Verticillium Wilt and systematic fungicides
I've removed a 15-20 year old Surgar? Maple due to what certainly looks like Verticillium Wilt and plan on removing another. I also have a Japanese Lilac that my Agronomist neighbor is sure that had a fungus earlier due to the llok of the leaves that started falling off early summer. I also have a number of perrenials that must have had something also with the leaves eventually turning black. Not a small yard, but still within wind of each other. I'm wondering if a systemic fungicide annually applied to the area would help? The instructions of constantly removing affected leaves/plants probably won't happen on a timely basis. I plan on spraying a topical fungicide on the Lilac when I spray my Crabapple trees hoping that is what it needs. Any thoughts?
It's difficult to know to what extent applying a fungicide will benefit the plants. That would depend upon whether the organisms causing the problem are in fact fungi and whether the product applied is labeled for use to control fungal pathogens on the particular plants showing symptoms. Several pathogens may be affecting the plants, so targeting controls is preferred to a shotgun approach.
If you send us sharp photos of affected leaves, stems,etc. next spring/summer we may be able to identify what's causing the damage and prescribe controls. In some cases that may not be possible from viewing photos. If so, laboratory analysis by the University of Minnesota Plant Disease Clinic would be necessary.
In any case, a general annual fungicide treatment isn't advisable. Products must be used according to label directions and the frequency and amounts of product recommended vary depending upon the kinds of plants and diseases targeted.
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