The California citrus industry—made up of 3,500 growers in Ventura, Riverside, and the San Joaquin Valley, and encompassing 70-75 packing houses—is an agricultural facet that continues to make California a fresh citrus powerhouse. Joel Nelsen, President and CEO of the California Citrus Mutual, spoke to California Ag Today recently on the industry-wide issue of Huanglongbing Disease—a deadly disease that has threatened the industry in every part of the state.
“For our industry, it’s a combination of enthusiasm, unity, frustration, and aggravation because we continue to fight the spread of the disease in Southern California.”
“We’re continually frustrated because science has not yet found a cure. We’ve given the scientific community an average of thirty to forty million dollars a year to find a cure for this disease.”
In a recent study done by the University of California, Riverside, economic outputs of the citrus industry is roughly $7 billion.
“It’s an economic engine for certain parts of this state. Lose it, and it’s not a positive alternative, that’s for sure,” Nelsen said.
California Ag Today recently interviewed Joel Nelsen, president and CEO of the California Citrus Mutual. He spoke on his recent trip to UC Riverside about the Citrus Health Response Program. While speaking with USDA, they discussed the game plans that will be used to battle Huanglongbing (HLB) disease, which is vectored by an invasive insect called Asian Citrus Psyllid.
“We got into it, which I thought was an interesting discussion. What would growers do if in fact HLB was discovered in a grower’s orchard and what would the be obligated to do,” Nelsen said.
“And what came out of that discussion is that we are going to work with the USDA. We’re going to develop a war game scenario. We’re going to bring people into a room and start talking about it, just to see what the reactions were, and we’re going to challenge these individuals to do what needs to be done,” Nelsen explained. “We’re just going to have to figure out how best to address the industry and areas like this.”
Nelsen said that they discussed whether or not there was enough being done in that partnership with the homeowner. “We came to the conclusion that no, quite frankly the industry has been carrying that ball and that USDA and CDFA can do a little bit more in their role as government”
Tree removal and beneficial insects were also discussed.
“We talked about the continued trees being removed, and everybody was satisfied about that. We talked about whether or not beneficial insects can help in this situation. Surprisingly, the answer was pretty much no,” Nelsen explained. “Beneficial releases may help in an urban environment to a small extent, but from a commercial standpoint, it doesn’t help. So there were a lot of discussions, some debate, and most of all, some camaraderie that was developed as far as going forward.”
Nearly 400 trees in front and back yards of homes have been destroyed due to testing positive to HLB disease.
“They’re all in a clearly defined geographical area in Southern California,” Nelsen said. “So what we have is a lot of backyard adventures that bring in rootstock that unfortunately was diseased, and as a result of that, those individuals are the ones that are seeing problems associated with their own trees.”
California Ag Today recently spoke with Jim Adaskaveg, professor of plant pathology at UC Riverside. He’s a plant pathologist, microbiologist and epidemiologist. He discussed the importance of protecting walnut trees from walnut blight.
Adaskaveg explained how walnut blight is problematic due to the higher rainfall in the northern part of the state.
“We’ve been working on this for a number of years, and overall, the northern part of the state is always higher at risk because of the higher rainfall in Glenn County,” he said. “There is much higher risk for disease in Northern California, so a lot of the growers have planted later blooming varieties such as Chandler to avoid the blight infections.”
“Rick Buchner [at UC Cooperative Extension] Tehama County and his group called that the prayer stage, which is when the female flower becomes exposed as it emerges from the bud. Those two timings would be for high disease pressure. If you had a history of the disease and you know that the disease is in your orchard, then we would suggest that timing,” Adaskaveg said.
“If you don’t have disease, and you still want to protect yourself, we say just spray at the pistillate flower emergence or the prayer stage. That sets a good way to initiate the spray program,” Adaskaveg explained.
Growers must keep in mind canopy expansion when applying materials.
“Walnuts are big trees, and as they go through bloom, all the leaves started emerging almost weekly. The tree canopy in that first three weeks of the season is doubling in size. By the time you get three or four weeks after that, the catkin flowering trees in full canopy will require a reapplication of materials,” Adaskaveg said.
