Doane Daily Cotton Commentary

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Staff Report

August 18, 2008 - Asian soybean rust (ASR) was found today in a field study at a private ag research farm in Tift County, according to a report posted on USDA’s soybean rust web site.

“At this time, random samples are being collected to determine true incidence of rust in the field,” according to the report. “However, the severity on symptomatic leaves brought to the lab was about 10% affected leaf area.”

The report said that the find was brought to the attention of University of Georgia personnel by Dr. Larry Newsome with BASF.

ASR also was detected on 1 leaf out of 43 kudzu leaves sampled at a sentinel monitoring plot just over the Georgia-Florida border in Grady County, Georgia, on Georgia 319. “Severity was 1%. Leaves were sampled on August 11 and analyzed on August 15,” according to the notice. “This is the first find for soybean rust in Georgia in 2008 outside of a private research farm in Brooks County earlier in the season.”

ASR has been very slow to develop in Georgia in 2008. However, “conditions are now excellent for the disease to progress quickly,” the report continued. “We have plenty of moisture in the state. Much of the commercial crop is at a vulnerable reproductive stage. The disease is finally beginning to spread in Georgia, and there is the imminent threat of tropical storm Fay moving spores from Florida into production areas of Georgia.”

“For these reasons, soybean producers who a) have had plenty of moisture and/or are in the path of TS Fay, b) have beans in reproductive growth, and c) have not applied a fungicide spray in the past 12 days or so should strongly consider protecting their crop with a fungicide now. Because of rains, many growers may not be able to spray until after their fields dry. These growers should consider using a fungicide with curative activity or a protectant/curative fungicide tank-mix in their application after the storm passes.”