By Becky Wiepz and Dan Kielar
Station Updates
- Bloom is starting slowly throughout the county, incoming cold may slow down progress.
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 5/14 | 2021 | 2022 | 2023 | 2024 | 2025 | 20-year avg. |
| Base 50 | 136 | 136 | 163 | 219 | 156 | 152 |
Recent Weather at Peninsular Ag Research Station
| Date | Max Temp(℉) | Min Temp(℉) | Max Wind Gust(mph) | Daily Rain Total(in) |
|---|---|---|---|---|
| 5/9 | 62.8 | 33.3 | 14.5 | 0.0 |
| 5/10 | 61.9 | 41.2 | 27.3 | 0.0 |
| 5/11 | 65.8 | 32.5 | 23.3 | 0.0 |
| 5/12 | 72.5 | 49.6 | 15.0 | 0.0 |
| 5/13 | 72.9 | 51.6 | 14.5 | 0.0 |
| 5/14 | 71.6 | 55.2 | 12.8 | 0.0 |
If you’d like to see weather data for your area, visit https://wisconet.wisc.edu/
Apples
Growth Stage: Tight Cluster to Pink
Seasonal Update: Copper and Micronutrient applications should be complete. Late Copper applications can cause fruit russetting. 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 | Moths Caught | Peak Flight |
| Tarnished Plant Bug | Adults Caught | Adults Caught | Adults Caught | |
| Spotted Tentiform Leafminer | Present | Present | Present | Start of Flight |
| Codling Moth | No Catch | No Catch | No Catch | |
| Blossom Feeders/Lepidoptera | Low Pressure | Low Pressure | Low Pressure |
| Disease | Southern Door | Central Door | Northern Door | Notes |
|---|---|---|---|---|
| Apple Scab | Medium Risk | Medium Risk | Low Risk | Increased risk with increased leaf surface and rain. Check Apple Scab models on NEWA to time spray applications. |
| Fire Blight | Low Risk | No Risk | No Risk | Warm temperatures can lead to spread and growth of fireblight bacteria. When blossoms are open, protective sprays should be used. |
Cherries
Growth Stage: 25% to Full Bloom
Seasonal Update: Southern door had minimal flower bud loss due to winter damage with percentages increasing as you move north. Copper applications should be complete now.
| Pest | Southern Door | Central Door | Northern Door | Notes |
|---|---|---|---|---|
| Disease | Southern Door | Central Door | Northern Door | Notes |
|---|---|---|---|---|
| Cherry Leaf Spot | Low Risk | Low Risk | No Risk | Risk increases with leaf area expansion |
GRAPES
Growth Stage: Bud Swell
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 |
|---|---|---|---|---|