The Citrus Research Board (CRB) recently held their annual California Citrus Conference in Exeter, bringing together a variety of guest speakers and research presentations. The Conference focused on pressing Asian Citrus Psyllid (ACP) and Huanglongbing (HLB) issues, along with political action updates and current projects that are important to the citrus industry. Gary Schulz, president of the CRB, said “We have a 21-member board and we’ve been planning this event for the last 12 months. It’s been 4 years since we held the last conference,” noted Schulz.
The CRB is responsible for overseeing the California Citrus Research Program (CCRP), a grower-funded and grower-directed program created in 1968 under the California Marketing Act. The CCRP’s purpose to enable California’s citrus producers to sponsor and support research that furthers the overall industry. Therefore, close to 70 percent of the CRB’s overall budget is allocated to research.
Schulz said the Conference “was a great, great day to have a good update on some of the dollars the Citrus Research Board has been spending on the growers’ behalf on research.” Schulz explained HLB represents the single greatest threat that citrus growers have faced worldwide.
For the past seven years, the USDA and Congress have allocated between $10 and $12 million dollars annually for ACP and HLB research operations. Advocacy groups and other supportive ag organizations have contributed the difference to reach an annual ACP and HLB research budget of close to $90 million dollars a year. We fund a lot of UC Riverside and USDA agricultural research, service researchers, plus research at UC Davis and the University of Arizona,” Schulz noted.
Schulz, who has many years of experience in California agriculture, having served as general manager of the Raisin Administrative Committee and CEO of the California Raisin Marketing Board, stated that CRB has a great working relationship with California Citrus Mutual (CCM). “Joel Nelson and CCM have worked very hard with the packers to assess themselves, put together a private foundation, and work with the university,” Schulz said.
Featured Photo: Adult Asian Citrus Psyllid (Source: The Citrus Pest & Disease Prevention Program)
The UC Cooperative Extension Program has served Tulare County since 1918 and continues to meet the ever-changing needs of the community. UC Cooperative Extension, Tulare County is preparing to welcome their new citrus farm advisor, Greg Douhan, on March 1, 2016. Douhan, who noted his excitement for the opportunity, will be taking the reins from the recently retired Neil O’Connell who gave over 34 years of faithful service advising Tulare County citrus growers.
Douhan shared that his relatives inspired him to focus his career in agriculture. “I had an uncle who was an almond grower when I was a kid. And my grandfather was an avid horticulturalist; he used to graft different trees and I always found that fascinating.”
“As I got older, I decided I was interested in plants, so I went to Humboldt State University. I also got interested in fungi, so I decided to fuse my interests in fungi and in plants and go into plant pathology,” Douhan said.
“I earned my Master’s and Ph.D. at Washington State University, and then completed a post-doc assignment at UC Davis for 3-4 years. I moved to UC Riverside for about 6 years. Now I am here in Tulare County!”
Cooperative Extension advisors serve as conduits of information from various UC campuses. Subject matter specialists, along with local research centers, collaborate with local advisors to identify and solve local problems through research and educational programs. The mission of the program is to serve California through the creation, development and application of knowledge, in agriculture, natural and human resources. Farm advisors then apply this knowledge to improve our agriculture and food systems along with our natural resources and environment.
“I’ve been working for the UC system basically since I was a post-doc,” Douhan said, “so it has been for many years. I think Cooperative Extension was the best system for working with both the growers and everybody else to better California agriculture,” Douhan said. “This was just an incredible opportunity. I was doing science and looking for another career move, and this was a perfect opportunity to have a next chapter in doing something different.”
John Kabashima wrapped up his horticultural career on July 1, after 28 years with University of California Agriculture and Natural Resources. Nursery professionals lauded the UC Cooperative Extension advisor’s service to the nursery and landscape industry and to homeowners in Orange and Los Angeles counties.
