Inconclusive HLB Tests Remind Growers of Disease Threat

Taylor HillmanFruits & Vegetables, Pest Update

Inconclusive HLB
Central Valley citrus growers got a reminder how close the deadly disease huanglongbing is to the industry with a discussion about inconclusive HLB tests found in their area. The Citrus Research Board and University of California Cooperative Extension combined to bring California citrus growing areas an educational seminar, and it started in Exeter for Central Valley growers.

Research Entomologist, and Director of the Lindcove Research and Extension Center, Beth Grafton-Cardwell gave an update on the Asian citrus psyllid and huanglongbing situation in California. As AgNet West has talked to Grafton-Cardwell about before, inconclusive results from trees tested for HLB-causing bacteria continue to concern researchers.

There have been several polymerase chain reaction (PCR) tests, the current test to determine if a tree is infected with the bacteria that causes HLB, which have been deemed inconclusive by testing standards. Those results concern many researchers and lead to the assumption that there are likely more infected trees in the state than the industry has identified.

Grafton-Cardwell said several of those inconclusive samples were found in residential areas of the Central Valley, an area of the state where psyllid control is a priority because the disease has yet to be found north of the Grapevine. A total of nine residential trees in the Central Valley had PCR tests come back as inconclusive. Grafton-Cardwell emphasized the need for growers to stay aggressive with area-wide treatments and other psyllid management practices.