MU: Tar spot coming in hot in Missouri
Tar Spot is not going away in Missouri as it continues its spread into more states.
“Tar spot is definitely coming in hot,” says Kaitlyn Bissonnette, MU Extension’s state field crop plant pathologist, at the MU Crop Management Conference. She says tar spot is confirmed in eight northeast Missouri counties but anecdotal evidence means it’s probably across the entire northern part of the state.
She says Missouri is set up for tar spot development, “Partially because we have moderate temperatures, high relative humidity, we have seven-plus hours of leaf wetness at night. And that’s going to be the biggest risk factor that we’re really dealing with.” Bissonnette says areas with irrigation – northwest, southwest, and southeastern Missouri – are susceptible to lengthy leaf wetness.
She stresses the importance of scouting and if farmers aren’t sure if it’s tar spot, common rust or southern rust, to send samples to the MU plant diagnostic clinic.
“We could, potentially, see a lot of yield loss in fields where we’re not appropriately managing so staying ahead and keeping our information up to date is going to be critical.”
Bissonnette says research is ongoing into corn hybrids and fungicides, just not in Missouri yet.
While the heaviest tar spot states are north of Missouri – it has also been found south, in Tennessee, Georgia, and Florida.