Posts Tagged: huanglongbing
This is one of a series of stories featuring a sampling of UC ANR academics whose work exemplifies the public value UC ANR brings to California.
The coronavirus pandemic has disrupted life for everyone, with information about COVID-19 changing daily. For Californians who aren't fluent in English, obtaining reliable information is particularly difficult. Aparna Gazula, a University of California Cooperative Extension advisor who serves Santa Clara, San Benito and Santa Cruz counties, has been providing COVID-19-related information in Chinese and Spanish for immigrant Bay Area farmers.
In March, when restaurants shut down to curb the spread of the virus, many restaurants and wholesale produce markets cancelled produce orders placed with farmers. Language, cultural differences, low computer literacy and limited access to computers created barriers for small-scale, immigrant farmers in the Bay Area to quickly find new buyers for their perishable produce. Gazula introduced them to food banks, hoping they would accept the produce donations, but the food banks were not set up to pick up donations from small farmers.
Most small-scale farmers lack the financial capital to absorb the revenue shock. To help offset losses from unsold specialty crops, the UCCE advisor and Qi Zhou, the small farm program assistant specialist, have been helping Asian and Latino farmers complete English-language disaster aid applications.
“Since March, we have helped farmers apply for Covid-19-related farmer relief funds,” Gazula said. So far, she said, four of the 17 immigrant farmers who applied to the American Farmland Trust Farmer Relief Fund have received a total of $4,000, and 10 farmers of the 30 who applied to the California Family Farmer Emergency Fund received a total of $42,500.
Recently the U.S. Department of Agriculture expanded the list of specialty crops eligible for its Coronavirus Food Assistance Program to include bok choy, daikon and other vegetables with a deadline of Sept. 11. Communicating by phone and the app We Chat, Gazula and Zhou, who speaks Mandarin, notified local farmers, and advised them how to apply for the disaster funds. Zhou, USDA Natural Resources Conservation Service rangeland management specialist Ling He and another NRCS staff member assisted 64 farmers in completing applications over the past week.
Bob Kuang, president of the Bay Area Chinese Growers Association, shares UCCE information with the association's growers.
“Most of my members don't understand English so they [UC Cooperative Extension] help, like for policy and safety,” Kuang said, providing information the growers can't find elsewhere in Chinese.”
When she was a girl, Gazula saw how hard farmers work to make a living off the land while spending summers and winter breaks at her grandparents' farm in India, where they grew rice, mung beans and chili peppers.
“Farmers are very hardworking people, and small farmers even more so as they manage everything on the farm,” said the small farms and specialty crops advisor. “Their grit, determination to succeed and hardworking spirit truly inspire me.”
“I'd like to help them be successful as much as I can,” she said, “be it research-based information to farm successfully or bilingual support to help them better navigate regulations or apply for grant funds.”
In addition to helping farmers apply for financial relief, Gazula alerted the farmers to shelter in place rules and is delivering COVID-19 safety information about masks, sanitation and social distancing requirements in Chinese and Spanish to them.
“We also helped farmers implement COVID-19-related protocols on their farms,” she said. “We are currently putting together 200 COVID-19 kits that will help farmers comply with worker health and safety-related protocols on their farms. The COVID-19 kits contain reusable masks, hand sanitizer, bilingual Cal OSHA guidelines for employers regarding COVID-19, and a resources sheet listing where to buy the enclosed items.”
When she's not involved in COVID-19 crisis communications, Gazula continues to conduct research on nitrogen uptake in bok choy and bell peppers and irrigation management. She collaborates with Linda Chu, Guo Ping Yuan, Han Qiang Kuang and other Santa Clara County growers who allow the farm advisor to study crops on their farms.
“They do research, like test irrigation systems for right amount of water for the crop and nutrition – fertilizer – for the crop. They do lot of things,” said Bob Kuang, of the Bay Area Chinese Growers Association, who provides land at his farm in Gilroy for UCCE studies.
Gazula also advises farmers on how to implement the Food Safety Modernization Act (FSMA) on their farms and fulfill irrigated land nitrogen reporting. Fines for not complying with regulations can threaten the economic sustainability of small family farms.
Although the majority of growers she works with regularly have limited English and need assistance filing reports to the government, others consult her for production information they can't get elsewhere for the specialty crops they grow. Farmers of Korean, Japanese, Indian and Vietnamese ancestry and others attend meetings to learn the latest research on Asian vegetables such as daikon radish, napa cabbage, bok choy, on choy and various Asian leafy mustard crops including gai choy and pea shoots.
Gazula, who joined UC Cooperative Extension in 2016, currently works with about 180 small-scale growers in San Benito and Santa Clara counties and hopes to expand her outreach to farmers in Santa Cruz County.
