A field crops pathologist says while tar spot was found earlier than normal this year, the rest of the season will determine its impact as it spreads in states surrounding Lake Michigan and westward.
Marty Chilvers with Michigan State University tells Brownfield corn tar spot thrives in wet conditions and wide-sweeping rains at the end of June brought along ideal conditions through Great Lakes states.
“Fungicides are probably going to be best between R1 through about R3 growth stages typically, we sort of want to catch the disease at the start,” he explains.