Corn Blight

Asked September 15, 2016, 9:15 PM EDT

I have had a lot of success with corn over the years but have had a disaster this year. I used a hybrid super sweet but don't remember the name. I'll attach a photo. I live in an area that has tropical rain patterns - warm days with afternoon showers. I'd appreciate the identification of the problem and what I need to do to rectify this next season. Thanks!

Washington County Oregon corn plant disease horticulture

1 Response

Thanks for your question and photos regarding corn blight. There are several Pacific NW fungal diseases with symptoms shown in your photos; Northern Corn Leaf Blight, Northern Corn Leaf Spot and Gray Leaf Spot. In each disease, symptoms are long circular to elliptical, grayish green or tan lesions. In moist weather, dark rights may appear. Lower leaves are affected first and the disease moves up the plant with the plant's premature death resembling frost or drought injury. These fungi overwinter on infected plant debris and winds can move spores long distances. Moderate temperatures and high humidity favor the disease. Going forward: remove all infected plant debris, either bag up or bury the debris - the spores will overwinter on debris; use resistant corn varieties and hybrids, the most tolerant hybrids are late maturing; manage irrigation to avoid long periods of high humidity - do not overhead water; practice crop rotation and select seed planting sites and dates to take optimum advantage of warm soils and do not over water in first few weeks after planting.