By Scout Nelson
Tar spot has made an early appearance this year in four northeast Kansas counties. According to Kansas State University plant pathologist Rodrigo Onofre, the counties affected—Doniphan, Atchison, Jefferson, and Nemaha—are facing the disease about a month earlier than usual.
“Now is the time to intensify scouting efforts,” advised Onofre, emphasizing the urgency to monitor fields closely due to the disease's potential impact on crop yields.
Early detection is crucial as it has historically been linked to high yield losses. "The early onset of disease that we’re observing this year raises concerns about yield loss," he noted.
Tar spot presents as small, black, raised spots on corn leaves, sheaths, and husks, which can be mistaken for insect droppings. Onofre suggests a simple test to distinguish the disease: "Sometimes, the spots may be confused with insect poop, but scraping the spot is an easy test to differentiate between a tar spot lesion and droppings."
Effective management of tar spot involves well-timed fungicide applications. “Research has shown that the best return on investment from a fungicide application on corn occurs when fungal diseases are active in the corn canopy,” Onofre explained.
For optimal results, fungicides should be applied when the corn reaches the V10-VT growth stages, with a potential second application between the R1-R3 stages if the disease persists.
Scouting for tar spot is not just a local concern; the disease has also been identified in neighboring states such as Nebraska, Iowa, and Missouri, as well as in Indiana. Careful monitoring and timely interventions are key to managing this disease effectively and minimizing its impact on corn production.
Photo Credit -gettyimages-awakr10
Categories: Kansas, Crops, Corn