When emerald ash borer swept through the Midwest it left three kinds of ash trees in its wake: the dead, the dying, and the diligently protected and thriving. The hunt was on for ways to stop this insect and save North America’s ash trees. Now, nearly 20 years later, not only do we have tools to fight this insect but we are developing better management techniques every day. Treating ash trees with emamectin benzoate has long been shown to be effective against emerald ash borer but new data shows that a single injection can last 3 growing seasons. Emamectin benzoate is injected into the trunk of a tree and travels throughout the live parts of leaves and stems. Insects that feed on this tissue are killed when they ingest the emamectin benzoate. Although this insecticide can kill adults in leaves for only 2 years, it lasts at least three years[Read More…]
Archives for January 2019
Avoid injury from falling ash limbs by promptly removing dead and dying ash trees. Don’t do it yourself! Hire a professional to safely remove your brittle trees.
This looks to be shaping up as a tough winter for us and our trees could be damaged, be prepared with these winter tree tips
Sitting in your back yard on a warm day under the shade of a tree is one of the joys of spring, but there are a growing number of threats that could destroy this experience. Invasive species present dangers like those from above in the form of fragile dead ash trees and from below in the form of new tick species. Learning to prevent, protect, or recover from these pests can mitigate their devastation. Emerald Ash Borer University is an online webinar series produced by a partnership between three universities and the US Forest Service that allows listeners to learn about invasive species and ask questions of experts without leaving their home or office. All webinars are free and many can be used towards continuing education programs (contact Elizabeth Barnes for details). Can’t watch it live? No problem! All webinars are recorded and posted online after the talks. To register[Read More…]
A look back at the past year may help us be alert to problems ahead. Here’s a summary of the most common problems received in the diagnostic lab on woody ornamentals in 2018. As is typical for most years there were more non-disease (abiotic) problems than infectious (biotic) diseases found on PPDL lab samples in 2018 (see Table 1). These abiotic problems include aggregate counts of everything from poor planting practices to soil conditions and environmental factors. The table also shows the most frequently diagnosed infectious disease problem was Botryosphaeria dieback or canker, which was found across a range of hardwood trees and shrubs including: Maple, Magnolia, Crabapple, Redbud and Oak. The most commonly submitted leaf disease was Tubakia leaf spot on oaks, which is usually more severe on the red oak group. We also had our first recorded samples of Bur oak blight (Tubakia iowensis) on Bur oak and[Read More…]