September 15, 2005
From: Southeast Farm Press, 15 Sep 2005 [edited]
<http://southeastfarmpress.com/news/091505-Alabama-rust/>

Asian soybean rust [ASR] continues to show up in Alabama fields at low severity. Since 9 Sep 2005, there have been 2 new rust findings in the state.

"One was in a Clarke County sentinel plot near Jackson, about an hour north of Mobile," said Ed Sikora, Alabama Extension plant pathologist on 14 Sep 2005. "The plot was drying down and I found a few infected leaves low in the plant. It wasn't anything major."

The 2nd discovery was in a small commercial field in Geneva County by Slocumb. It too had ASR at low incidence/low severity.

It takes about 2 weeks after spore deposits for rust symptoms to show up. Knowing that timeline, Sikora has been keen to check north Alabama for any rust transported by Hurricane Katrina. On 13 Sep he drove into the north and northeast part of the state and checked 3 sentinel plots and a handful of commercial fields but found no signs of ASR. That doesn't mean Katrina didn't push rust spores north, cautioned Sikora. "It's sketchy trying to find rust in a commercial field in early stages. I've been pretty lucky in finding it early in some fields. I thought I might find it up there, but no." Most of the fields in north Alabama are "yellowing up" into R-7.

Many fields are being harvested. "It's also been hot and dry since Katrina passed through, so conditions haven't been favorable for rapid disease development." Is Sikora seeing any defoliation due to soybean rust?

According to Sikora, the most interesting case was one of the 1st commercial fields in Baldwin County. The grower has 50 or 60 acres he treated with Stratego about 21 days apart. He put the first fungicide on before knowing the disease was in his crop."

Sikora visited that field earlier this month. There was very little defoliation. Across the road from the main field, the producer has a one-acre soybean patch -- a different variety in the same maturity group. Unable to spray the patch, he left it as a check and the patch was hit hard by ASR. But right across the street, where he sprayed twice, the crop was protected from ASR. Sikora said that "illustrates the power of a fungicide."

[Byline: David Bennett]

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

[ProMED-mail has no direct or indirect involvement with the manufacturers of Stratego.

The anecdotal accounts in this piece illustrate the ASR situation in the States on the Gulf of Mexico. Depending upon local weather conditions, ASR spores may land on unprotected soybeans or on those recently sprayed with fungicides. Those growers who sprayed with fungicide will likely have an advantage over those who have not yet sprayed. I suggest that at this late time in the soybean production cycle, the potential for disease is dwindling. ASR may be confined to the southern US, but that doesn't mean soybean growers elsewhere in the country should forget about the disease and how to manage it.

Some of the top experts in North America have assembled a 60-page color booklet entitled "Using Foliar Fungicides to Manage Soybean Rust." It contains contributions from plant pathologists from the nation's leading land-grant universities, as well as experts from Canada. The manual is available through state extension offices or it can be downloaded chapter-by-chapter online at:
<http://www.oardc.ohio-state.edu/SoyRust/>

Link:
<http://www.agriculture.com/ag/story.jhtml?storyid=/templatedata/ag/story/data/agNews_050915crRUST.xml&catref=ag1001> 
- Mod.DH]

[see also in the archive:
Soybean rust, Asian strain - USA (FL): 1st report 2005 20050309.0693 Soybean rust, Asian strain - USA (GA) 20050429.1196 Soybean rust, Asian strain - Americas: alert 20050528.1476 Soybean rust, Asian strain - USA (GA) 20050505.1245 Soybean rust, Asian strain - USA (LA) 20050624.1769 Soybean rust, Asian strain - USA (FL) (02) 20050620.1731 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 (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 Soybean rust, Asian strain - USA (multistate) (07) 20050909.2672 Soybean rust, Asian strain - USA (GA) (04) 20050905.2623]