Oak wilt is described as being controlled by what method?

• A. Fumigation with soil-applied pesticides
• B. Mechanically severing root grafts
• C. Selective pruning of infected trees
• D. Installing root barriers

Answer: (B)

Oak wilt moves mainly through underground root grafts that connect trees, allowing the fungus to hop from an infected tree to healthy neighbors. The most effective way to control it is to mechanically sever those root grafts between diseased and healthy trees, which breaks the underground transmission pathway and slows or stops new infections in the stand. Other options aren’t as effective: fumigation with soil-applied pesticides isn’t a practical treatment for live trees with oak wilt; pruning infected trees doesn’t stop the subterranean spread and can even spread spores if done at the wrong time; and installing root barriers can help reduce future spread to newly planted trees but doesn’t address the existing underground connections in an infested area.