Devastating Citrus Disease Threatens California’s Central Valley
A deadly citrus disease known as Huanglongbing (HLB) has recently been detected in Santa Paula, signaling a worrisome spread northward, posing a threat to California’s Central Valley. This alarming development suggests that it may not be long before the HLB bacteria infects the tiny, winged hosts already residing in Kern, exacerbating the citrus industry’s existing concerns.
Within a five-mile radius of the first two infected trees in Ventura County, close to twenty citrus trees have tested positive for this incurable and fatal sickness. As a result, over half of the affected trees within the Oct. 3 quarantine have already been removed.
Previously, HLB had solely been limited to counties such as Los Angeles, Orange, Riverside, San Bernardino, and San Diego, where more than 6,300 infected trees have been identified and subsequently removed since the disease’s discovery in California in 2012.
The major apprehension among industry professionals and government officials is that the Asian citrus psyllid, a minuscule insect that transmits HLB, could potentially facilitate the disease’s spread to the vast commercial groves of the Central Valley. To combat this threat, authorities have emphasized the importance of maintaining precautions such as not transporting citrus plants, parts, or unclean/untreated fruit from quarantined regions.
Huanglongbing is a bacterial infection that is harmless to humans and animals but devastates citrus trees. Infected psyllids feed on the leaves of citrus trees, leading to the production of bitter, misshapen fruit and, eventually, the tree’s demise. The disease has already wreaked havoc on citrus industries in Florida and Brazil.
California researchers are currently racing against time to find a cure or address the inevitable spread of HLB to the Central Valley. The Asian citrus psyllid has already been discovered in Kern and neighboring counties, further heightening concerns.
Casey Creamer, President, and CEO of the California Citrus Mutual trade group, stressed the industry’s commitment to combatting the disease’s spread. Creamer emphasizes that concerted efforts and cooperation from the public are vital in protecting the entire industry. The most crucial precautionary measure is for individuals to refrain from transporting backyard citrus, especially fruit with stems or leaves. To mitigate the risk, people are advised to ensure their trees remain healthy and free from pests. Unwanted trees should be removed promptly.
Creamer adds, I think everybody has to take it seriously. It’s very easy for this to spread from one area to another if we’re not following the regulations in place to protect the entire industry. It only takes one.
To prevent the further spread of HLB, the California Department of Food and Agriculture established a quarantine in Santa Paula earlier this month. The quarantine prohibits the movement of any citrus nursery stock, host plants, or related items beyond the quarantine zone. However, commercially cleaned and packed citrus can still be transported, while all other fruit must remain within its place of origin, although processing and consumption on the property are permitted. Oranges, lemons, grapefruit, and kumquats are among the citrus fruits encompassed by the quarantine rules.
According to Victoria Hornbaker, director of the CDFA’s Citrus Pest and Disease Prevention Division, the disease’s potential spread via harvest crews, workers, and machinery traveling between the Central Valley and Santa Paula is a significant concern. She highlights ongoing efforts to develop and introduce HLB-resistant citrus varieties, but acknowledges that the process requires time. Scientists not only need to identify the right tree, but its fruits must also meet commercial standards.
Another area of promising research aims to integrate plant material from certain HLB-resistant plants into existing citrus varieties. However, Hornbaker notes that this too will require considerable time.
She remains hopeful, saying, I’m always optimistic that the work we’re doing today will give science the time to catch up and create a cure.
As the battle against HLB continues, it is imperative for everyone to remain vigilant in adhering to regulations and taking necessary precautions. By doing so, we can protect California’s vital citrus industry from further devastation, safeguarding the livelihoods of countless individuals and preserving a cherished part of the state’s agricultural heritage.