To help small farmers adapt to climate change, Gazula and Zhou partnered with UC Agriculture and Natural Resources' Healthy Soils Program staff and Santa Clara County Farm Bureau for technical assistance and held workshops during the winter. Zhou helped the farmers apply for grants from the California Department of Food and Agriculture's State Water Efficiency & Enhancement Program and Healthy Soils Program. The 22 farmers who received CDFA grants brought a total of $424,111 into Santa Clara County.
The outreach work UC Cooperative Extension does wouldn't be possible without the help of bilingual staff such as Zhou, the scientist Gazula hired with grant funds in September, and some translation support from partner organizations and growers as well.
“Relying on partners for translation support isn't practical,” Gazula explained. “Outreach is most effective when it is targeted. It's not just literally translating words, but translating the information the words convey. Because we provide outreach materials to comply with regulations, the language in these materials is very technical and it's important that the information is presented accurately. We also depend on relationships with the farmers to extend the information within their communities. Long-term, it's easier to do outreach with support from our own staff.”
Competition is stiff for money to serve non-English-speaking Californians because the state is home to so many immigrants with different needs. The majority of the grants she uses for outreach are for food safety. The local Open Space Authority, which promotes preserving land for open spaces, has also provided funds for small and beginning farmer outreach and education.
Gazula draws on the expertise of fellow UC Cooperative Extension farm advisors across the state. For example, she said, Richard Smith, who specializes in vegetable production, and Michael Cahn, who specializes in irrigation and water resources, are always willing to help, even though they are not assigned to serve Santa Clara County.
“Farmers already have tremendous challenges when it comes to being successful,” Gazula said. “I feel language barriers and lack of access to the same resources as fluent English-speaking growers shouldn't be the reason they can't farm successfully.”
The recent identification of an Asian citrus psyllid infected with huanglongbing disease in a Riverside commercial citrus grove isn't surprising, said UC Cooperative Extension specialist Monique Rivera in an interview with Brian German of AgNetWest.
"We've had positive trees removed here in Riverside and we're not that far from LA," Rivera said. "Eventually those two quarantine circles are likely to merge here in Southern California."
Rivera said an HLB-infected ACP hasn't been found in Riverside commercial citrus before because CDFA is mainly responsible for sampling ACP in backyard trees. "They aren't looking directly or systematically at commercial groves," she said.
There are resources available for growers to test ACPs found in their citrus orchards. Growers can request PCR testing of ACP or plant samples from an accredited lab, such as the Citrus Pest Detection Program (CPDP) which is operated by the Central California Tristeza Eradication Agency. CDFA will also collect samples for analysis at no cost to the grower.
UC Riverside scientists have found the first substance capable of controlling Citrus Greening Disease, which has devastated citrus farms in Florida and also threatens California.
The new treatment effectively kills the bacterium causing the disease with a naturally occurring molecule found in wild citrus relatives. This molecule, an antimicrobial peptide, offers numerous advantages over the antibiotics currently used to treat the disease.
UCR geneticist Hailing Jin, who discovered the cure after a five-year search, explained that unlike antibiotic sprays, the peptide is stable even when used outdoors in high heat, easy to manufacture, and safe for humans.
“This peptide is found in the fruit of greening-tolerant Australian finger limes, which has been consumed for hundreds of years,” Jin said. “It is much safer to use this natural plant product on agricultural crops than other synthetic chemicals.”
Currently, some growers in Florida are spraying antibiotics and pesticides in an attempt to save trees from the CLas bacterium that causes citrus greening, also known as Huanglongbing or HLB.
“Most antibiotics are temperature sensitive, so their effects are largely reduced when applied in the hot weather,” Jin said. “By contrast, this peptide is stable even when used in 130-degree heat.”
Jin found the peptide by examining plants such as the Australian finger lime known to possess natural tolerance for the bacteria that causes Citrus Greening Disease, and she isolated the genes that contribute to this innate immunity. One of these genes produces the peptide, which she then tested over the course of two years. Improvement was soon visible.
“You can see the bacteria drastically reduced, and the leaves appear healthy again only a few months after treatment,” Jin said.
Because the peptide only needs to be reapplied a few times per year, it is highly cost effective for growers. This peptide can also be developed into a vaccine-like solution to protect young healthy plants from infection, as it is able to induce the plant's innate immunity to the bacteria.
Jin's peptide can be applied by injection or foliage spray, and it moves systemically through plants and remains stable, which makes the effect of the treatment stronger.
The treatment will be further enhanced with proprietary injection technology made by Invaio Sciences. UC Riverside has entered into an exclusive, worldwide license agreement with Invaio, ensuring this new treatment goes exactly where it's needed in plants.
