June 12, 2026


    By Becky Wiepz and Dan Kielar

    Station Updates

    • Season is starting strong, despite spring frosts, the crops are looking good.

    UW Madison/Extension Updates


    Historic Growing Degree Day Comparison

    Date 6/112022202320242025202620-year avg.
    Base 50364492.5500394.5468437
    GDD50 is 1-2 days ahead of the 20-year average.

    Recent Weather at Peninsular Ag Research Station

    DateMax Temp(℉)Min Temp(℉)Max Wind Gust(mph)Daily Rain Total(in)
    6/577.257.726.60.50
    6/678.157.014.50.01
    6/771.650.911.60.0
    6/877.957.215.00.0
    6/975.060.814.50.08
    6/1070.257.922.81.12
    6/1180.157.921.00.21
    6/1277.459.222.10.0
    Upcoming forecast will result in continued infection periods for fungal and bacterial pathogens due to predicted rain events and warm temperatures.
    If you’d like to see weather data for your area, visit https://wisconet.wisc.edu/

    Apples

    Growth Stage: Early fruit set.
    Seasonal Update: Last applications of chemical thinning should be done now or hand thinning will be the only remaining option.

    PestSouthern DoorCentral DoorNorthern DoorNotes
    Borer speciesPresentPresentPresent
    Codling MothAll blocks past biofixAll blocks past biofixAll blocks past biofix1st generation sprays should go out with a follow-up spray 10-14 days later
    Plum CurculioNo scarring observed yetNo scarring observed yetNo scarring observed yetControls should go out this week and in the following cover
    Leaf rollersFull flightFull flightFull flightRed banded leaf rollers coming to an end and oblique banded leaf rollers at peak flight
    For more information visit the NEWA Codling Moth Model.
    DiseaseSouthern DoorCentral DoorNorthern DoorNotes
    Apple ScabNone DetectedNone DetectedNone DetectedCheck Apple Scab models
    on NEWA to time spray applications based on forecasts.
    Fire BlightYesNone DetectedNone DetectedOrchards should be monitored and strikes should be removed promptly,
    cutting 12-18 inches past the end of the canker.
    Powdery MildewYesNone DetectedYesMore pressure with hot and humid weather
    in the forecast.

    Cherries

    Growth Stage: Fruit is out of the shuck.
    Seasonal Update: Pro-Gibb application to encourage return bloom should be applied 14-28 days after full bloom.

    PestSouthern DoorCentral DoorNorthern DoorNotes
    Spotted Wing DrosophilaYesYesYesFruit is not vulnerable yet but models should be utilized to time insecticide as soon as necessary since adults are present throughout the county. When possible, save effective chemistries for SWD applications closer to harvest.
    Plum CurculioNone DetectedNone DetectedNone DetectedScout for egg laying scars on fruit, especially near wooded areas.
    Borer speciesAdults CaughtAdults CaughtAdults CaughtTargeted sprays should go out 7-10 days after first catch followed by a second application 10-14 days later.
    European Red MitesScouting starts soon to monitor population build up.
    DiseaseSouthern DoorCentral DoorNorthern DoorNotes
    Cherry Leaf SpotNone DetectedNone DetectedYesEarly season dry weather has kept pressure minimal but risk is increasing with leaf
    expansion and rain events.
    Powdery MildewNone DetectedNone DetectedNone DetectedEarly season dry weather has kept pressure minimal but more pressure is expected with hot and humid weather
    in the forecast.
    Visit the Wisconet Pest & Disease Models page to check Cherry Leaf Spot for a weather station near you.

    GRAPES

    Growth Stage: E-L Growth Stage 18
    Seasonal Update: Fungicides should be applied around bloom to protect your fruit through harvest.

    PestStationNotes
    Leaf HoppersYes
    Phylloxera Some galls observed
    Red Banded Leaf RollersYes
    DiseaseStationNotes
    Black RotSingle Lesions ObservedEarly season fungal control is critical to prevent diseases from reaching
    economically damaging levels.
    Powdery MildewNone DetectedRisk will increase with current heat and humidity. Scout your orchard to determine local pressure.
    Downey MildewNone DetectedRisk will increase with current heat and humidity. Scout your orchard to determine local pressure.

    Additional Resources