Microinjection using Chemjet Tree Injectors and the fungicide propiconazole were used to successfully arrest an outbreak of oak wilt in a densely wooded area in Northern Michigan without the need for trenching around the infected trees. Oak Wilt was identified with several adjacent dead and dying red oaks in a localized area.
Chemjet Tree Injectors were used to inject a propiconazole solution at a rate of 10 ml of 14.3% propiconazole per inch diameter at breast height (DBH). A solution of 50% propiconazole 14.3 plus 50% tap water was mixed and 20 ml of this solution (containing 1.56 grams propiconazole) was injected using Chemjet Tree Injectors at three inch intervals around the circumference of trees about two feet above ground.
Twenty healthy red oaks ranging in diameter from 8 to 24 inches were injected in all directions radiating outward to a distance of about 100 feet beyond oak wilt infected trees during August 2016.
Six infected and dying red oaks within in the outbreak area were then cut down in September 2016.
As of September 2017, thirteen months after treatment, no new infections of oak wilt have been identified in any of the treated trees. The photo below shows the stump of an oak wilt infected and removed red oak, with healthy red oaks immediately adjacent to the killed tree. Treated trees have red dots.
Below: View of healthy treated tree tops immediately adjacent to oak wilt killed tree stump shown in photo above
While it is premature to conclude that the oak wilt outbreak has been eliminated, it is encouraging to see that the fungus has not transferred to any adjacent red oaks (some only five feet away) after a period of one year. Propiconazole microinjections will be conducted for trees in this treatment area in 2018 and 2020. If no new oak wilt infections are identified by 2022, then injections will cease.
For information on how to treat other tree diseases and pests check out the links below:
Logical Result LLC is a North American Distributor for Chemjet Tree Injectors. We have also posted a few links to some other products that will refer you to Do My Own pest control. If you click the links provided for Do My Own to purchase items, we may receive a referral commission as an affiliate of the sellers at no cost to you.