Soybean Rust Update

— Written By

From Jim Dunphy, Extension Soybean Crop Scientist,

And Lindsey Thiessen, Extension Soybean Plant Pathologist

NC State University

To date (09/15/2017), Asiatic Soybean Rust (ASR) has been confirmed a little closer to most of North Carolina’s soybeans, in Barnwell County, SC. These soybeans were at stage R7, which is having at least one mature colored pod on 95% of the plants.

The closest rust on soybeans to Charlotte is now 145 miles, to Elizabeth City is 360 miles, to Fayetteville is 185 miles, to Murphy is 20 miles, to Raleigh is 235 miles, to Washington is 290 miles, to Wilmington is 210 miles, and to Winston-Salem is 210 miles.

ASR has now been confirmed on soybeans or kudzu in 49 counties in AL, 4 counties in FL, 14 counties in GA, 9 parishes in LA, 38 counties in MS, 2 counties in SC, and 1 county in TN.

Hurricane Irma has the potential to transport rust spores toward North Carolina soybeans. Although we do not expect a significant impact from these potential spores, late planted soybeans may be at risk. If you are concerned that ASR may affect your soybeans (between first bloom and R5), scout fields in an irregular pattern (e.g. zig-zag patterns) beginning 2 weeks after Hurricane Irma passes the region. If you suspect soybean rust, please submit a sample to the Plant Disease and Insect Clinic for confirmation.

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To date (09/11/2017), the nearest Asiatic Soybean Rust (ASR) confirmations have been in Union County, GA, and which is just across the state line from Murphy, NC, and Shelby County, TN, and Hampton County, SC. These reports are greater than 100 miles from soybean producing counties, with the exception of the Union County, GA observation (20 miles from Murphy).

The closest rust on soybeans to Charlotte is still 165 miles, to Elizabeth City is 380 miles, to Fayetteville is 215 miles, to Murphy is 20 miles, to Raleigh is 265 miles, to Washington is 310 miles, to Wilmington is 215 miles, and to Winston-Salem is 235 miles.

Hurricane Irma has the potential to transport rust spores toward North Carolina soybeans. Although we do not expect a significant impact from these potential spores, late planted soybeans may be at risk. If you are concerned that ASR may affect your soybeans (between first bloom and R5), scout fields in an irregular pattern (e.g. zig-zag patterns) beginning 2 weeks after Hurricane Irma passes the region. If you suspect soybean rust, please submit a sample to the Plant Disease and Insect Clinic for confirmation.

We recommend spraying a fungicide to prevent infection of ASR on soybeans if ASR is confirmed on soybeans within 100 miles of your field, and the soybeans are between first bloom and stage R5 (early seed development).

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To date (08/31/2017), It was announced earlier today that Asiatic Soybean Rust has been confirmed in Union County, GA, which is just across the state line from Murphy, NC. The soybeans were at stage R3 (early pod set). While this is much closer to Murphy than any previously announced find of rust on soybeans, it is the same distance from Winston-Salem (235 miles) as the Burke County, GA find, and farther from Charlotte and counties to the east than previously announced.

The field in Hampton County, SC which was previously announced as having rust has since been resampled, and rust was found on 40 of 50 leaves inspected, with from several to dozens of spores on each leaf. No rust was found on other fields nearby, and in adjacent counties, which were sampled.

The closest rust on soybeans announced to date to Charlotte is still 165 miles, to Elizabeth City is 380 miles, to Fayetteville is 215 miles, to Murphy is 20 miles, to Raleigh is 265 miles, to Washington is 310 miles, to Wilmington is 215 miles, and to Winston-Salem is 235 miles.

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To Date (08/23/17), South Carolina announced its first find of Asiatic Soybean Rust this year, in Hampton County. The soybeans were at stage R3 (early pod development), and only one of 50 leaves showed any detectable pustules. This is a little closer to many of our NC soybeans than any of the previous confirmed finds, at 380 miles from Elizabeth City, 265 miles from Raleigh, 310 miles from Washington, and 215 miles from Wilmington. Burke County, GA is still the closest find to Charlotte (165 miles), Fayetteville (225 miles), and Winston-Salem (235 miles). The closest find to Murphy is still Morgan County, AL.

Including detections of ASR on kudzu, the disease has been confirmed to date in 31 counties in Alabama, 4 counties in Florida, 9 counties in Georgia, 9 parishes in Louisiana, 20 counties in Mississippi, and 1 county in South Carolina.

We recommend spraying a fungicide to prevent infection of ASR on soybeans if ASR is confirmed on soybeans within 100 miles of your field, and the soybeans are between first bloom and stage R5 (early seed development).

