Start looking for corn diseases
Farmers are encouraged to start looking for symptoms of common corn diseases.
Corteva Agriscience market development specialist Jeff Moon says tar spot, northern corn leaf blight, and gray leaf spot could be seen across a lot of geographies this season.
“There’s been a lot of discussion about tar spot the last few years, and that footprint that it’s in seems to be growing a little bit. It seems to really like cooler temperatures but with high humidity.”
He tells Brownfield a foliar disease becomes more likely the longer leaves are wet.
Moon covers Minnesota and says northern corn leaf blight typically starts on the lower canopy and does not have the dark black lesions associated with tar spot.
“I would say this is more of grayish or tan-looking lesions that develop on that corn plant, kind of an elliptical shape to them.”
He suggests gray leaf spot is unique because it likes warmer temperatures.
“And again, humidity plays a big role. Gray leaf spot, it’s kind of a long, thin, rectangular-looking lesion that forms on that corn plant.”
Moon advises farmers to scout for corn diseases at least once per week and says tar spot needs to be addressed as soon as possible because it progresses quickly once it’s established.