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Showing results for tags 'knotweed'.
Here's a quick overview of the treatments ISN has found most successful for controlling knotweeds: Milestone (aminopyralid) Faster kill (~3 years), more off-target effects Standard rate (3-7 oz/acre; 0.01%) Using nonionic surfactant (standard rate) Late spring (3-4 ft high) or late summer (at least 60 days before frost) When treating in late summer, it is helpful to do a cut of the plants a month or so in advance ONLY IF safe disposal of the stems is possible At some sites, repeat treatments (spring & summer) may be appropriate, so long as maximum application rates are not reached Not aquatic approved Note: Tree sensitivity issues--some trees will die if their roots mingle with knotweed that is treated with Milestone. Clearcast (imazamox) Acceptable kill (~5 years), fewer off-target effects Cocktail: 5% Clearcast 1-2% Methylated Seed Oil (MSO) Not all MSOs are aquatic-approved!! Check before applying to knotweed in areas with standing water 1-2% glyphosate (aquatic-approved formulation) Best sprayed in late summer/early fall Spraying at least 60 days before the first frost is CRUCIAL--this date will vary by location (for northwest lower MI, it's early August) Aquatic approved (if adjuvants are aquatic-approved) We have applied both of these treatments as either foliar spray or as a "cut stem" application (cutting down stems and filling the stem cavity with herbicide solution), which is a great way to avoid drift and overspray, but is more time-intensive and contains the risk of stem disposal. Questions? Comments? Leave a note!
Hi all, Has anyone done DNA tests on knotweed to determine whether it is Japanese, Bohemian or Giant? I'm working with an Oakland University professor on this and just curious if anyone has tried it before in Michigan. Let me know if so! Also curious once we determine which varieties are present in our area whether the treatment effectiveness may vary depending on the variety. Any insights appreciated, thanks!