Dogs specially trained by Agriculture Research Service (ARS) scientists have proven to be the most efficient way to detect huanglongbing -also known as citrus greening. This is according to a paper just published in the Proceedings of the National Academy of Sciences.
Currently, the best hope of curtailing the spread of citrus greening is to eliminate trees with the disease as quickly as possible to prevent further spread. Early detection of the citrus greening pathogen is crucial because trees can be infected and act as a source to spread the disease months or years before showing symptoms that are detectable by the naked eye.
ARS plant epidemiologist Timothy R. Gottwald with the U.S. Horticultural Research Laboratory in Fort Pierce, Florida, discovered that dogs can be trained to sniff out the presence of Candidatus Liberibacter asiaticus, the bacteria that causes citrus greening, with greater than 99 percent accuracy.
"We found that, once trained, these dogs were able to identify infected trees within two weeks of the trees being inoculated," Gottwald said. "The dogs also were able to distinguish the citrus greening pathogen from a variety of other citrus bacterial, viral, fungal, and spiroplasma pathogens, including closely related Liberibacter species.
During testing, the citrus greening detector dogs had total of 4 to 15 false negatives and false positives on 950 to 1,000 trees per dog. Occasionally, the dogs alerted on clean trees that were in the same spot where an inoculated tree had been placed in previous tests due to residual scent.