State declares citrus quarantine in Fallbrook

Asian citrus psyllid

The California Department of Food and Agriculture declared a new citrus quarantine in Fallbrook on Sept. 16 after detecting the fatal citrus tree disease known as Huanglongbing (HLB), or citrus greening, in one mandarin tree in a residential neighborhood in the Fallbrook area during regular inspections.

This bacterial disease is a major threat to San Diego County's $138 million annual citrus crop and can impact residential citrus tree owners. HLB causes misshapen, bitter fruit and eventually kills infected trees. There are over 456 businesses that may be affected by the new quarantine, including over 100 growers with approximately 830 acres of commercial citrus, four commercial nurseries, and a farmer's market in downtown Fallbrook.

This new quarantine adds to the existing HLB quarantines in Oceanside, Rancho Bernardo and Valley Center. It covers the area bordered on the north by De Luz; to the south by SR-76 and Camino Del Rey; to the west by Camp Pendleton; and to the east by I-15. The maps for this HLB quarantine are available at https://www.cdfa.ca.gov/citrus/pests_diseases/hlb/regulation.html.

The intent of the quarantine is to protect the region's food supply, agricultural economy, and environmental sustainability by restricting people and businesses from moving citrus nursery stock, plant parts, and fruit outside the quarantine boundaries and off their properties. The only exception is for agricultural businesses that must adhere to specific requirements for treatment, cleaning, and packing commercial fruit prior to movement.

The disease is not harmful to people or animals but is deadly to citrus and could be devastating to the county's citrus industry. HLB is spread by tiny insects, the Asian citrus psyllid, if they are carrying the bacterium when they feed on citrus trees. Samples from trees on the property where HLB was confirmed – as well as the surrounding area – are undergoing tests for the disease.

"Unfortunately, Huanglongbing is fatal to citrus," said San Diego Agricultural Commissioner Ha Dang, "so our goal is to prevent this disease from spreading. By working together, we can all protect our food supply, local agriculture, and environment from this devastating disease. Partnering with state and federal regulatory partners, we are working closely with residents and agricultural operators and ask for everyone's cooperation with the ongoing regulatory activities."

The California Department of Food and Agriculture will work with residents in the immediate area to arrange for treatment of citrus trees as a protective measure against the disease. County officials are also proactively notifying local citrus growers, plant nurseries, and other related businesses.

If the disease is detected in additional citrus trees in the quarantine area, CDFA officials will contact properties regarding treatment and removal of the infected trees. Nearby trees will be treated, and regulatory survey efforts will be increased to prevent the spread of the disease in the area.

Infected trees may have areas with mottled yellow leaves, generally seen in asymmetrical patterns and bear small, asymmetrical fruit, which is partially green, bitter, and not fit for sale or eating. The disease destroys the appearance and economic value of the trees and eventually causes their death, typically within a few years.

Inside the quarantine area, the County urges residents to take the following steps:

• Do not move citrus plants, leaves, or foliage into or out of the quarantine area.

• Remove all leaves and stems, and thoroughly wash backyard citrus before moving from the property where it was grown.

• Dry or double-bag plant clippings prior to disposal.

• Cooperate with agricultural officials who are inspecting trees, taking samples, and treating for the pest.

• If residents no longer wish to care for a citrus tree, consider contacting a tree removal service to discuss options to help ensure trees do not continue to be a host to the pest and disease.

• Only buy citrus trees from reputable local nurseries.

• Report citrus trees that seem to be sick or dying even though they also appear to be well-watered and well-maintained by contacting CDFA's toll-free Pest Hotline at (800) 491-1899 or visit https://www.cdfa.ca.gov/citrus/.

• Visit https://californiacitrusthreat.org/ to learn more about the pest and disease and to see pictures.

• For questions regarding moving commercial citrus and HLB quarantine regulations, please contact the San Diego Department of Agriculture, Weights and Measures at 760-752-4700 or visit https://www.sandiegocounty.gov/awm/.