Citrus Greening detected in California, USA; quarantine to affect more than 450 local businesses

By Sydney Brammer

The California Department of Food and Agriculture (CDFA) announced a new citrus quarantine in Fallbrook after discovering the citrus disease Huanglongbing (HLB).

Updated 2024 Huanglongbing quarantine boundaries in San Diego County. Photo credit: State Department of Food and Agriculture

The disease, also known as citrus greening, was found in a mandarin tree during routine inspections, adding to other quarantines already in place in North County.

Discovered on Monday, this bacterial disease poses a major threat to San Diego County’s $138 million citrus industry and can also affect homeowners with citrus trees.

HLB leads to misshapen, bitter fruit and ultimately kills infected trees. The quarantine impacts over 456 businesses, including more than 100 growers that work approximately 830 acres of commercial citrus. Other businesses include four nurseries and a farmer’s market in downtown Fallbrook.

This measure expands upon existing HLB quarantines in Oceanside, Rancho Bernardo and Valley Center. The quarantine area is bordered to the north by the unincorporated community of De Luz, south by state Route 76 and Camino Del Rey, west by Camp Pendleton and east by Interstate 15.

Maps of the quarantine zone are available online.

The quarantine aims to safeguard the region’s food supply, agricultural economy and environmental sustainability by prohibiting the movement of citrus nursery stock, plant parts and fruit beyond the designated boundaries.

The only exception applies to agricultural businesses that comply with specific treatment, cleaning and packing protocols before transporting commercial fruit.

While HLB is not harmful to humans or animals, it poses a severe threat to citrus plants and could devastate the county’s citrus industry. The disease spreads through the Asian citrus psyllid, which transmits the bacteria while feeding on citrus trees.

″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.″

Infected trees may show mottled yellow leaves in asymmetrical patterns and bear small, asymmetrical fruit that is partially green, bitter and unsuitable for consumption or sale. The disease damages the trees’ appearance and economic value, typically leading to their death within a few years.