It's not just humans who are battling a life-threatening and devastating illness. For nearly 15 years the U.S. citrus industry has been fighting its own relentless disease—huanglongbing—through measures reminiscent of those we're using to prevent the spread of COVID-19: quarantine, cleanliness, and travel restrictions.
More commonly known as HLB or citrus greening disease, huanglongbing is caused by a bacterium that attacks citrus tree roots and leads to asymmetrically shaped, unripe fruit with bitter juice. It can kill a citrus tree in five to eight years, according to the University of California Integrated Pest Management Program, and there's no known cure.
The disease is spread by the Asian citrus psyllid, a tiny insect that carries HLB and feeds on citrus leaves, infecting the plant while it eats.
Together, Asian citrus psyllid and HLB have spread rapidly throughout several states in the U.S., most notably Florida, where 90 percent of the state's citrus groves were infected with HLB by 2019. Asian citrus psyllid first reached Southern California in 2008, and, according to the UC Integrated Pest Management Program, the pest is making its way north.
That's a problem for California's multi-billion-dollar citrus industry, and to slow the spread of the disease, various regions of the state are cut into quarantine zones. According to state regulations, citrus can only travel in and out of those regions once it's been thoroughly cleaned or sprayed with pesticides.
- Photo By Kasey Bubnash
- AUTOMATED Bee Sweet Citrus unveiled on June 12 its new SLO County-based citrus wash line and processing facility, which can wash and organize 70 bins carrying 800 pounds of fruit each in an hour.
For years, citrus growers on the Central Coast have gone without a real packing facility where harvested fruit can be washed and organized en masse. Instead local farmers have been using pesticides to rid their products of possible infestations before transportation.
But on June 12, Bee Sweet Citrus, a prominent citrus packing and shipping company with groves throughout California, unveiled its new SLO County-based citrus wash line and processing facility, an almost entirely automated line that removes the leaves from recently harvested fruit, washes it in recycled and filtered water, and then sorts it by type, color, and maturity. The 14,900-square-foot facility is the first of its kind on the Central Coast—no others exist in SLO or the five surrounding counties—and it's expected to reduce SLO County's pesticide use by at least 700,000 gallons each year.
"We really don't like to have to spray every time we harvest," Bee Sweet Citrus founder Jim Marderosian said at the June 12 unveiling.
As a year-round, international organization, Bee Sweet Citrus grows citrus in various parts of California and then ships product throughout the U.S., Europe, Australia, New Zealand, and the Pacific Rim. Without a citrus packing and washing facility on the Central Coast, crops grown and harvested in SLO County have to be sprayed with pesticides before they're transported to other regions.
Other farmers in the region struggle with same issue. In 2017, roughly 64,200 pounds of pesticides were used on citrus crops in SLO County, according to data collected by the California Department of Pesticide Regulation. More than 180,000 pounds of pesticides were used on Santa Barbara County crops.
Marderosian hopes his wash line will help reduce those numbers.
Located on Bartleson Ranch in Nipomo, a 450-acre avocado and lemon orchard entrusted to Cal Poly, the new state-of-the-art citrus wash line was developed in partnership with Cal Poly's College of Agriculture, Food, and Environmental Sciences, and will double as a way for students to learn about pest management, agricultural technology, and engineering locally.
Washing the fruit is a simple enough idea, but Marderosian said the technology used to do so isn't, and neither was the facility development process, which he said took about two years total. Although Marderosian wouldn't say exactly how much the wash line facility cost, with the land, permitting, technology, and materials required, it was a major investment.
But because it will be available for use by students and other citrus farmers in the area, it was well worth the effort.
"We didn't just build it for ourselves," Marderosian said.
While citrus crops have always existed in SLO County, the industry is slowly becoming more popular locally, according to Russ Kabaker, Cal Poly's assistant dean of advancement and external relations in the College of Agriculture.
"You've got wine grapes coming out and lemons going in," Kabaker said.
While lemons were SLO County's 13th most valuable crop in 2012, worth about $9 million, they reached 10th place by 2018, when SLO County's lemon industry was valued at about $24.5 million according to the SLO County Department of Agriculture crop reports.
While lemon trees grown in other parts of the state yield a single harvest every year, trees on the coast produce full-grown lemons multiple times a year.
So as big citrus producers grapple with Asian citrus psyllid in other parts of the nation and Southern California, Kabaker said he and others in the agricultural industry expect many to move portions of their operations to the Central Coast.
The new Bee Sweet Citrus wash line—which, according to Cal Poly, can process 70 bins carrying 800 pounds of fruit each in an hour—is built with the capacity to handle that kind of uptick, he said.
"This many lemons," Kabaker said, pointing to the wash line as it quickly dumped thousands of lemons in water and organized them by maturity in seconds, "with this few people is pretty amazing."
Another benefit, of course, is that Cal Poly students won't have to travel to the San Joaquin Valley to see how citrus is washed in a large packing facility. And, Kabaker said, it'll be nice to reduce the use of pesticides on Cal Poly's citrus crops.
Pesticides kill all organisms living on a plant and in its soil, the good and the bad, which Kabaker said is less than ideal in a classroom setting where students are supposed to be learning about and studying those organisms.
"We didn't want to spray," he said. "I think [this] is a good project." Δ