September 16, 2008 - Tuesday
Rust detected in Jefferson County
Soybean rust was detected this afternoon in Jefferson County, MS. Extremely low levels of rust were detected in a soybean field at the R4 growth stage. Three leaves on one trifoliate were found to each contain a single lesion with three to four pustules each. This is much less than 1% of the leaf surface area infected by the disease. Surveys of adjacent fields did not produce anymore rust.
Even though we have now confirmed soybean rust on younger soybeans (younger than R7-R8) we are NOT suggesting/recommending a blanket fungicide application simply for the purposes of controlling soybean rust. The vast majority of the soybean acres throughout MS are out of the woods at this point as they are R5.5 and beyond.
This particular R4 soybean field was planted behind the spring flood and there are many ranges of soybean ages in this area. However, we will continue to be scouting on Wednesday to determine the extent of our young soybeans and keep you posted as the situation develops. The R4 soybean field had NOT received a R3-R4 fungicide application. We did suggest a fungicide be applied due to the presence of rust in this field.
Please keep in mind that we will continue to turn counties "red" on www.sbrusa.net. This is simply a function of the grant that we are working collaboratively on with the rest of the states in the U.S. I will do everything I can to make you aware of the situation and what growth stage the soybeans are when and if we find more rust in the coming weeks. Please monitor the hotline for any significant changes (866-641-1847) or feel free to contact me with any specific questions.