Southwest Michigan Fruit update – June 10, 2025
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EmailIt’s starting to feel more like summer!
MSU Fruit Updates
Michigan State University Extension is in the process of filling the tree fruit specialist position based at the Southwest Michigan Research and Extension Center. Because of this, there will be a more abbreviated tree fruit section in our weekly updates until the position is filled.
We are also moving our weekly IPM updates to a virtual format and dividing them to tree fruit and small fruit specific meetings. The small fruit weekly updates are on Tuesday evenings. Tree fruit weekly updates began on Wednesday, April 16th. We are hoping to return to joint small and tree fruit updates next year. Thank you for your understanding and happy spring!
Weather
Southwest Michigan saw very seasonable weather last week. Temperatures largely rose to the mid to upper 70s most days. Lows remained in the 50s. Average humidity for the week was also higher than the last few weeks before.
A storm system moved through southwest Michigan last Wednesday, leaving about an inch of rain behind in most locations. Another round of more scattered, but sometimes intense storms came through on Sunday and Monday, dropping another tenth of an inch of rain. Weekly total rain amounts were one to one and a half inches of rain for the region.
The next week is predicted to be seasonable as well. High temperatures should remain in the upper 70s most days. A weather system is expected to stall over Michigan in the latter half of the week. The rain associated with this system is not predicted to be heavy or consistent. But the potential for repeated scattered rain on Thursday through Saturday, and potentially longer, has rain amounts possibly up to three quarters of an inch or more for the southwest region.
Tree fruit
Plum curculio oviposition continues. Neonicotinoids are recommended as oviposition deterrents as well as a general toxicant at this time.
Peach and nectarine many varieties are over an inch in size. Pits are still soft.
Apple scab primary spore season is coming to an end. Many varities are over an inch in size. Chemical thinning season is over for most growers.
Small fruit
Grapes Concord juice grapes are blooming, as are some early hybrids. Clusters are elongating on most varieties, indicating bloom should be in the next week or two if the seasonable weather holds.
As we get close to bloom, this is when we shift our disease focus to black rot and other diseases that can impact fruit clusters. With the exception of powdery mildew, diseases that infect grapes in Michigan typically require rain events to disperse the spores. It only takes 0.1 inches of rain above 50 F to trigger a possible infection.
Wild grape bloom is underway. Some early sites were observing bloom as early as May 27th, but the cold shortly after that slowed progress. Most locations started reporting more bloom by June 1 and 2. The regional date for wild grape bloom is likely June 2, 2025. Wild grape bloom is used as a biofix for grape berry moth. Biofix is when 50% of clusters are at 50% bloom. See this Michigan State University (MSU) Extension article for more information: Using the MSU Enviroweather grape berry moth model in 2018.
Blueberry green fruit are here! Spotted wing drosophila (SWD) catches increased over the last week. Cranberry fruit worm continues to be caught and there has been an uptick in catches this week. Sprays for CBFW with residual action should be taking place soon if they haven’t already. Anthracnose risk continues to be low. If you are a grower in Michigan and haven’t taken advantage of Michigan Blueberry Commission’s partnership with the MSU plant and pest diagnostic clinic, keep it in mind as we progress through the season. This partnership allows for every blueberry grower in Michigan to get submit up to two samples to the PPD clinic for free! Follow this link for the form.
Strawberry harvest is under way. Several U-pick operations opened over the weekend, with healthy customer numbers with others planning to open later this week. Frost damage has been observed.
Brambles fruit is developing in summer bearing raspberries. Fall bearing varieties continue to grow.
Upcoming meetings
Join us at our pre-harvest blueberry meeting on June 16. Follow this link for sign up and more information.
This year, in lieu of our historical Monday Night Fruit IPM Meetings, we will instead be hosting Tuesday night small fruit IPM meetings. They will take place entirely online and will start at 5:30 on April 1 and will occur weekly until June 24. Sign up here.
Tree Fruit IPM Lunch meetings began on April 16, follow this link to sign up.
