Unfortunately, there is no crystal ball that can reveal what impact disease will have on your farm. However, you can take advantage of the new web-based Crop Risk Tool hosted by the Crop Protection Network to assess disease risk.
The Crop Risk Tool forecasts the risk of multiple foliar diseases like tar spot and gray leaf spot in corn and white mold in soybean using validated disease models and site-specific weather data. Risk forecasts are updated daily based on recent weather conditions and a 7-day forecast is included to aid future decision-making
It will also soon include the vomitoxin risk forecast model being developed by the Ohio State University Cereal Pathology Lab thanks to support from the Ohio Corn Marketing Program.
Follow the steps below to use the Crop Risk Tool or view a step-by-step video at https://www.youtube.com/watch?v=xJ707vRQkjE.
Step 1: How to Access the Tool
To access, click on the green button “Access The Forecasting Tool” on the landing page https://cropprotectionnetwork.org/crop-disease-forecasting
Step 2: How to Set Up Location
Either zoom in and find the location you are interested in and drop a pin, or you can upload a prepopulated .csv file with GPS coordinates (latitude, longitude as decimal degrees in separate columns). Then click on the “Fetch Weather Data” button to retrieve GPS-specific weather conditions.
Step 3: Finding Probabilities of Risk
Select the appropriate crop and the included disease forecast models will be displayed on the righthand pane of the tool.
Step 4: Interpreting the Data
The Crop Risk Tool should only be used during periods when crops are susceptible to the disease. For example, only between growth stages V10 and R3 for corn foliar diseases. Also keep in mind that the pathogen must be present in the field along with a susceptible variety or hybrid for disease to occur.
In the example below, the forecast was restricted to the past week (July 3 – 10, 2025) and the 7-day forecast at the Northwest Agricultural Research Station in Wood County. Assuming the crops are at or past the V10 growth stage, the risk of tar spot is low, but extremely high for gray leaf spot. In this case, if corn is tasseling and/or silking and a susceptible hybrid was planted, a fungicide application should be considered to manage gray leaf spot.
The Crop Risk Tool is powered by the National Predictive Modeling Initiative of the USDA-ARS and was developed in collaboration with the University of Wisconsin-Madison Department of Entomology. Funding for individual crop disease forecasting tools was provided by the National Corn Growers Association, the North Central Soybean Research Program, and the United Soybean Board.