Hello Wisconsin Fruit News subscribers and welcome back to season 3 of Notes from the Field: A Grower’s Perspective! The goal of this series is to foster connections between fruit crop growers during the growing season. Last season we heard from Philippe Coquard, wine maker and grape grower at Wollersheim Winery in Prairie Du Sac, Wisconsin. If you missed us last season, check out our conversations here.

As we enter the third season of this newsletter series, we have decided to highlight an organic fruit grower in Wisconsin… drum roll please… Chris McGuire, grower and owner of the Blue Roof Orchard in Belmont, Wisconsin. Chris has been farming for over 20 years and has been growing organic apples since 2012. Chris has also been very active in conducting on-farm research on various fruit crops including apples and gooseberries. Summaries of his various research projects can be found here.

Chris and I had our first chat of the season on April 30…

Spring has brought both challenges and opportunities for orchard management, with peak bloom occurring earlier than usual but not as early as initially feared by many growers with the mild winter temperatures. The earliest varieties have started petal fall, while late varieties are just beginning to bloom.

Chris is in the process of planting new trees this year, but the progress has been slowed down by frequent rain showers. Today at Blue Rood Orchard, a critical task involved notching above dormant buds to stimulate branching, a vital practice for encouraging lateral bud growth. There are notable distinctions in tree canopy growth regulation approaches between non-organic and organic growers. While non-organic methods can utilize growth regulators, organic orchards rely solely on notching to induce branching, which helps prevent the formation of blind wood on the leader. This practice is considered highly valuable for organic growers.

Fungicidal and bactericidal sprays in mature trees are focused on combating scab and fire blight with the recent wet weather. Chris utilizes several OMRI (Organic Materials Review Institute) listed products including Carb-o-nator (potassium bicarbonate), Sil-Matrix (potassium silicate), Regalia, Serenade, and Cinnerate. When application windows are limited due to rainy and windy conditions, Blossom Protect, a yeast-based biocontrol product, is not ideal for tank mixing or close rotations with some of the other products Chris is applying.

In Wisconsin, the bloom period is unfolding at a slower pace compared to previous years with warmer temperatures; the cooler weather has contributed to this delay. As the bloom advances, Chris highlights the dual advantages of applying high doses of potassium bicarbonate: effective control of fungal diseases and bloom-thinning effects. It’s crucial to time these applications when trees are experiencing heavy flowering while lighter bloom varieties may require only one spray at 70-80% bloom.

There is not much in the way of insect pest concerns currently, but a delayed dormant oil was applied to control aphids, scales, and mites. Weed control measures are also underway, focusing on preventing weed migration into mulch by cultivating strips between grass and mulch. Attention to sod lanes near the ground is emphasized to weaken quackgrass and Canadian thistle, highlighting the importance of prioritizing weed management during this critical period. If not managed early in the season it can be challenging to reclaim later in the season.

That’s all for now! Check out the notes from my next chat with Chris in two weeks on May 17.

This article series is NOT intended to be prescriptive for other orchards. It is simply an opportunity for our readership to hear from other growers about their experiences growing fruit crops in Wisconsin.

Growing the same crop does not always justify the same practices. Management decisions at your farm should be tailored to your operation and take into consideration location, regional climate, disease and pest history of your vineyard, and your varieties.

The mention of a product is NOT an endorsement. Always follow the instructions on product labels and consult weather stations (ex. NEWA) in your area for current weather forecast and disease and pest prediction models.

This article was posted in Notes from the Field and tagged Chris McGuire, Leslie Holland, Notes from the Field, organic, organic apples.