At the end of June there had been very little change in the development and spread of soybean rust from the previous week in Louisiana and Texas.
The most active location of soybean rust to date is in Florida where rust is continuing to develop on kudzu. The increased development of soybean rust in Florida compared to Louisiana and Texas can be contributed to the optimum environmental conditions (cloudy and rainy) in Florida over the last few weeks.
Soybean rust in Texas and Louisiana remains active but does not seem to be spreading outside of the small kudzu patches reported on June 4. The active kudzu patches are in Iberia Parish, La., and Polk County, Texas. The slow development and spread of soybean rust can be contributed to the lack of rain and cloudy weather in Texas and Louisiana over the last few weeks.
We are continuing to scout kudzu patches, soybean sentinel plots, and soybean fields throughout Arkansas. We currently have an estimated 10 to 15 percent of the soybean crop in the reproductive stages. With this in mind, I ask county agents with soybean sentinel plots and/or kudzu patches to continue to send in samples to the diagnostic lab at Lonoke.
I am thankful for the county agents that have sent in samples thus far.
I also encourage consultants and growers to send in kudzu and/or soybean samples (at least 100 leaves) during the season if they think they have soybean rust.
There are a few changes to the list of available fungicides for soybean rust control for 2008.
Some of the fungicides — Alto, for example — have rotation restrictions, and some of the fungicides (Folicur, Caramba, etc.) may cause some foliar burn which can mimic SDS foliar symptoms.
Any suspicious leaves (soybean and/or kudzu) can be sent to the Lonoke Diagnostic Lab.
The Soybean Rust Hotline is continually updated with information about the latest rust finds. That number is (866) 641-1847. If you have any questions or concerns please contact me at (870) 659-0648), Jeremy Ross at (501) 944-0621), or Amy Carroll at (870) 258-2509.