An extract found in oak trees may hold the key to protection for citrus trees for farmers concerned about deadly citrus greening, say researchers at University of Florida Institute of Food and Agricultural Science (UF/IFAS).

Scientists' most recent work focuses on "quercus leaf extracts" and their curative effects that restore leaves infected by HLB. Quercus is the Latin name for oak.

In these findings, they outline how citrus leaves treated with oak extracts showed "a decrease in the presence of the bacteria".

Lorenzo Rossi, assistant professor of plant root biology at UF/IFAS was quoted in a university release saying that research scientists "work with a sense of urgency to contain the pathogen and to manage HLB’s impact on our important crop”.

Rossi works alongside other researchers to develop strategies to manage fruit on trees impacted by citrus greening. For years, growers across the state noted that citrus trees that were located under oak tree canopies or next to oak trees were healthy. While at the same time, citrus trees like grapefruit that were a few rows away from the oak trees showed signs of HLB.

This intrigued investigators to begin looking into the potential of oak trees for citrus greening. The region in Florida where the research is being carried out is known for its grapefruits, detailed the release.

Other research results showed that HLB-affected citrus plants treated with oak leaf extract were better able to absorb nutrients. Researchers saw increased chlorophyll content and plant nutrition as well.

The team is currently developing water and nutrition management practices to extend the lives of HLB-infected trees - a project funded by the Citrus Research Development Foundation and the USDA. Scientists' most recent work focuses on "quercus leaf extracts" and their curative effects against a certain compound that restores leaves infected by HLB.

“This study suggests that oak leaf extract will provide a new management treatment program to protect trees that have HLB,” said Rossi. “We will continue to develop a protocol for growers to produce our high-value citrus crops and to reduce the symptoms of HLB on the trees."

To read the full release, click here.