October 18, 2006
From: ProMED-mail <promed@promedmail.org>
Source: stopsoybeanrust.com [edited]
<http://www.stopsoybeanrust.com/viewStory.asp?StoryID=978>

Asian soybean rust was detected on soybean for the first time ever in Kentucky on Friday, 6 Oct 2006. Between then and now, it was found on soybeans in 7 counties in the western part of the state.

The infected counties are Caldwell, Christian, Hopkins, Lyon, Marshall, Todd, and Union. Last year, only Caldwell County had any rust, and that was on kudzu, discovered 11 Nov 2005.

The U.S. count is now 110 infected counties in 9 states. These new finds are much farther north than any other U.S. rust locations in 2006.

Don Hershman, plant pathologist with the University of Kentucky, posted this in today's state commentary on <http://www.sbrusa.net>:

"Soybean rust was detected on soybean for the first time ever in Kentucky on Friday, 6 Oct 2006. The find was in the corner of an otherwise mature sentinel plot located at the UK Research and Education Center in Princeton.
Incidence was about 40 percent to 50 percent, and severity around 10 percent. Then, between Sun 8 Oct and Tue 10 Oct, soybean rust was detected at various levels in six additional counties -- Christian, Hopkins, Lyon, Marshall, Todd, and Union Counties. All of the finds, thus far, are in the lakes region of west Kentucky. Finds were in "mobile plots," except for the Caldwell and Union County finds, which were in sentinel plots," he said.

"Incidence in additional counties was generally low (0.1 percent to 10 percent.) With the exception of the Hopkins County find, which had extremely low severity (<0.1 percent), severity in the other finds was around 5 percent to 15 percent.

"For all finds, the stage of pustules was mostly uniform," Hershman said.
"This suggests to me that a large number of spores blew in sometime over the past 2 weeks and cut a pretty large swath in west Kentucky. We are in the process of looking to the west and east to see if an even larger area of spore deposition and infection may have occurred. This find will have absolutely NO impact on the 2006 soybean crop in Kentucky or anywhere else for that matter," Hershman said. "In fact, soybean rust will 'go away' from Kentucky as soon as there is hard frost. It simply cannot survive this far north. However, these finds are of great importance to the soybean rust predictive models. Thus, we are making great effort to know the extent of infection before the frost hits (maybe tonight) or until there are no soybean leaves in which the rust can survive (the disease has NOT been seen in kudzu here). I am hoping to find a location that has decent infection that would provide for an educational opportunity or two."

"The bottom line is this: The soybean rust finds will not impact soybean in Kentucky or the U.S. this year. But, they will help us to refine soybean rust predictive models, which will help greatly with SBR management in future crops," Hershman said.

Source: <http://www.sbrusa.net>

[Byline: Marilyn Cummins]

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

[Asian soybean rust (ASR) is a plant disease caused by the fungus _Phakopsora pachyrhizi_ and was introduced into the USA in 2004. In addition to the crop plant soybean (_Glycine max_), cowpeas, green beans, and other edible legumes could be affected by the ASR pathogen which causes defoliation and yield reduction. Kudzu (_Pueraria lobata_, a.k.a. Japanese arrowroot) is an important alternate host for the pathogen in southern states of the USA.

This is the 1st report of ASR on soybean in Kentucky, USA, though it was found on kudzu in that state in November 2005. This is the most northern detection of ASR in USA in 2006. The article notes that at this late stage of the soybean crop season the impact will be minimal. This report will be added to a subsequent posting which will summarize all finds of ASR in USA since the last summary (20060915.2611) which was posted on 15 Sep 2006.

Maps:
Asian soybean rust outbreaks 2006
<http://www.sbrusa.net>

Pictures:
<http://www.dtnsoybeanrustcenter.com/index.cfm?show=65&mid=60&page=ALL>

Diagnosis cards (broadband best)
<http://www.aphis.usda.gov/lpa/issues/sbr/SBR_IDcard_11-04.pdf>

Links:
<http://www.sbrusa.net>
National commentary, updates from states, maps, chronology.

<http://www.stopsoybeanrust.com/mc_home.asp>
Latest news, articles, maps and tracking information.

<http://www.dtnsoybeanrustcenter.com/index.cfm?show=10&mid=31>
Latest news, articles and other information.

<http://www.stopsoybeanrust.com/mc_resources.asp>
More links on ASR. - Mod.JAD]

[see also in the archive:
Soybean rust, Asian strain - USA (IL): 1st report 20061014.2948 Soybean rust, Asian strain update 2006 (11): USA 20060915.2611 Soybean rust, Asian strain update 2006 (10): USA 20060815.2288 Soybean rust, Asian strain update 2006 (09): USA 20060802.2143 Soybean rust, Asian strain Update 2006 (08): USA 20060711.1898 Soybean rust, Asian strain update 2006 (07): USA 20060703.1830 Soybean rust, Asian strain update 2006 (06): USA 20060616.1667 Soybean rust, Asian strain update 2006 (05): USA 20060612.1642 Soybean rust, Asian strain update 2006 (04): USA 20060518.1402 Soybean rust, Asian strain update 2006 (03): USA 20060226.0622 Soybean rust, Asian strain update 2006 (02): USA 20060221.0568 Soybean rust - Mexico: 1st report 20060219.0546 Soybean rust, Asian strain update 2006 20060214.0482 Soybean rust, Asian strain - USA (GA) 20060208.0415 ProMED-Plant Disease Report: July - December 2005 20060201.0331

2005
----
Soybean rust, Asian strain - USA: 2005 disease summary 20051228.3694 Soybean rust, Asian strain - USA (KY)(02): confirmed 20051219.3640 Soybean rust, Asian strain - USA (multistate) (10) 20051218.3628 Soybean rust, Asian strain - USA (KY): 1st report 20051123.3404 Soybean rust, Asian strain - USA (multistate)(09) 20051101.3187 Soybean rust, Asian strain, kudzu control 20051006.2914 Soybean rust, Asian strain - USA (GA)(05) 20051005.2902 Soybean rust, Asian strain - USA (AL)(04) 20050917.2743 Soybean rust, Asian strain - USA (multistate)(08) 20050913.2711 Soybean rust, Asian strain - USA (multistate) (07) 20050909.2672 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 - USA (GA) 20050505.1245 Soybean rust, Asian strain - USA (GA) 20050429.1196 Soybean rust, Asian strain - USA (FL): 1st report 2005 20050309.0693]

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