By Alyssa Collins
Here are some tools you can use to make decisions on disease issues during this growing season.
Forecasting Fusarium Head Blight (Wheat Scab) in Wheat and Barley
Many of you who have been growing wheat and barley in the last few years are aware of the serious yield, quality and toxin issues associated with the disease called head scab. Managing this disease requires a multi-pronged approach, which I will review in an upcoming Field Crop News article. But one critical thing you can do is monitor the weather situation as your crop approaches flowering.
One tool available to help with this is the Fusarium Risk Assessment Tool. This is an online forecasting program that allows you to choose your state and enter a few more bits of information. In return, it will provide an infection risk prediction for your area and situation. This prediction can help you determine if you need to spray your wheat during flowering.
In recent years, it seemed like this tool didn’t reflect what we were seeing in the field as farmers—we were getting a lot of “scab-conducive” weather even though the model didn’t indicate we were at risk. With this feedback and a lot of collected data, a new model for 2015 has been developed. Erick DeWolf (extension plant pathologist, Kansas State) has been leading the effort to improve this tool. DeWolf says, “We have looked at a lot of data during the development and testing of the model. This information suggests that the new model will be a step forward in accuracy particularly for the winter wheat region. As some of you may recall, the old winter wheat model had a tendency to underestimate the risk of disease in some environments. In general, we believe the new model will be more responsive to favorable weather than the previous winter wheat model. The model is very similar to the previous spring wheat model and folks in this region may notice only minor differences.”
One of the new features is the ability to select your wheat variety’s level of resistance to scab. For instance, if you are growing a highly scab-susceptible variety, you can tell the model this and the risk assessment it provides for you will be much more aggressive. Another change is the use of weather data for the 15 days leading up to flowering—this expands the window and includes more data than before.
No models are perfect, but we are always working to improve this one. So, once we get through July, if you have some feedback about how this model worked (or didn’t work) for your crop this year, please let me know!
New Publication available from Extension: Identifying Wheat Diseases Affecting Heads and Grain
A multi-state committee of plant pathologists has created an easy-to-use, color guide for identifying head and grain diseases of wheat. These will be available through your extension educator and at certain field days. Pick up one of these useful guides next time you’re at a Penn State event.
While this guide is not yet available as a PDF online, some of the same information and great color photos are available in this Wheat Disease Identification publication found here.
New fungicide efficacy tables available for corn and soybeans
Each year, plant pathologists from across the nation perform hundreds of fungicide tests in the field. The results of these studies and those from previous years are then combined and turned into a concise, useful chart with is available for all of us to use during the next season.
You might find it helpful to print out these charts to keep on hand if you need to make some fungicide decisions for corn or beans this year. These are also available through your extension office and in the PSU Agronomy Guide.
Source: psu.edu