News

Yes, tar spot already

A plant disease researcher says conditions are right for early corn tar spot infections.

Dr. Damon Smith with the University of Wisconsin says, “A couple of my colleagues have already reported tar spot in their states. Kansas, in Doniphan County and then (Porter County) Indiana.”

Smith tells Brownfield the Indiana case is on some young corn no-till planted after corn at a research plot where there was tar spot last year.  “This cooler pattern with some of this intermittent rain is just really conducive for the pathogen so I guess it’s not entirely surprising but much earlier than folks generally seen it.”

So far, Smith says his team has not found tar spot in Wisconsin research plots, but they’re watching closely. “There was a band of tar spot kind of through the center of the state, right across the central sands region, and so we’re going to watch that pretty closely because we can assume that the innoculant potential would be higher there than maybe in some other parts of the state.”

Smith says his team’s study in 2018 showed the tar spot pathogen can survive winter easily, and he says corn-on-corn acres are the first place to start scouting.

A map showing U.S. tar spot locations is available online, along with other disease tracking maps, tools, and resources at cropprotectionnetwork.org. Maps are available under the Resources tab.

AUDIO: Dr. Damon Smith discusses the first tar spot findings with Brownfield’s Larry Lee.