When to spray Surround for plum curculio on plum trees in Spring

Asked January 6, 2020, 5:52 PM EST

My Mt. Royal plum tree, and to a lessor extent my wild plum trees (Prunus Americana) and Black Ice have been devastated by plum curculio the last few years. All six trees are in a row next to a wetland. The Mt. Royal lost nearly 100% of its fruit the last few years. I sprayed with Surround for the first time last year, but AFTER blossoms had opened. I noticed that the Surround was thin/watery in some places and thicker in others. When should I spray on the Surround? I pick up most of the fallen fruit and dispose of it away from the tree area and keep the grassy orchard clean. I keep all the trees pruned. Any suggestions are welcome. when should I spray the trees with Surround and are there other options worth looking at. I'm thinking of making a large sleeve out of floating row cover to cover at least a few branches in hopes of saving some of the fruit. The Mt. Royal is suppose to be self-pollinating, but I am concerned that if the flowers are covered they will not get pollinated. Thank you for any help/suggestions.

Stearns County Minnesota

1 Response

Thank you for writing. You have a difficult problem.
This site contains good information on the SURROUND product, spacing of doses. https://extension.umaine.edu/fruit/growing-fruit-trees-in-maine/insect-pests/
Other pesticides risk damage to pollinators.
This site is even more detailed and it suggests heavy coverage of the barriers.
There are many descriptions of bagging fruit. This tells a variety of techniques.
Here is another description. https://extension.umn.edu/yard-and-garden-insects/apple-maggot#bag-apples-1814711 I hope this helps.