September 8, 2005
From: StopSoybeanRust.com, 2 Sep 2005 [edited]

Second South Carolina County, Barnwell, found to have Asian soybean rust

South Carolina has confirmed soybean rust [ASR] in a sample taken 31 Aug 2005 from a field planted for potential use in insecticide trials at Clemson University's Edisto Research and Education Center in Barnwell County. Barnwell is 2 counties up from Hampton County, the site of the 1st ASR found in the state this year. Soybeans in the 2-acre Barnwell field were Maturity Group VI at growth stage R5-R6 with almost full-size seeds in the pods. As such, they were the earliest-planted soybeans on the Center.

John Mueller, Extension soybean pathologist at Clemson, put this additional information in his commentary yesterday in an e-mail co-written with David Howle, assistant director of regulatory services at Clemson, to pathologist colleagues yesterday: "The level of severity was higher than that observed in the Hampton County rust field. Approximately 30 per cent of the collected leaves had 1 or more ASR pustules on the bottom surface. Most of the affected leaves had 5 to 15 pustules. This indicates that we may have had spores produced by the initial pustules and we are seeing a second generation of pustules now. It also means that infection probably took place 10 to 14 days ago."

According to Mueller, the Hampton County field where ASR was observed on 15 Aug 2005 has been sprayed with a fungicide and he has taken several samples since the 1st observation of ASR in that field. "Development of ASR is apparently very slow, since it has been difficult to find pustules in any of our samples from the Hampton County field. We have sampled numerous other fields throughout South Carolina in the last 10 days without any other ASR detections other than at the Edisto Center field."

According to Mueller, we are assuming that ASR is still not widespread and is occurring primarily in more mature fields. ASR findings in Alabama, Florida, Georgia and Mississippi as well as in South Carolina are primarily in older soybeans, usually those in R4-R5 growth stage or later. As our soybean crop matures, we should expect to see more finds of Asian soybean rust, most likely in order from the southern to the northern part of the state.

"The levels of rust observed in this latest find, and our failure to find rust in many other fields, indicates our levels of rust are low and we have time to develop spray strategies for each of our fields. We do not need to 'rush out and spray,' but we do need to make good informed decisions on a field-by-field basis."

--
ProMED-mail
<promed@promedmail.org>

[The following is an update of the USDA National Map Commentary (updated: 8 Sep 2005). Calhoun County in South Carolina and Washington County in Georgia are the newest counties to report Asian soybean rust [ASR] in the Gulf States. Oconee County in Georgia is the furthest northern location where ASR has been found in 2005. Calhoun County in SC is the furthest east that ASR has been detected while Pearl River County in Mississippi is the furthest west that ASR has been reported in 2005. To date, Alabama has 13 counties reported positive with ASR; Florida has 22; Georgia has 15; Mississippi has 2; and South Carolina has 3. There were 35 counties
reporting ASR in August with 4 reports so far in September. New reports of ASR are expected to continue within states already reporting ASR and adjacent states to the north. With the potential movement of spores by Hurricane Katrina to the north, chances of deposition and infection increase beyond states that already have reported ASR. Weather conditions in the coming weeks will continue to drive ASR spread in the region.

Link: <http://www.sbrusa.net> - Mod.DH]

[see also in the archive:
Soybean rust, Asian strain - USA (GA) (04) 20050905.2623
Soybean rust, Asian strain - USA (multistate)(04) 20050829.2556
Soybean rust, Asian strain - USA (GA)(03) 20050827.2531
Soybean rust, Asian strain - USA (AL)(03) 20050826.2528
Soybean rust, Asian strain - USA (AL)(02) 20050824.2496
Soybean rust, Asian strain - USA (SC) 20050818.2414
Soybean rust, Asian strain - USA (FL)(03) 20050815.2386
Soybean rust, Asian strain - USA (Multistate)(06) 20050808.2318
Soybean rust, Asian strain - USA (multistate)(05): susp. 20050806.2291
Soybean rust - USA (multistate)(04) 20050806.2289
Asian soybean rust, Asian strain - USA (multistate) 20050724.2133
Soybean rust, Asian strain - USA (AL) 20050715.2029
Soybean rust, Asian strain - USA (multistate)(03) 20050714.2005
Soybean rust, Asian strain - USA (multistate)(02): Florida 20050708.1938
Soybean rust, Asian strain - USA (multistate) 20050702.1868
Soybean rust, Asian strain - USA (LA) 20050624.1769
Soybean rust, Asian strain - USA (FL) (02) 20050620.1731
Soybean rust, Asian strain - Americas: alert 20050528.1476
Soybean rust, Asian strain - USA (GA) 20050505.1245
Soybean rust, Asian strain - USA (GA) 20050429.1196
Soybean rust, Asian strain - USA (FL): 1st report 2005 20050309.0693]