Texas counties dealing with oak wilt

By MANDY SPIKES | Central Texas Edition

Rene Burks, with the Texas Forest Service, talks about the problems associated with oak wilt and how to control it. -- Photo by Mandy Spikes

April 3, 2003 -- Problems associated with oak wilt and grasshoppers, as well as ways to control them, were two of the topics covered at the Farm/Ranch and Dairy Day held Mar. 27 in Comanche.

Rene Burks, with the Texas Forest Service, discussed the problems that oak wilt can cause and ways to control it, while Dr. Jeff Tomberlin, Extension entomologist with Texas A&M University, talked about the invasion of grasshoppers and how to control the situation.

"My reason for being here today is to talk to you about oak wilt, which is different from oak decline," began Burks. "Oak decline is a condition. Oak wilt is a vascular fungus that prevents water from getting to the roots and leaves."

Burks stated that over 60 counties in the state have to deal with oak wilt, but it is concentrated in Central Texas.

The disease mainly attacks the species in the red oak family. Once it gets into the red oak, the tree quickly turns bright red and the leaves are green, mixed with brown or yellow. "Once you have a tree with oak wilt, the best thing to do is get it out real quick so that it doesn't spread to other trees."

She said one in ten red oaks will form fungal mats, which is caused by the disease. This tends to attract small bugs that feed off the fungal mats and cause problems in the area.

"Oak wilt is spreading all over because of deer hunters. They take red oaks with this disease home for firewood and store it, which causes it to spread to other trees nearby.

"It's not impossible to control oak wilt. You should be careful when you are pruning your trees, especially from February to June. If you are going to prune, wait until July or August."

Burks explained that another way to manage oak wilt is with a fungicide treatment. "It's better to treat a healthy tree than a tree that already has it. This will not prevent a tree from getting oak wilt, but it will help it survive a little better if it does get it."

"When you think about grasshoppers, you need to know the types of grasshoppers around and how to control them," explained Tomberlin. "In Texas, there is a definite problem."

He said when there is a grasshopper outbreak, it usually involves more than one species. "These insects destroy vegetation indiscriminately. This should be considered an invasion rather than an infestation.

"There are 150 species of grasshoppers in Texas. They lay their eggs in grass ditches and rangelands. They eat half their weight everyday. Their eggs hatch in mid-April. The information given to you today should help your control of them for the future."

Tomberlin stated that grasshoppers prefer the rangeland, not a yard or vegetable garden. "They move on to your yard or garden when they can't find anywhere else to eat. They like bare ground and vegetation with an open canopy. They also like the sunlight, where there is low humidity."

He gave three types of control when dealing with these insects: cultural, biological, and chemical. "Control should begin before grasshoppers move into the landscape," he added.