“He’s one of the few people who could translate science into business with a sense of candor and fact-based conversation,” said Robert Crudup, president of Calabasas-based Valley Crest Tree Company, of Kabashima.” John has long-term vision, which he used throughout his career to move the nursery industry forward.”
“He is smart about political science as well as plant science,” Crudup said. On a regular basis, Kabashima would warn growers about emerging issues that were likely to affect the nursery industry, such as regulations to control the spread of polyphagous shot hole borer, red imported fire ant and palm borer.
“He’s been very, very valuable,” said retired nurseryman Gary Hayakawa, noting that Kabashima not only contributed research on pest control and water issues for the nursery and landscape industries, but also persuaded people from UC campuses, the California Department Food and Agriculture and industry to work together. “Before he was involved in issues, the work was all separate. Industry didn’t have input,” Hayakawa said. “What John has done is to work with all three to form a coalition.”
Crudup, whose company has nursery operations in Los Angeles, Ventura, Alameda and San Joaquin counties, agreed.
“John’s biggest contribution was his work with the glassy-winged sharpshooter subcommittee,” said Crudup, who served on the subcommittee. “He brought a voice of reason that helped counterbalance emotional sides of the discussion.”
“His ability to act as the primary liaison between the nursery industry, CDFA, the UC, the county agricultural departments and the wine and grape industries was the primary reason this part of the GWSS (glassy-winged sharpshooter) program was so successful and, more importantly has resulted in the continued viability of the California nursery industry in light of significant regulatory pressures,” said Bob Wynn, who was statewide coordinator of the CDFA Pierce’s Disease Control Program and who continues to oversee the program as senior advisor to Secretary Karen Ross.
“The CDFA, with advisement and counseling from John, developed what is known as the Approved Nursery Treatment Program, which allows nurseries in the infested areas of the state to ship by merely treating the plants with an approved treatment,” Wynn said. “John was the primary author in the development of the nursery ‘Approved Treatment Best Management Practices’ document published in 2008. The use of this document has allowed the nursery industry to save millions of dollars in regulatory compliance costs over time.”
A native of Los Angeles, Kabashima says he started working in his family’s nursery business as soon as he was tall enough to water 1-gallon nursery plants. “After killing thousands of plants, I was finally allowed to manage the family business from 1970 to 1976,” he quipped.
In 1976, his family sold the nursery and Kabashima enrolled at California Polytechnic University, Pomona. After he earned a B.S. in agricultural biology from Cal Poly Pomona in 1979, he was hired by UC Riverside horticulture entomologist Pat Morishita as a lab technician. While working at UC Riverside, Kabashima earned a master’s degree in pest management. He would later complete a Ph.D. in entomology at UC Riverside.
Kabashima earned his MBA at Pepperdine University in 1986 while managing the Ornamental Horticulture Division at Target Specialty Products. In 1987, the UC Division of Agriculture and Natural Resources recruited him to become a UC Cooperative Extension environmental horticulture advisor in Orange and Los Angeles counties.
Over the years, he has studied the management of insects, diseases and weeds in horticulture production systems, biological control of exotic pests, and water-related problems in landscapes, golf courses, nurseries, municipalities and watersheds.
In 1998 Kabashima took over the fledgling UC Master Gardener Program in Orange County, which as of now has trained more than 300 UC Master Gardener volunteers to extend research-based information on gardening and horticulture to the public.
In 1994, when Orange County filed for bankruptcy and the Board of Supervisors voted to discontinue funding and housing for the local UC Cooperative Extension, Kabashima worked with Gary Hayakawa to keep UCCE in the county.
“When Orange County cut Cooperative Extension’s budget, we found out that without extension you don’t have 4-H or Master Gardeners,” Hayakawa said. To preserve the UC Cooperative Extension programs, Hayakawa, who was an Orange County Fair Board member, helped Kabashima secure office space in trailers on the fairgrounds. In 2014, the UCCE office moved from the fairgrounds to UC ANR South Coast Research and Extension Center in Irvine.
