Skip to main content
ARS Home » Southeast Area » Fort Pierce, Florida » U.S. Horticultural Research Laboratory » Citrus and Other Subtropical Products Research » Research » Research Project #435684

Research Project: Prophylactic Treatments to Prevent Huanglongbing

Location: Citrus and Other Subtropical Products Research

Project Number: 6034-21000-019-002-R
Project Type: Reimbursable Cooperative Agreement

Start Date: Oct 1, 2018
End Date: Sep 30, 2020

The objective of this project is to determine the efficacy of prophylactic (or curative) treatments to mitigate the development of Huanglongbing disease in citrus. Heretofore treatments have been evaluated following the development of Huanglongbing in Candidatus Liberibacter asiaticus infected citrus trees. Unfortunately, none of the treatments have provided benefits, likely because the disease severity was too great to overcome. Our hypothesis is that preventive treatments will arrest Candiatus Liberibacter asisaticus prior to the development of disease symptoms.

We will use a novel model system that has been developed at the USHRL for screening compounds for their effects on Huanglongbing disease development. Citrus medica (citron) trees will be produced from nodal cuttings. Treatments (various antibiotics, plant growth regulators and nutritionals) will be applied to the experimental plant material prior to exposure to Candidatus Liberibacter infected Asian citrus psyllids, the insect vector of the pathogen. Following exposure to the insects, plants will be monitored for Candidatus Liberibacter infection and development of Huanglongbing symptoms. Compounds showing positive effects in the citron model will be further evaluated in Valencia orange in greenhouse studies. If compounds show benefits in the greenhouse with Valencia orange, field trials will be established to determine efficacy in commercial production systems.