Kansas Arborists Winter Conference 2013

          

 Kansas Arborists Annual Shade Tree Conference 2013

I was able to attend the KAA  conference last week.  It was a great conference and we were fortunate enough to have Dr. Ned Tisserat as a keynote speaker.

Dr. Tisserat was the former head of Plant Pathology at Kansas State University.
He is now with Colorado State University as Professor and Extension Specialist.

Dr. Tisserat and his research team recently discovered and named Thousand Canker Disease of Walnut.

I have known Dr. Tisserat since 1993. He is an incredibly smart man, generous with his knowledge and time.

He is able to take  detailed concepts and break them down for less brilliant minds to easily grasp.

I routinely sent him cuttings and samples to the Pathology lab at K-State. I always had endless questions

and concerns, he always had time for me and my questions. When I was a City Forester, he was instrumental in helping me control a serious outbreak of Oak Wilt.( I never forget people who helped me)

Dr. Tisserat covered many subjects at the conference.A short breakdown:

Drought-We are still in the midst of a major drought, some effects on trees are immediate, we may see growth and health issues relating to this drought over the next several years. Other secondary factors/ pathogens are opportunistic, will move in or colonize trees stressed by drought-esp. Canker Diseases, most are associated with drought conditions.

Cankers/Canker diseases-

Hypoxylon- The most serious, a diffuse type canker, these are one of the few cankers that expand and grow rapidly. These generally lead to tree mortality. I see this on Oak trees after construction activity.

Also included in this diffuse canker category is Thousand Cankers Disease of Walnut.

Cytospora- common on stressed trees, we see quite a bit of this on Cottonwood, Locust, Willow

and Spruce trees.

Nectria- very common on Honeylocust

Botrosphaeria- Crabapple, Pine, Spruce, Rocky Mountain Juniper

Fusarium- Common on Goldenraintree

*Each one of these Cankers has it's own distinct symptoms and fruiting structures used for identification-their own very distinct signature.

Thousand Canker Disease of Walnut-Unfortunately, this disease is headed our way.

There is a statewide quarantine on Walnut logs in Kansas, but that most likely will not stop

people from bringing in infected firewood from Colorado or elsewhere. As of this time,

there are no treatments proven to be effective. I spoke to Dr. Tisserat about this and some other disease issues. He feels it might be possible to treat Walnut  trees with Tree-Age or similar insecticide, but there is no research at this time.

One interesting point that he had is how many Walnuts there are in Kansas. They don't get a lot of attention, but they are in neighborhoods, parks, greenspace and woods everywhere.

Bacterial Leaf Scorch- This is a first for Kansas. Bacterial Leaf Scorch was found on an Elm and

diagnosed positively in a lab.Leaves yellow and appear scorched, tree is defoliated.

This is a fairly significant problem in Eastern states, but the first we have seen it in Kansas.

This bacterium is thought to be spread by insects, specifically  leafhoppers.

In most cases, slow decline of tree and eventual death of tree. Injections of antibiotics will supress symptoms, but are not curative.

Emerald Ash Borer-Is now here, will be a nightmare when beetle populations build.

This is what we can expect to see in untreated trees as populations build over time.
As the  USDA Forest Service map below clearly illustrates, Ash tree mortality rises rapidly as populations build.

I sound like a broken record, but if you have valuable Ash trees, you need to inject them with
Tree-Age insecticide for 2 years of control with a proven 99% success rate.

This is the short version of conference material. My personal thanks to Dr. Ned Tisserat for sharing vast amounts of information with us.

Ipsa scienta potestas est-

knowledge itself is power