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To date (08/21/2017):  It was announced over the weekend that Asiatic Soybean Rust (ASR) has been confirmed on soybeans in Georgia and Alabama fields that are closer to our NC soybeans than had been previously reported. The closest find to Murphy is a find in Morgan County, Alabama, which is approximately 165 miles from Murphy, and 350 miles from Charlotte. Almost all of the rest of the soybeans in the state are closer to a find in Burke County, Georgia, which is 165 miles from Charlotte, 395 miles from Elizabeth City, 225 miles from Fayetteville, 185 miles from Murphy, 270 miles from Raleigh, 330 miles from Washington, 245 miles from Wilmington, and 235 miles from Winston-Salem.

Including detections of ASR on kudzu, the disease has been confirmed to date in 31 counties in Alabama, 4 counties in Florida, 9 counties in Georgia, 9 parishes in Louisiana, and 20 counties in Mississippi.

We recommend spraying a fungicide to prevent infection of ASR on soybeans if ASR is confirmed on soybeans within 100 miles of your field, and the soybeans are between first bloom and stage R5 (early seed development).

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To date (08/18/2017), Asiatic Soybean Rust (ASR) has been confirmed on soybeans in Georgia, Alabama, and Mississippi this week. It was confirmed on soybeans that were at stage R3 (early pod set) in Decatur County, Georgia. And it was confirmed on soybeans that were at stage R5 (early seed development) in Lee and Perry counties, Alabama, and in Lee County, Mississippi. The closest of these finds to North Carolina soybeans is the Lee County, Alabama, find, which is approximately 190 miles from Murphy, 295 miles from Shelby, and 315 miles from Charlotte.

Including detection’s of ASR on kudzu, the disease has been confirmed to date in 20 counties in Alabama, 4 counties in Florida, 7 counties in Georgia, 9 parishes in Louisiana, and 13 counties in Mississippi.

We recommend spraying a fungicide to prevent infection of ASR on soybeans if ASR is confirmed on soybeans within 100 miles of your field, and the soybeans are between first bloom and stage R5 (early seed development).

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To date(08/10/2017), Asiatic Soybean Rust (ASR) has been confirmed on soybeans in two more states – Georgia and Alabama. It was confirmed on soybeans that were at stage R2 (full bloom) in Sumter County, Georgia, on August 8. And it was confirmed on soybeans that were at stage R5 (early seed development) in Autauga County, Alabama, and on soybeans that were at stage R4 (3/4 inch long pods in the top of the plants) in Elmore County, Alabama, on August 9.. The Georgia find is approximately 235 miles from Murphy, and 320 miles from Charlotte. The Alabama finds are more than 260 miles from Murphy, and more than 390 miles from Charlotte or any North Carolina soybean field north or east of Charlotte.

Including detections of ASR on kudzu, the disease has been confirmed to date in 9 counties in Alabama, 4 counties in Florida, 7 counties in Georgia, 6 parishes in Louisiana, and 6 counties in Mississippi.

We recommend spraying a fungicide to prevent infection of ASR on soybeans if ASR is confirmed on soybeans within 100 miles of your field, and the soybeans are between first bloom and stage R5 (early seed development).

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To date(07/25/2017), Asiatic Soybean Rust (ASR) has been confirmed on soybeans in two Gulf Coast states – Florida and Mississippi. It was confirmed on soybeans that were at stage R3 (early pod development) in Jackson County, Florida, on June 26. And it was confirmed on soybeans that were at stage R5 (early seed development) in Jackson County, Mississippi, on July 22. The Florida find is approximately 310 miles from Murphy, and 400 miles from Charlotte. The Mississippi find is more than 400 miles from any North Carolina soybean field.

Including detections of ASR on kudzu, the disease has been confirmed to date in 4 counties in Alabama, 3 counties in Florida, 3 counties in Georgia, 6 counties in Louisiana, and 1 county in Mississippi.

We recommend spraying a fungicide to prevent infection of ASR on soybeans if ASR is confirmed on soybeans within 100 miles of your field, and the soybeans are between first bloom and stage R5 (early seed development).

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The current status of rust in the continental US can be found anytime at http://sbr.ipmpipe.org

Written By

Photo of Maryanna Bennett, N.C. Cooperative ExtensionMaryanna BennettExtension Agent, Agriculture - Field Crops (252) 459-9810 (Office) Maryanna_Bennett@ncsu.eduNash County, North Carolina
Updated on Sep 18, 2017
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