Tree Fruit Newsletter — June 10, 2026
Thinning Outlook
At the Highmoor Farm, fruitlet diameter has reached 12 to 14 mm for the king fruits and 8 to 12 mm for the side fruits, so there is still time to apply thinners again if the first application was not enough. We applied thinners 6 days ago, but it was not yet evident how well it worked when I checked yesterday. It takes 7 to 10 days to see an effect, so by the end of the week, we should see signs of thinning. If they are easily pulled of the cluster, they have been thinned and will naturally drop a few days later. Use a tugging motion rather than twisting since twisting them off will lead to an overestimation of thinning.
If you need to apply a second application, most materials should still be effective this week, but by next week, Accede will be the better choice since it is effective for thinning larger fruitlets. Once they reach the 18 to 20 mm size, chemical thinners are no longer effective.
The forecast for later this week looks favorable for another application of thinners.
Renae Moran
University of Maine Cooperative Extension: Tree Fruits
PO Box 179
Monmouth, ME 04259
(207) 933-2100
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