Originally Posted By: LoneRanger
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I also put a 2nd treatment of antifungal on a Golden Niobi Willow tree that got Willow blight fungus last Autumn bad enough to cause some die back. 1st treatment was in Autumn, 2nd this past weekend, both on recommendation of local certified Arborist. Told me to use Monterey Fungi-Fighter w/ Propiconazole, mix at proper rate and pour into shallow trench in perimeter around trunk to enable root take-up of the product. I'm glad to report the tree is covered in new leaf shoots as we speak so we didn't lose it, which was a concern due to the die back. There is some apparent bark loss around the trunk right at the dirt level that concerns me though. It is an awesome tree and is on the southwest corner on our side of a shared 100' x 68' pond and looks very good there, do not want to lose it. Got a little concrete sittin' bench by it and all.
Lone Ranger,
A number of details regarding your Willow blight program raises red flags for me. Willow blight is a generic term applied to foliage and twig dieback when 2 different diseases coexist: Scab (Venturia spp) and black canker (Glomerella miyabeana). The infection period for these seems to mostly be in spring and early summer. An autumn application of fungicide would seem to have little effect (at least in my region).
Propiconazole is mostly recommended as a foliar spray every few weeks during the infection period. Flare bark injections can be utilized for a few specific problems. I do not see scab/black canker on the label for willows and this treatment requires special injection equipment. Pouring the product around the root collar seems ineffective, since the material needs to get into the transport tissue underneath the bark. Soil contact tends to bind it up and hastens break down.
Commercial product label:
http://www.cdms.net/LDat/ldUJQ002.pdf 14% active ingredient vs. 1.5% for yours.
I will be interested to have you come back this fall and share your results. Also, ask your tree care person if he has personal experience with this technique. Maybe its something thats used in the trade circles that circumvents the label instructions. I haven't heard of this system in my area.
Make sure you do general tree care that involves removing all of the old infected leaves/twigs from last year and maintain good vigor(adequate soil and water health). This will help the tree resist infections naturally.
Take care.