern, a soybean rust detection coordinator with the USDA, said because the fungus is a relatively new arrival in North America, plant pathologists are uncertain how it will impact the nation's soybean crops.
"We just don't know what soybean rust might do in the United States. This is really the first full growing season with this fungus," she said.
Nebraska and other states have sentinel soybean plots that are examined for the presence of the fungus. There are 48 in Nebraska, checked weekly, Pryor said.
If the rust showed up as far north as Kansas or northern Missouri, he said, then the red flags would go up.
"It's been a quiet season thus far," he said. "So that's been good news for soybean producers in Nebraska. I think the dry weather south of here did not allow development as quickly. That's been the good news of the season."
On the Net:
University of Nebraska site: http://www.soybeanrust.unl.edu
USDA soybean rust information: http://www.usda.gov/soybeanrust/
The risk is still very low in Nebraska, according to agricultural extension officials, but they are alert.
"We're very intersted in what Dennis does," said Randy Pryor, agricultural extension educator in Wilber. "I encourage Nebraska producers to get timely updates from Loren Giessler at the University of Nebraska website. (http://www.soybeanrust.unl.edu)
"It's important we have this localwebsite, because after this storms, the rumor mill gets a little wacky," Pryor said. "Only facts get published on this website."
When Dennis made landfall along the Gulf Coast Sunday, it swept an area of southwestern Alabama where fields are infected with soybean rust, said Purdue University plant pathologist Greg Shaner. The storm then moved into the Tennessee and lower Ohio valleys. On Tuesday rain was falling across Missouri and Illinois.
Shaner and Pryor said farmers and agricultural scientists nationwide will be looking for any signs over the next few weeks that the fungus has spread.
U.S. soybean plants have little or no resistance, Pryor said. For the fungus to take off, its spores must fall on soybean leaves that remain wet for six to eight hours.
The rust appears as pustules on the leaves of soybean plants. Heat and high humidity could encourage its development.
Fungicides can control soybean rust, but only if they are applied immediately after it is detected.
It is expensive to treat, Pryor said, and would threaten a soybean crop already stressed by low rainfall.
Soybean rust has not caused any significant damage in the United States since it arrived in 2004 from South America — likely on the winds of Hurricane Ivan.
The fungus was confirmed in eight states last year, but so far this year, active infections have been confirmed only in Alabama, Florida and Georgia, but not widespread.
The fungus has not been found in Nebraska, but was found last year as nearby as southeastern Missouri.
The rust cannot overwinter this far north, Pryor said,
Last year, the fungus cost farmers in Brazil about $1 billion in crop losses and fungicide treatments. Yield losses have ranged from 10 percent to 80 percent in infected soybean fields in that nation.
Coanne O'Hern, a soybean rust detection coordinator with the USDA, said because the fungus is a relatively new arrival in North America, plant pathologists are uncertain how it will impact the nation's soybean crops.
"We just don't know what soybean rust might do in the United States. This is really the first full growing season with this fungus," she said.
Nebraska and other states have sentinel soybean plots that are examined for the presence of the fungus. There are 48 in Nebraska, checked weekly, Pryor said.
If the rust showed up as far north as Kansas or northern Missouri, he said, then the red flags would go up.
"It's been a quiet season thus far," he said. "So that's been good news for soybean producers in Nebraska. I think the dry weather south of here did not allow development as quickly. That's been the good news of the season."
On the Net:
University of Nebraska site: http://www.soybeanrust.unl.edu
USDA soybean rust information: http://www.usda.gov/soybeanrust/
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