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Finding the Cause of Bark Scaling in Florida Citrus Groves

At UF/IFAS, we are working on finding solutions for Florida’s citrus growers. This is a summary of one project made possible by state legislative funding for the UF/IFAS Citrus Initiative during the 2018-19 cycle. It documents how we are making progress and providing Florida growers with reasonable, pragmatic solutions to successfully grow citrus in the new age of citrus greening.

Researcher: Amit Levy, Plant Pathology

IMPACT: Growers are placing a lot of hope and money into planting newly developed citrus varieties that are more tolerant of HLB. However, some growers are experiencing new disease issues like bark scaling which can reduce the productivity of these new varieties.

This research has been important in ruling out  certain suspected pathogens and is narrowing in on finding the true pathogens involved in this new problem. This work is important for ensuring success of groves being planted now that will sustain the citrus industry over the next 20 years.

When a commercial citrus research grove in Polk County, experienced issues with bark scaling during field trials of newly developed citrus varieties, UF/IFAS  plant pathologist Amit Levy investigated. Together with colleagues, he developed a process to screen for diseases found in Florida citrus that are caused by viroids or viruses. Levy tested numerous samples from trees in the affected grove, including asymptomatic trees  and specimens expressing strong symptoms. He determined that none of the six pathogens under investigation were responsible for the mysterious outbreaks of bark scaling, suggesting a previously unknown causal agent might be present. A second round of sampling and analysis ended with the same result. This set the baseline, ruling out viroids and
other viruses as the cause of this problem. Having established the process for testing for some viruses, other grower problems can now be tested quickly.

One Comment on “Finding the Cause of Bark Scaling in Florida Citrus Groves

  1. Look at Diplodia as a causal agent. Known to cause Lime Bark Disease, Gummosis and twig dieback.