Kabashima belongs to many professional organizations including the Entomological Society of America, California Association of Nurseries and Garden Centers, Nursery Growers Association, Western Chapter of the International Society of Arboriculture, United Agribusiness League, and San Diego Flower and Plant Association. The scientist has served on numerous government and industry advisory committees.
Throughout his career, Kabashima’s achievements in education and research have been recognized by various organizations. To name a few, he received the 1987 Education and Research Award from the Orange County Chapter of the California Association of Nurseries and Garden Centers (CANGC), 1993 CANERS Research Award from CANGC, 2002 Nursery Extension Agent Award from the American Nursery and Landscape Association, 2008 Western Extension Directors Award of Excellence, 2010 Entomological Society of America’s National IPM Team Award and the 2011 California Agriculture Pest Control Advisors Association Outstanding Contribution to Agriculture Award. In 2014, he and his friend Hayakawa were inducted into the Green Industry Hall of Fame.
Being a UCCE advisor has suited Kabashima. “I love learning new things, sharing that information with others, and using my skills to solve problems facing California, such as the ever-increasing arrivals of exotic and invasive pests,” he said. The avid photographer has been able to unite his avocation with his vocation. His photographs of insects have been used to illustrate textbooks, websites and news articles.
“Success in one’s field is often a combination of natural ability, informal and formal training and education, being mentored, and networking with collaborators and colleagues, all sprinkled with a little bit of luck and support from one’s family and friends,” Kabashima said.
In retirement, Kabashima plans to seek new culinary experiences with his wife Janet and daughter Misa, at home and in their travels together. He has been granted emeritus status by UC ANR and he will continue his efforts to help UC Irvine save trees on its campus that are infested with polyphagous shot hole borer.
UC Agriculture and Natural Resources researchers and educators draw on local expertise to conduct agricultural, environmental, economic, youth development and nutrition research that helps California thrive. Learn more at ucanr.edu.
The United States Department of Agriculture (USDA), working in coordination with California agricultural officials, TODAY declared the Red Palm Weevil eradicated from the Laguna Beach area of Orange County. The weevil was first detected by a local arborist in October 2010 in a Canary Island date palm tree in a residential area of Laguna Beach.
The Red Palm Weevil is considered to be one of the world’s most destructive pests of palms and an infestation typically results in the death of the tree. In an effort to make the local community aware of this invasive species, the USDA, the California Department of Food and Agriculture (CDFA), and the Orange County Agricultural Commissioner teamed-up with specialists from the University of California, Riverside, and UC Cooperative Extension to work closely with residents, local community officials and arborists.
“This pest is a serious threat to our nursery growers and palm date farmers,” said CDFA Secretary Karen Ross, “It endangers all of the decorative palms that are common in our landscape and part of the classic California image. A special thank you goes out to the local arborist who originally reported this pest. That gave us a valuable head-start.”
According to international standards, a three-year period free from any Red Palm Weevil detections is necessary to declare eradication. This standard was met as the last confirmed detection of RPW occurred on January 18, 2012.
The weevil is native to Southeast Asia and has spread throughout the Persian Gulf. It is found in parts of Asia, Africa, the Middle East, Europe, Papua New Guinea, and Solomon Islands. Prior to the detection in Orange County, the closest confirmed infestation to the United States was in the Dutch Antilles.
Female Red Palm Weevils bore into a palm tree to form a hole into which they lay eggs. Each female may lay an average of 250 eggs, which take about three days to hatch. Larvae emerge and tunnel toward the interior of the tree, inhibiting the tree’s ability to transport water and nutrients upward to the crown. Early symptoms of weevil infestation are difficult to detect because the entry sites can be covered with offshoots and tree fibers. In heavily infested trees, fallen pupal cases and dead adult weevils may also be found around the base of the tree.
If residents suspect an infestation, they are encouraged to call the CDFA Pest Hotline at 1-800-491-1899 or contact their local county agricultural commissioner.
(Photo credit: UC Riverside Center for Invasive Species Research)
Two portions of San Joaquin County have been placed under Asian citrus psyllid (ACP) quarantine following detections of one ACP within the City of Manteca and one within the City of Lodi. The quarantine zone in Manteca measures 105 square miles and in Lodi it measures 95 square miles.
