By Becky Wiepz and Dan Kielar
Station Updates
- Mulching of orchards and vineyards is in progress.
- Orchard planting was completed this week.
UW Madison/Extension Updates
- Note to Grape Growers: Unusual Vine Dieback Observed This Spring
- Take Steps To Ensure That You’re Complying With the EPA Herbicide Strategy To Protect Threatened and Endangered Species
- Managing Phomopsis Cane and Leaf Spot in Wisconsin Vineyards
- Apple Powdery Mildew in Wisconsin Orchards: What You Should Know
- Apple Fire Blight Shoot Blight Management for Wisconsin Growers
- Wisconsin Fruit Crop Scouting Report: June 4, 2025
Historic Growing Degree Day Comparison
| Date 6/5 | 2021 | 2022 | 2023 | 2024 | 2025 | 20-year avg. |
| Base 50 | 395.5 | 309 | 430.5 | 433 | 321 | 360 |
Recent Weather at Peninsular Ag Research Station
| Date | Max Temp(℉) | Min Temp(℉) | Max Wind Gust(mph) | Daily Rain Total(in) |
|---|---|---|---|---|
| 5/29 | 70.0 | 51.1 | 16.8 | 0.09 |
| 5/30 | 68.9 | 48.4 | 19.5 | 0.0 |
| 5/31 | 63.7 | 41.7 | 15.7 | 0.0 |
| 6/1 | 64.2 | 38.5 | 13.4 | 0.0 |
| 6/2 | 77.5 | 49.3 | 20.6 | 0.0 |
| 6/3 | 73.6 | 55.9 | 21.0 | 0.07 |
| 6/4 | 70.3 | 55.8 | 16.1 | 0.13 |
| 6/5 | 74.5 | 48.4 | 11.6 | 0.0 |
If you’d like to see weather data for your area, visit https://wisconet.wisc.edu/
Apples
Growth Stage: Petal Fall
Seasonal Update: Avoid Insecticide Application when blooms are open to protect pollinators. Lime sulfur sprays need to be applied during bloom to impact crop load. After petal fall, plant growth regulators can be used to remove additional fruitlets.
| Pest | Southern Door | Central Door | Northern Door | Notes |
|---|---|---|---|---|
| Tarnished Plant Bug | None Caught | 1 Caught | Appears to be a break in movement | |
| Spotted Tentiform Leafminer | Present | Present | Present | Flight continues |
| Codling Moth | Adults Caught | None Caught | Adults Caught | Flight continues *see caption below |
| Blossom Feeders/Lepidoptera | Low Pressure | Low Pressure | Low Pressure | |
| Oriental Fruit Moth | Adults Caught | Adults Caught | No Catch | Start of Flight |
| Disease | Southern Door | Central Door | Northern Door | Notes |
|---|---|---|---|---|
| Apple Scab | Medium Risk | Medium Risk | Medium Risk | Increased risk with increased leaf surface and rain. Check Apple Scab models on NEWA to time spray applications. |
| Fire Blight | Medium to High Risk | Low Risk | Low Risk | Infection only possible while blossoms are open. |
Cherries
Growth Stage: Approaching Shuck Split
Seasonal Update: Fungicide should be applied before rain events now that bract leaves are open. Once fruit is out of the shuck, insecticide should be applied for Plum Curculio.
| Pest | Southern Door | Central Door | Northern Door | Notes |
|---|---|---|---|---|
| Plum Curculio | Fruit is not at risk of PC damage until after shuck split |
| Disease | Southern Door | Central Door | Northern Door | Notes |
|---|---|---|---|---|
| Cherry Leaf Spot | Low Risk | Low Risk | Low Risk | Risk increases with leaf area expansion and rain events |
GRAPES
Growth Stage: E-L Growth Stage 12-13
Seasonal Update: Pre-Bloom fungicide should be applied soon, as appropriate for your cultivar. Shoots should be thinned to ~2 per spur while shoots are still short.
| Pest | Southern Door | Central Door | Northern Door | Notes |
|---|---|---|---|---|
| Flea Beetles | Low risk | Low risk | Low risk | Spring damage on swelling buds is the only feeding that poses economic risk. |
| Disease | Station | Notes |
|---|---|---|
| Grape Phomopsis | None observed | |
| Phylloxera | None observed | monitor plants for galls on leaf undersides |