Through the first week of July, two incidences of Asian soybean rust had been found in southern Louisiana kudzu. The finds were only a few miles apart in Lafayette Parish and neighboring Iberia Parish.
While both finds were reportedly sporulating heavily, as of mid-day, July 16, no additional infection sites had been found. Most importantly, ASR has yet to be found in any Louisiana soybeans.
However, LSU AgCenter specialists say that could change quickly and are encouraging any leaves with suspicious lesions be pulled for evaluation.
“We’ve been scouting all over the area where ASR was initially found,” said David Lanclos, LSU AgCenter soybean specialist. “As we speak, there are guys searching for it. ASR just isn’t being found on soybeans.
“We’re continuing to promote vigilance. Unfortunately, we can’t scout everything, so we’re asking folks to bring in anything they think is suspect. If anyone finds something in the field that doesn’t look quite right, pull a sample and take it to your local parish agent. They’ll take it from there.”
One encouraging sign is Lanclos has yet to be brought any samples “that have amounted to anything. And I don’t think any of the other (ASR team) members have either. No additional ASR has been confirmed and by now (the team members are) confident we know what ASR looks like.”
This year, Louisiana has some 820,000 acres of soybeans. The crop, writes Lanclos in his weekly newsletter, has recently taken a “turn for the better…Most of the rain we received over the past three weeks started falling when the majority of the crop was approaching R5. Because of this…beans have filled out adequately and our crop looks very good. Some portions of the crop did not receive adequate rainfall and will be harvested in the next couple of weeks. Yield potential for the state looks excellent right now.”
Diseases have begun to show up in the crop — something that is also being reported in Mississippi soybeans.
“We are still recommending that producers continue to apply (strobilurin)-based products at R3 tank-mixed with Topsin-M for cercospera leaf blight if need be. This is our standard fungicide recommendation.”
Fungicide spraying recommendations have not changed for ASR. Any rumors from chemical companies to the contrary are untrue. According to Clayton Hollier, LSU AgCenter plant pathologist, recommendations will change if the disease is found on soybeans.
Extension personnel are encouraging Mississippi and Louisiana producers to make use of a frequently updated toll-free ASR hotline at (800) 516-0865.