New Tools for Crop Disease Prediction

The decision to apply a fungicide to your crop depends on so many factors: varieties, growth stages, weather, application costs, and commodity prices, to name just a few. Any help we can get with that decision may bring us closer to profitability and healthy plants. We now have access to a new crop risk tool that combines the risk models for several diseases and crops into one convenient website at Crop Protection Network.

We recommend viewing information about the tool and a video tutorial to familiarize yourself with the available features. Based on our experiences, here are some key points to consider as you incorporate these into your management.

• Visit the tool early and often. These tools make their predictions based on weather information gathered from sources closest to your fields. Summer weather conditions can vary dramatically among fields, even in the same town. Be sure to run the predictor for each field you are concerned about.
• Know your crop's growth stage. These models do not know if your crop has just emerged, is flowering, or is mature. You need to integrate this information to maximize the value of using a prediction tool. For instance, soybeans at R5 or later are not very susceptible to frogeye leaf spot because the fungus is better at infecting young, expanding leaves. There is also only a minimal impact on yield. So, if the frogeye leaf spot model predicts high risk, but your beans are already at R6, this risk does not apply to you.
• Know your farm's history. Some pathogens do not move around easily from farm to farm. The pathogen that causes white mold of soybean, for instance, tends to be more readily transported in soil than over long distances in air. If your soybean field does not have a previous history of white mold infection, the pathogen may not even be present, and therefore, a high-risk prediction may not be valid for that field.
• The tool provides additional information about the diseases, as well as the weather data used to generate the predictions. Click around to see what is most useful to you. There are options to save files, which is valuable to build knowledge over time about how the different model factors react to year-to-year conditions.

For most of Pennsylvania corn this week, the risk of gray leaf spot is high, while tar spot risk remains low. For freshly silking corn, the risk of Gibberella ear rot infection and subsequent vomitoxin (deoxynivalenol, DON) is moderate in the eastern to northeastern section of the state. For beans, white mold risk is low but increasing through next week, and frogeye leaf spot is moderate to high for most areas.

While these tools have been developed and tested in midwestern states, we are looking forward to learning how well they work for the Northeast and Mid-Atlantic regions. Your feedback is welcome as we test and validate these tools as part of our operations this season.