“Invaio is enthusiastic to partner with UC Riverside and advance this innovative technology for combating the disease known as Citrus Greening or Huanglongbing,” said Invaio Chief Science Officer Gerardo Ramos. “The prospect of addressing this previously incurable and devastating crop disease, helping agricultural communities and improving the environmental impact of production is exciting and rewarding,” he said. “This is crop protection in harmony with nature.”
The need for an HLB cure is a global problem, but hits especially close to home as California produces 80 percent of all the fresh citrus in the United States, said Brian Suh, director of technology commercialization in UCR's Office of Technology Partnerships, which helps bring university technology to market for the benefit of society through licenses, partnerships, and startup companies.
“This license to Invaio opens up the opportunity for a product to get to market faster,” Suh said. “Cutting edge research from UCR, like the peptide identified by Dr. Jin, has a tremendous amount of commercial potential and can transform the trajectory of real-world problems with these innovative solutions.”
UC Cooperative Extension developed an online interactive map that allows Californians to see how close they live to citrus trees infected with huanglongbing disease, reported Jeanette Marantos in the Los Angeles Times. This information is critical for the more than 60% of Californians who are growing their own backyard orange, grapefruit, mandarin, lime and other citrus trees.
Huanglongbing is an exotic citrus disease that kills every tree it infects. An exotic insect, the Asian citrus psyllid, spreads the disease from tree to tree. If the disease makes its way into California's commercial citrus production regions, it threatens the state's valuable and iconic citrus industry.
Go to http://ucanr.edu/hlbapp and type in your address. If you are inside the red circle — within two miles of a hot zone — UCCE suggests you remove your citrus trees and plant different types of fruit trees, such as peaches, pears, apples or figs, until researchers find a cure. In the yellow circle — within two to five miles of a hot zone — consider replacing your tree with a non-citrus fruit tree or protect your citrus trees. Find detailed information on home citrus management here https://ucanr.edu/sites/ACP/Homeowner_Options/
“When we first started this program back in 2012, I was encouraging Master Gardeners to teach homeowners how to treat their trees [to discourage psyllids, which are the insects that spread HLB],” she said, “but the complaint came back from the Master Gardeners, ‘I treat my trees but none of my neighbors do, so what's the point?'” said Beth Grafton-Cardwell, UC Cooperative Extension entomology specialist and director of the Lindcove Research and Extension Center in Exeter.
Grafton-Cardwell said the threat is serious. HLB disease devastated Florida's citrus industry when it hit in 2005, destroying half of its acreage and production, and pretty much eliminating residential citrus.
The battle against the psyllid in California is being helped by the introduction in 2011 of Tamarixia radiata, a parasitic wasp native to Pakistan, by UC Cooperative Extension biological control specialist Mark Hoddle and his entomologist wife Christina Hoddle.
"We've had psyllid here [in California] since 2008, but we still have a lot of oranges,” Hoddle said. “The disease hasn't swept through California the way it did through Florida, and I believe our biological control program is why. Psyllid populations have decreased by 70% to 80% since our first parasite release in 2011. We haven't wiped out HLB in citrus trees, but we have mitigated the risk.”
Central Valley residents from Visalia to Sacramento look forward every year to the beginning of strawberry season in early April, when roadside strawberry stands operated by Hmong and Mien farmers open to the public.
These farms grow strawberry varieties such as Chandler and Camarosa that haven't traded flavor for shelf life – they don't ship or store well, but they are far sweeter than varieties usually sold in stores, and they reach their peak ripeness and flavor in the fields next to the strawberry stands.
As strawberry season opens this year, farmers are hoping that customers will still stop by the stands to pick up their fresh, seasonal strawberries, and also that they will observe 6-foot social distancing and other guidelines to reduce the spread of COVID-19. UC Cooperative Extension agricultural assistant Michael Yang and I were interviewed on a local news station to encourage Fresno residents to practice these guidelines while supporting local farmers.
To assist Fresno strawberry farmers, the UCCE small farms team in Fresno County developed, printed, and distributed signs for roadside strawberry stands reminding customers to observe social distancing and other safety practices, as well as guidelines for farm stands to reduce the spread of COVID-19. Versions of the signs were also developed for strawberry stands in Merced and Sacramento, as well as a general sign for local produce at any farm stand.
Signs and safety guidelines were printed with funding from the Western Extension Risk Management Education Center, and Michael Yang distributed large printed versions of the signs to all strawberry stands on the Fresno County Fruit Trail map in Fresno County. These materials have also been shared with UCCE small farms and food systems advisors as well as nonprofit and agency partners and county Agricultural Commissioner's offices, and they are available for printing on the UCCE Fresno strawberry website.