CURRENT TEXAS SITUATION: July 18, 2008
No rust has been found in any of the soybean production areas of Texas to date, including the Lower Rio Grande Valley. Rust is still confined to one kudzu patch in East Texas. Since one month ago, the amount of rust in this patch has actually DECREASED. How can this be? Severely-infected leaves have defoliated, while much of the newer growth has not become infected. Hot, dry conditions have slowed disease progression in this patch. Additionally, other kudzu patches in the vicinity (40 feet to ½ mile distant) still do not have rust.
Photos:- * Symptoms of downy mildew on a soybean leaf. This disease will not cause losses to soybeans in Texas
- * Symptoms of Asian soybean rust (red arrow) found on soybean from the Lower Rio Grande Valley of Texas. in 2007. Note extensive mite damage (white specks).
- * Symptoms of Asian soybean rust (red arrow) on soybean from the Lower Rio Grande Valley of Texas in 2007.
PROGNOSIS:
Dry conditions throughout most of state will not favor establishment or increase of this disease. The risk of economically-damaging levels of rust is very low. Many fields in the southern part of the state have advanced sufficiently in maturity that if rust were introduced into them, there would be no economical impact.
RECOMMENDATIONS:
There are no preventative fungicide spray recommendations at this time. Keep scouting. Send suspicious leaves to our lab for confirmation of rust.
CONTACTS FOR INFORMATION AND DIAGNOSIS:
Samples should be submitted for diagnosis to your local county agent or to Texas Plant Disease Diagnostic Laboratory, particularly if the plant is something other than soybean or kudzu.
TPDDL, 1500 Research Parkway, Suite A130
Texas A&M University Research Park
College Station, Texas USA 77845
Phone: (979) 845-8032 Fax: (979) 845-6499
SYMPTOMS More | Photo Archives
This is not soybean rust! It looks like it, except that it lacks the raised pustules that would be visible with magnification. It is probably a mineral deficiency. If you are unsure whether you have soybean rust, hold off spraying until you receive a diagnosis through our lab. With very dry conditions throughout much of the state, such rust-like symptoms may be common. This leaf was collected from Burleson County, June 8, 2008.
SENTINEL PLOTS AND SURVEYS:
Sentinel plots are located in soybean production areas throughout the state. Additionally, ad hoc surveys are made of commercial fields and kudzu patches. The map below shows the only location of soybean rust known in Texas, on a kudzu patch in Livingston, in Polk County.
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