Update to NEWA Fire Blight Model – Streptomycin applications 5 days in the future
Anna Wallis, Kerik Cox, and Dan Olmstead
The timing of streptomycin application(s) during bloom is critical for fire blight management. This antibiotic has 24-hour pre and post activity, meaning it will protect open flowers open approximately one day before and after the application is made. It can be difficult to choose the best time and/or make time for multiple applications during fire blight infection events. This is particularly true for multiple consecutive infection events or prolonged high-risk periods. It is also critical to minimize antibiotic use to prevent the development of antibiotic resistance in the pathogen population.
To help guide streptomycin applications, the NEWA Fire Blight Model has been updated to visualize the effects of streptomycin application up to 5 days in the future. To determine the optimal timing for an application, take the following steps:
- Navigate to the NEWA Fire Blight Model
- Select your Station or a nearby station
- Set Orchard Blight History
- Set the First Blossom Open Date. Choose the date that first blossoms were open in your orchard. If flowers are still open in your orchard and the model is not saying this, you may move this date later in the season to tell the model that flowers are still open.
- Observe model output for the predicted infection risk
- NEW: Set your Streptomycin Spray Date
- Adjust streptomycin application timing and view the predicted infection risk
- Select your preferred application timing based on the outputs
Example: Geneva, NY Cornell AgriTech, 5/2/2024.
Over the next few days, an elevated risk of infection is predicted by the models. Below are screenshots of the model outputs with different streptomycin timings. Without an application, there is a high risk from Wednesday through Friday (5/3-6). Applying today on 5/2 reduces the risk. An application made yesterday on 5/1 does not do much to reduce risk. Applying tomorrow on 5/3 is the best opportunity for reducing risk. Applications made any further in the future do not significantly reduce risk.
For more information and recommendations about fire blight management in 2024, you can visit Kerik Cox’s Blog: https://blogs.cornell.edu/coxlab/ and the Fire Blight Resources on the Cornell Fruit Resources page https://blogs.cornell.edu/treefruit/ipm/diseases/#Fireblight.
Figure 1. NEWA Fire Blight Model outputs for Geneva, NY on 5/2/2024. Streptomycin spray date has been adjusted for ‘No application’ (first panel), today (second panel), and tomorrow (third panel). The output indicates that application Wednesday 5/3 would be the optimal timing for most reduced risk.
