Asian soybean rust has been found in southwest Arkansas’ Little River County.
“We found it in the southeast corner of the county, about 25 miles northwest of Texarkana, Ark., and 10 miles east of Ogden,” says Cliff Coker, Arkansas Extension plant pathologist. “We only found it yesterday (July 22) and had it under a microscope this morning.”
The rust was at very low levels and was low in the canopy on new leaves.
Coker and colleagues also checked Miller County and Lafayette County and found no rust. However, they did find additional ASR just across the border north of Hooks, Texas, in Bowie County.
“A farmer alerted us to a possible find there and we checked it out. That should give an indication on how quickly word of mouth is on this. That Hooks field was sprayed with a fungicide yesterday.”
Jeremy Ross, Arkansas Extension plant pathologist, says the find “is certainly of concern. Wheat-beans could be especially vulnerable. We’re not recommending any spraying prior to R-1. Earlier than that is pointless and farmers could be looking at multiple applications. The window for application is R-1 to R-6.”
And, at this time, the fungicide recommendation is only for soybeans in southwest Arkansas. “Soybeans from west of El Dorado, Ark., to the Louisiana, Texas and Oklahoma lines at R-1 to R-6 (flowering to pod-fill) should receive a combination of strobilurin and triazole fungicides,” says Coker. “The recommendation is for both a curative and a preventative.
“Farmers in the rest of the state should hold off. As we’ve done all season, we’ll continue to scout all over and quickly let everyone know if we find anything of concern.”
The immediate plan, says Ross, is to scout southwest Arkansas heavily “and then spread out from there. I expect the Arkansas River Valley to have a bunch of scouts this week. Hopefully, the rust hasn’t spread.”