June 19, 2026

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By Becky Wiepz and Dan Kielar

Station Updates

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

UW Madison/Extension Updates

• Wisconsin Fruit Crop Scouting Report: June 3, 2026
• Notes from the Field: A Grower’s Perspective – Erin Warner #3
• Apple Shoot Blight Management: What Should Wisconsin Growers Do Now?
• Petiole Sampling for Determining Fertilization Needs in Cold-Climate Grapes
• Protecting Grape Clusters During the Critical Pre-Bloom to Post-Bloom Period

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Historic Growing Degree Day Comparison

Date 6/18	2022	2023	2024	2025	2026	20-year avg.
Base 50	467.5	552	620.5	476.5	552	536

Recent Weather at Peninsular Ag Research Station

Date	Max Temp(℉)	Min Temp(℉)	Max Wind Gust(mph)	Daily Rain Total(in)
6/11	80.1	57.9	21.0	0.21
6/12	77.4	59.2	22.1	0.0
613	78.3	55.8	25.5	0.12
6/14	62.8	48.9	21.7	0.0
6/15	74.5	48.7	17.9	0.0
6/16	69.6	52.9	18.3	0.0
6/17	61.9	51.1	16.8	0.59
6/18	71.4	53.2	21.0	0.09

Apples

Growth Stage: 10-15mm fruit in most varieties
Seasonal Update: Use low rate NAA 5-6 weeks after full bloom to enhance return bloom next year. Check your label for rate information.

Pest	Southern Door	Central Door	Northern Door	Notes
Borer species	Present	Present	Present
Codling Moth	Peak flight 1st generation	Peak flight 1st generation	Peak flight 1st generation	1st generation sprays should go out with a follow-up spray 10-14 days later
Plum Curculio	No scarring observed yet	No scarring observed yet	No scarring observed yet	Controls should go be included in your second cover spray
Leaf rollers	Full flight	Full flight	Full flight	Red banded leaf rollers coming to an end and oblique banded leaf rollers at peak flight

Disease	Southern Door	Central Door	Northern Door	Notes
Apple Scab	None Detected	None Detected	None Detected	Primary spore dispersal is nearly done. If control was good, sprays can be stretched to 10-14 days between applications
Fire Blight	Yes	None Detected	None Detected	Orchards should be monitored and strikes should be removed promptly, cutting 12-18 inches past the end of the canker.
Powdery Mildew	Yes	None Detected	Yes	If present, include a product that specifies control on the label and plan on and early season application of sulfur next year.

Cherries

Growth Stage: Fruit is sizing up.
Seasonal Update: New leaves are still expanding so good fungicide coverage is essential for season long tree health. Gibberellic acid application can be used to manage return bloom when applied 14-28 days after full bloom. See the article linked below for more information.

Pest	Southern Door	Central Door	Northern Door	Notes
Spotted Wing Drosophila	Yes	Yes	Yes	Fruit 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 Curculio	Adults Detected	Adults Detected	Adults Detected	Few egg laying scars have been detected, 1 more spray should be adequate to keep larvae out of the fruit at harvest.
Borer species	Adults Caught	Adults Caught	Adults Caught	Targeted sprays should go out 7-10 days after first catch followed by a second application 10-14 days later.
European Red Mites				Scouting starts soon to monitor population build up.

Disease	Southern Door	Central Door	Northern Door	Notes
Cherry Leaf Spot	Yes	Yes	Yes	Application windows should remain tight as long as leaves are expanding and rain events continue.
Powdery Mildew	None Detected	None Detected	None Detected	If present, include a product that specifies control on the label and plan on and early season application of sulfur next year.

GRAPES

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

Pest	Station	Notes
Leaf Hoppers	Yes
Phylloxera	Some galls observed
Red Banded Leaf Rollers	Yes

Disease	Station	Notes
Black Rot	Single Lesions Observed	Early season fungal control is critical to prevent diseases from reaching economically damaging levels.
Powdery Mildew	None Detected	Risk will increase with current heat and humidity. Scout your orchard to determine local pressure.
Downey Mildew	None Detected	Risk will increase with current heat and humidity. Scout your orchard to determine local pressure.

Additional Resources

• Gibberellic Acid Applications in Cherries
• Financial Decisions for Tart Cherry Crops with Variable Yields
• Take Steps To Ensure That You’re Complying With the EPA Herbicide Strategy To Protect Threatened and Endangered Species