FORT SMITH (AP) — Drought that began in 2011 is damaging and killing oak trees in western Arkansas, and the effects will likely linger despite vastly improved soil conditions, an official with the Sebastian County Cooperative Extension Service said.
Extension Staff Chairman Lance Kirkpatrick told the Times Record that two years of drought has weakened the immune systems of the trees and that many trees that appear in distress are already dead.
"I get calls from people saying, ‘My tree is sick,’ and when you go out and look at it, the bark is already sloughing off and it actually died last year," Kirkpatrick said.
Kirkpatrick said a fungus, hypoxylon canker, which attacks all oak species in Arkansas from the inside out, destroys the tree’s water-conducting tissues.
Stress from drought compromises a tree and allows pathogens — such as the fungus — to potentially destroy the tree, said Alison Lichy, urban forester for the University of Arkansas at Fort Smith.
"A healthy tree will be able to pretty much fight most things off itself. But with the stress (from drought), the tree is using all its resources and nutrients and that’s how these things get into them," Lichy said.
Kirkpatrick said an early symptom of the fungal infection is yellowing and wilting of upper leaves, which people miss or mistake it for the tree just "shucking" its leaves. Ultimately, the fungus causes the bark to separate from the tree.
Both Lichy and Kirkpatrick said they normally don’t recommend fertilizing trees, but during periods of drought, fertilizing along with watering can help reduce stress and make trees less susceptible to disease.
The latest U.S. Seasonal Drought Outlook released May 16 by the National Weather Service Climate Prediction Center projects no drought in Arkansas through the end of August.
The current U.S. Drought Monitor, released Thursday, shows moderate drought in southwestern Arkansas to abnormally dry conditions in northwestern parts of the state.
Information from: Southwest Times Record, http://www.swtimes.com/