The 2019 growing season was favorable to diseases in our corn and soybean production systems. In southwest NY, Northern Corn Leaf Blight (NCLB) and Grey Leaf Spot (GLS) showed up and spread throughout our corn fields. Northern corn leaf blight fungus survives the winter on infected corn residue and remains on the soil surface. As temperatures increase in the spring, the fungus produces spores which then splash or are wind-blown onto the lower canopy of the corn plants. Last year, the cool, wet summer allowed for early appearance in our corn fields. Grey leaf spot is a destructive disease that can significantly reduce yields. Just like NCLB, the disease survives on corn residue on the soil surface and splash from the soil surface onto the lower leaves of a corn plant. The wind can carry the spores to a neighboring field if the disease is present in the crop residue. These two diseases can result in 10-50% yield reductions if the timing and conditions are favorable. Weather is the primary influence on the development of these diseases, but proper management with hybrid selection and use of an in-season fungicide will help limit the exposure to these diseases. Contact your local extension specialist for correct identification and management of these pests!

For more information see: https://www.extension.purdue.edu/extmedia/BP/BP-56-W.pdf;

https://www.extension.purdue.edu/extmedia/BP/BP-84-W.pdf