This season's first cases of Asian soybean rust in Mississippi have been discovered in Wilkinson County kudzu. The state's ASR team found the disease between Fort Adams and Woodville in two locations.
“Soybeans were examined around the area, but we couldn't find any infections,” says Billy Moore, ASR team leader and Mississippi Extension plant pathologist. “The disease on the kudzu was moderate to heavy.”
Moore and colleagues called farmers throughout the surrounding area and “suggested they consider spraying a fungicide. The two finds have now triggered applications in Franklin, Amite, Adams and Wilkinson counties.”
The soybeans in those counties are at various growth stages. “We've got some at R-3/R-4, others are already at R-5. All could be subject to rust, and this is just about the right time to apply a fungicide.”
If a producer in the aforementioned counties has soybeans at R-3/R-4, “since they're in such close proximity to ASR, they should use both a strobilurin and a triazole.”
Outside that four-county area, farmers shouldn't take any action yet. “Until we're convinced ASR is moving and is a threat outside these four counties, just sit tight.
ASR spores could be moving around the Mid-South, warns Moore. “In the past month to six weeks, air currents have moved through (infected) areas and throughout the Mid-South. Add very favorable weather conditions for ASR development — moisture, cooler temperatures, thick canopies — throughout the Delta and things could change for the worse quickly. Everyone should be on the lookout for ASR in soybean fields. If anyone sees anything that could be ASR, please contact your county Extension agent.”
Over the last three weeks, there have been a “tremendous” number of rumors about ASR having been located in Mississippi. “We've chased those rumors, trying to quiet them down or confirm them. Even after all that, the four-county area is all we're concerned about.
“We're in Adams County and moving north. The team will be up around Vicksburg scouting fields before the week's done.”
Moore also encourages farmers to make use of the free ASR hotline — (866) 641-1847 — for immediate updates. “The messages are changed frequently to provide the freshest information. Farmers can hear specialists in Mississippi, Louisiana and Arkansas report on current situations and recommendations.”