The browning, wilting leaves on the tree branches in the McCarty Hall courtyard foreshadow the end for the biggest avocado tree on campus.

But it also presents the beginning of a much bigger concern for UF forestry experts.

The tree is suffering from Laurel Wilt Disease, which has swept across the southeast United States in the past decade, terrorizing avocado and other trees susceptible to the disease.

“Avocados are at real risk of being wiped out,” said Jason Smith, an assistant professor of forest pathology. “It’s a real big concern.”

The disease, which is caused by beetles cultivating fungus inside the tree, can kill a tree in as little as a week.

Smith said that, though the disease is lethal to the trees, it is not a human health concern.

In other words, fruit from a tree with Laurel Wilt would be fine to eat.

Nothing can be done to save the dying avocado tree by McCarty Hall, but Smith and several UF graduate students are working to find ways to prevent other trees from being infected.

Friday morning, UF graduate student Don Spence injected a campus Redbay tree with fungicides to protect it.

He hooked up tubes to the tree, which put the fungicide inside.

“It’s essentially an IV system for the tree,” Smith said.

However, the tree treatment doesn’t come cheap. The cost is around $100, Smith said, but hopefully it will protect the tree for about three years.

The focus is currently on preventive measures in the short-term, Smith said. For the long-term, Smith and Spence are researching what makes certain trees survive Laurel Wilt.

The beetle that spreads the disease reproduces quickly and cannot be eradicated, Smith said.

The disease also spreads as infected trees are cut down and moved from place to place for things such as firewood.

However, Smith says, it will take time for UF to find the proper defense.

For now, that is all that can be done.

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Laurel wilt is a deadly disease of red bay and other tree species in the Laurel family, including the avocado tree. The disease is caused by a fungus that is introduced into host trees by a non-native insect, the redbay ambrosia beetle. The disease was likely introduced into the US on infested wood packing material. Use local firewood only and become familiar with the disease and symptoms. or

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