Hurricanes Fay and Gustav blew Asian soybean rust northward into Arkansas, but farmers have little reason for alarm since much of the crop has matured past the point where the disease could impact it, says Scott Monfort, Arkansas Extension plant pathologist.
The storms initially pushed rust into southeast Arkansas and it was soon confirmed in six counties located in the southern half of the state. Over the past two weeks, university scouts found rust in six additional counties, crossing I-40 into northern Arkansas.
Monfort says rust infestations are at low levels, however, and it's unlikely the disease will accelerate, given the current weather and crop conditions.
A small percentage of the state's soybean fields, planted as late as July, might be affected at an economic level.
"It takes living material for rust to reproduce, so if there's green material out there, it has the potential to grow. But I'd say 97% of our acreage is now past the point where it can do anything substantial to the crop,” Monfort says.
He thinks Midwestern farmers will likely see little rust infestation the remainder of the season. "It came in late and is not going to have a major impact this year. It's not going to be a big player. We track it to let people further north from us know where it is. There's probably no reason for concern this year. It could move northward but I'd say most of the acres up north are getting close to harvest, so it shouldn't be a concern there,” Monfort says.
The hurricanes and generally wet weather contributed to disease growth in other Arkansas crops. Monfort says soybeans have been hit with aerial blight, frogeye and anthracnose. Some rice has sheath blight and quite a bit of rice blew down during the hurricanes, creating lodging problems. Some of the corn crop had a late infestation of Southern rust, particularly fields double-cropped behind wheat.
"All in all, it hasn't been an overly bad year for diseases, though,” Monfort says.