Trunk Injection Not a Silver Bullet for HLB

Josh McGillDiseases, HLB Management

Although trunk injection of oxytetracycline hydrochloride  (OTC-HCl) has received much recent press for its promise in managing HLB, there is still no silver bullet for the devastating disease. That was part of plant pathologist Ozgur Batuman’s message at a Dec. 10 seminar addressing HLB and other citrus diseases that may exacerbate HLB’s effects on trees.

Oxytetracycline hydrochloride is applied in tree trunks with an injection device via a drill hole for HLB treatment.

“There is no single effective control strategy for HLB,” said Batuman, University of Florida Institute of Food and Agricultural Sciences assistant professor of plant pathology at the Southwest Florida Research and Education Center in Immokalee. But Batuman said growers can maintain production in the face of HLB through several integrated pest management tactics (IPM). They include:

  • Monitoring for all pests and diseases and acting on them
  • Reducing inoculum sources, possibly by use of OTC-HCl injection
  • Removing unproductive trees and establishing clean resets
  • Reducing populations of the Asian citrus psyllid that spreads HLB
  • Improving plant nutrition and irrigation programs

He said the best control would be relying on those tactics and having HLB-resistant or -tolerant citrus cultivars in the near future.

HLB reduces the efficacy of phytophthora management, Batuman said. He added that improving fungicide timing, number of applications and rates are needed to achieve better control.

Although citrus leprosis has not been found in Florida since the 1970s, it is considered one of the world’s most important emerging citrus diseases, Batuman said. Symptoms of leprosis include premature leaf and fruit drop.

Batuman said Florida’s climate is highly suited for the establishment of leprosis. He emphasized that preventing its re-entry into the state is much easier than trying to eradicate or control it. It is essential to avoid bringing propagation materials into Florida from areas infected with leprosis, he said. 

CYVCV was first discovered on lemon and sour orange trees in Pakistan in 1988. The disease was detected on dooryard citrus in California in 2022.

As with leprosis, Batuman warned that Florida’s climate is suitable for CYVCV and that it is best to keep it out of the state. He also urged avoiding bringing propagation materials to Florida from infected areas.

About the Author

Ernie Neff

Senior Correspondent at Large

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