The quarantine prohibits the movement of citrus and curry tree nursery stock out of the quarantine area and requires that all citrus fruit be cleaned of leaves and stems prior to moving out of the quarantine area. An exception may be made for nursery stock and budwood grown in USDA-approved structures that are designed to keep ACP and other insects out. Residents with backyard citrus trees in the quarantine area are asked not to transport citrus fruit or leaves, potted citrus trees, or curry leaves from the quarantine area.
The ACP, a tiny (0.125 in. length) mottled brown insect that is about the size of an aphid, is an invasive species of grave concern because it can carry the disease huanglongbing (HLB), also known as citrus greening. All citrus and closely related species such as curry trees are susceptible, and there is no cure. Once infected, a diseased tree will decline in health with yellowing shoots, asymmetrical leaf mottling and abnormally shaped bitter fruit until it dies—typically within three years. HLB was detected once in California, in 2012, on a residential property in Hacienda Heights, Los Angeles County. This plant disease does not affect human health.
Residents in the area who think they may have seen ACP or symptoms of HLB on their citrus trees are urged to call CDFA’s Pest Hotline at 1-800-491-1899. For more information on the ACP and HLB, please visit: www.cdfa.ca.gov/go/acp
The University of California Agriculture and Natural Resources’ Integrated Pest Management (IPM) Program has developed treatment guidelines for citrus growers within the quarantine zones. A general principle when applying insecticides to control ACPs in commercial citrus is that no one insecticide fully controls ACP across all life stages because:
The UC IPM Guidelines for Citrus provides a ranked list of insecticides that are effective against the Asian citrus psyllid with the pesticides having the greatest IPM value listed first—the most effective and least harmful to natural enemies, honeybees, and the environment are at the top of the table.
According to Mark Hoddle, UC Riverside (UCR) Director, Center for Invasive Species Research, “The science of biological control, the use of a pest’s natural enemies to suppress its populations to less damaging densities,” shows promise against the ACP with releases over the last three years of Tamarixia radiata–a parasitic wasp from Pakistan–in urban areas of southern California. Thus far, this natural ACP enemy helps to control ACP growth in residential areas, but is inadequate for commercial application.
Harry Scott Smith was the first to use the phrase “biological control” in 1919 at the meeting of Pacific Slope Branch of the American Association of Economic Entomologists at the Mission Inn in Riverside. Smith worked on the biological control of gypsy moth with USDA, then moved to the University of California Riverside where he eventually created and chaired the Department of Biological Control, which offered the only graduate degree in biological control in the world.
The Harry Scott Smith Biological Control Scholarship Fund at UCR aims to attract the brightest students to study biological control by providing assistance to its students to attend conferences to present their research or to participate in training workshops. More information on the Scholarship, past awardees, and a list of donors can be reviewed on the website.
Sources: CDFA; UC IPM; UC Riverside (UCR); UCR Center for Invasive Species Research; USDA Animal and Plant Health Inspection Service (APHIS)
By Kyle Buchoff, California Ag Today Reporter
Nematodes are generally harmless, tiny roundworms found in the soil. However, the root-knot nematode, which lives in hotter climates such as in the Central Valley, can inflict havoc on crops, especially vegetables.
J. Ole Becker, Extension Specialist of Nematology at UC Riverside, described the big problems these tiny organisms create for growers, “Nematodes are an underestimated disease problem. They are probably costing California agriculture at least $1.5 billion each year in lost production. Our major problem is root-knot nematodes; we have four or five species causing problems throughout the state.”
Root-knot nematodes were named due to the way they entwine themselves around the root of the plant, which can dramatically decrease the plant’s yield. Becker explained that tools and strategies available to growers minimally affect crops and the environment, “We now have second and third generation products entering the market that are as effective, but much less toxic, then what was available twenty years ago. They also have shorter entry time.”
According to the UC Riverside Department of Nematology website, millions of species of nematodes cover all seven continents, but only a small fraction affect our food supply.