• Asian soybean rust has been detected in southeast North Carolina.
• Late planted soybeans make good target for rust in North Carolina.
• It's time to spray for rust in most of southern North Carolina.
NORTH CAROLINA State University Soybean Specialist Jim Dunphy reports an early find of Asian Soybean Rust in Scotland County, N.C.
Soybean growers in North Carolina have been continually delayed in planting and spraying this year due to excessive and continuous rainfall,
The result is a late-planted conventional crop and record late-planted double-crop beans,
And the news got even worse last week as Asian Soybean Rust was reported in Scotland County in the southeast part of the state.
North Carolina State Soybean Specialist Jim Dunphy reports, “There were pustules on 5 out of 50 leaves examined, and these were sporulating. Sentinel plot samples from Lenoir and Cherokee were negative for rust.”
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This is the first find of rust in North Carolina in 2013 and puts it close enough to much of southern and southeast North Carolina to warrant a fungicide recommendation for soybeans that have started blooming, and do not yet have full sized seeds in the top four nodes of the plant.
The closest confirmed rust on soybeans to the North Carolina crop is now approximately 80 miles from Charlotte, 210 miles from Elizabeth City, 35 miles from Fayetteville, 90 miles from Murphy, 85 miles from Raleigh, 145 miles from Washington, 155 miles from Wilmington, and 110 miles from Winston-Salem, N.C.
“Rust has progressed at a faster rate this year than in years past. With a late soybean crop, the odds are increased that growers will need to apply a fungicide. Now is the time to spray a fungicide in much of the state, and to check spray equipment and be sure to have the proper nozzles for applying fungicides in the other parts of the state,” Dunphy says.
“We do not recommend spraying soybeans that have not started blooming with a fungicide to control soybean rust. Such pre-bloom applications have seldom improved yields.
“Once soybeans start blooming, we would recommend spraying if rust has been confirmed within 100 miles of the field,” he adds.
Rust has now been confirmed this year on soybeans in 70 counties/parishes in eight states (Louisiana, Florida, Alabama, Mississippi, Georgia North Carolina, South Carolina and Arkansas).
One day prior to the find in North Carolina, rust was reported in Pike, Perry, Walthall, Franklin, Bolivar and Sunflower counties in Mississippi and in Choctaw, Sumter, Pickens, Marengo and Hale counties in southwest Alabama.
And, a day prior to these finds, the disease was detected in Taylor County, Ga., and in four new counties in South Carolina, including Anderson, Edgefield, Lexington and Newberry.
The rapid spread of soybean rust from south to north this year is especially troubling for growers who planted soybeans well into July, which puts them in a vulnerable growth stage for the disease.
These late-planted beans are already expected to produce lower yields and the prospect of adding costly triazole fungicides to combat Asian Soybean Rust is not going is not going to be good news.
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