Why oak mulch could save your citrus from greening disease

Hurricane destruction leads to constructive citrus growth

Oak mulch helped decrease citrus greening. (.)

How is it possible the impetus for saving orange trees from citrus greening could have been from Hurricane Dorian’s destruction?

It was part of a chain of events that sparked research into using oak mulch to combat citrus disease, and the results are helping trees survive.

Researchers rented a wood chipper to make oak mulch in Ft. Pierce after hurricane damage. (Indian River Research and Education Center)

Scientists have been looking for ways to help Florida citrus growers fight the most severe citrus disease in history and the solution may be to spread oak mulch around the drip line of citrus trees.

Growers have claimed a beneficial connection between oak and citrus trees. Citrus growing under a canopy of oaks have minimal disease symptoms compared to more severe cases for trees less exposed to oaks.

University of Florida post-grad researcher Lukas Hallman suspected oak trees could have beneficial antimicrobial compounds, but he only began testing them after an oak tree fell down in the hurricane.

Hallman used mulch from the tree under citrus trees planted at the USDA Agricultural Research Service in Fort Pierce. Months of data showed oak amendments improved the soil and that the compounds in the mulch help citrus trees weather the disease.

Plants treated with oak leaf in the lab had bigger roots, greener leaves and overall bigger plants. Negative values indicate decreasing harmful bacterium (.)

Research over the next two years between the UF/IFAS Indian River Research and Education Center and the U.S. Department of Agriculture Agricultural Research Service in Fort Pierce, will try and identify which compounds are beneficial, where those compounds are found in the trees and which oak species hold the specific compounds. Those answers can help determine how much is needed to control the disease.

In the meantime, if you have any fallen oak trees, you may want to find a wood shredder and chip away for more fruitful days ahead.

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