By Becky Wiepz and Dan Kielar
Station Updates
- The season is starting slowly with all crops working towards bloom.
- Pruning should be complete in all crops.
- Sprayers should be calibrated and spray data programs should be assembled for the year.
UW Madison/Extension Updates
- EPA has launched a new system to communicate additional use limitations to protect endangered species and their habitat
- Apple Crop Load Management Starts Now: Tips for Bloom Thinning
- New Frost/Freeze Forecast Tool Now Available for Wisconsin Fruit Growers
- Fertilizing Wine Grapes: Linking Shoot Growth to Petiole Nitrogen
- Wisconsin Fruit Crop Scouting Report: May 7, 2025
- Notes from the Field: A Growers Perspective – Ben Kraus Chat #2
- Wisconsin Orchard Update: Fire Blight Management
- UW-Madison/Extension Insect Diagnostic Lab Update – May 8, 2025
- Mustang Maxx Label Updated to 3day PHI for tart cherries
- Chlorpyrifos (lorsban) is not allowed on any fruit crops in Wisconsin
Historic Growing Degree Day Comparison
| Date 5/8 | 2021 | 2022 | 2023 | 2024 | 2025 | 20-year avg. |
| Base 50 | 112 | 57.5 | 108 | 182.5 | 98 | 122 |
Recent Weather at Peninsular Ag Research Station
| Date | Max Temp(℉) | Min Temp(℉) | Max Wind Gust(mph) | Daily Rain Total(in) |
|---|---|---|---|---|
| 5/3 | 50.0 | 33.8 | 14.5 | 0.0 |
| 5/4 | 63.1 | 32.5 | 21.0 | 0.0 |
| 5/5 | 61.7 | 46.4 | 13.9 | 0.0 |
| 5/6 | 69.8 | 48.2 | 14.5 | 0.0 |
| 5/7 | 56.7 | 39.9 | 27.3 | 0.0 |
| 5/8 | 51.6 | 37.0 | 17.2 | 0.0 |
If you’d like to see weather data for your area, visit https://wisconet.wisc.edu/
Apples
Growth Stage: Green Tip to Tight Cluster
Seasonal Update: Copper and Micronutrient applications at Green Tip. Possible insecticide application at Pink for Green Fruit Worm and other Lepidoptera. Early season oil applications for mite and scale pressure if present in your orchard.
| Pest | Southern Door | Central Door | Northern Door | Notes |
|---|---|---|---|---|
| Green Fruit Worm | Moths Caught | Moths Caught | No Catch | |
| Tarnished Plant Bug | No Catch | Adults Caught | No Catch | |
| Disease | Southern Door | Central Door | Northern Door | Notes |
|---|---|---|---|---|
| Apple Scab | Medium Risk | Medium Risk | Low Risk | Increased risk with increased leaf surface. Check Apple Scab models on NEWA to time spray applications. |
Cherries
Growth Stage: Green Tip in tart cherries
Seasonal Update: Southern door had minimal flower bud loss due to winter damage with percentages increasing as you move north. Copper applications can go out for bacterial canker.
| Pest | Southern Door | Central Door | Northern Door | Notes |
|---|---|---|---|---|
| Disease | Southern Door | Central Door | Northern Door | Notes |
|---|---|---|---|---|
| Cherry Leaf Spot | no risk | no risk | no risk | Risk begins once bract leaves are open |
GRAPES
Growth Stage: Wooly bud
Seasonal Update: Budburst is likely to occur quickly with incoming warm weather.
| Pest | Southern Door | Central Door | Northern Door | Notes |
|---|---|---|---|---|
| Flea Beetles | Low risk | Low risk | Low risk | Increasing risk as temperatures climb |
| Disease | Southern Door | Central Door | Northern Door | Notes |
|---|---|---|---|---|