There are over 80 diseases described on corn worldwide (Munkvold and White, 2016). Approximately half of these diseases have been described in Iowa. Some diseases, such as gray leaf spot, northern corn leaf blight and anthracnose stalk rot have been prevalent for decades. Some diseases, such as Physoderma brown spot and Goss’s wilt, have re-emerged within the past few years. And then we have new diseases being reported such as tar spot and bacterial leaf streak.