Sheath blight is being found in some Arkansas cornfields.

“We started picking this up about three weeks ago,” said Scott Monfort, Arkansas Extension plant pathologist, on July 7. “It isn’t a widespread issue — it’s scattered around the state and doing some damage here and there.”

Corn hit with the disease is usually planted behind rice. However, that isn’t the case everywhere.

“One of the cornfields we found it in is in the Arkansas River Valley and was planted behind soybeans.”

As for treatment on affected fields, “if a producer is already spraying, it would probably be good idea to add a strobilurin fungicide to the mix. And increase the water volume.”

Getting the treatment “down into the plant where it needs to be can be tough. Right now, we’re not even getting the fungicides we need to control Southern rust down into the canopy. Gaining control may be hard but without treatment it could cause more problems. Some producers are trying Quadris at higher rates — or Quadris at recommended rates with 8 to 10 gallons of water.”

Monfort also warned that Southern rust is continuing to increase in the state’s corn. “More people are finding it and more and more acres are being treated. There’s still a lot of corn vulnerable to Southern rust. If there’s any question about a crop’s level of vulnerability, the grower needs to be out there scouting for it.”

e-mail: dbennett@farmpress.com