Breeding for Pierce’s Disease Resistance Has Sped Up

Traditional Breeding Helps Find Resistance to PD

By Patrick Cavanaugh, Farm News Director

The glassy-winged sharpshooter is a major vector of Pierce’s Disease, which kills grape vines. Pierce’s Disease devastated the grape industry in southern California and lead to the creation of the Pierce’s Disease/Glassy-Winged Sharpshooter Board (PD/GWSS Board). Government programs to fund research on glassy-winged sharpshooters and Pierce’s Disease invest nearly $20 million annually.

California Ag Today recently spoke with Ken Freeze, the outreach and education director for PD/GWSS. He told us about two major methods of control and prevention that the board is funding.

“There’s the area-wide control program, which does everything it possibly can to pretty much keep the glassy-winged sharpshooter confined to basically the southern part of the state,” Freeze said.

This control program prevents the further spread of Pierce’s Disease into other parts of the state, which could devastate wine growers. In addition to preventing the further spread of Pierce’s Disease, the board is also funding additional research into hopefully finding a cure.

“We’ve got UC Davis Genetics Professor Andy Walker working on Pierce’s Disease resistant grapevine before the program, and he just released some of those vines to the UC Davis Foundation Plants Services.”

Freeze said this development has been done through traditional breeding, with the assistance of some new technology.

Walker’s traditional breeding is sped up by a lot of high tech tools. Previously growers would crossbreed, however they’d have to infect the vine and see if it got Pierce’s Disease.

“That could take a year or two. Now they know the genetic markers, so when the plant has only two or three leaves on it, researchers pull a leaf, do a DNA track on it, and look for that marker,” Freeze explained. “Depending on the marker, the vine either goes to the next step in breeding or it ends up in the trash heap. So that has just sped up that process incredibly.”

“Again, that’s all just using traditional breeding,” Freeze said.

California Ag Today2021-05-12T11:05:15-07:00December 4th, 2017|

Modifying Rootstocks to Fight, Prevent Pierce’s Disease

Scientists Help Grapevines Double-team Pierce’s Disease

By Patrick Cavanaugh, Farm News Director

The glassy-winged sharpshooter is a flying insect that vectors a fatal grapevine malady known as Pierce’s Disease. Scientists are conducting volumes of research to fight this insect and reduce disease infection on vines. Moreover, scientists are studying methods to prevent the spread of Pierce’s Disease on winegrapes in California entirely.

California grapevine

Ken Freeze is the outreach coordinator for the California Department of Food and Agriculture (CDFA) Pierce’s Disease Glassy-winged Sharpshooter Board (PD/GWSS) as well as an account director at Brown-Miller Communications. On behalf of the PD/GWSS Board, Freeze communicates with winegrape growers who pay the Board an assessment to conduct research. Freeze explained ongoing research and how research funds are being spent.

FIGHTING PIERCE’S DISEASE

Could introducing pectin into grapevines, help prevent that bacteria, Xylella fastidiosa, from entering the vine? Freeze said, in a recent field trial, “scientists found five different genes that when placed in a rootstock, put either a molecule or a protein up into an unmodified scion that in one way basically stops the bacteria from moving around,” he said.

“For instance, one of the genes comes from the pear,” said Freeze. “I think we’re all familiar with pectin. A lot of plants produce pectin naturally; grapevines are not one of them. By modifying a rootstock with this pear gene, when the bug comes and injects the bacteria into the plant, the pectin literally gums it up and it can’t move around.”

An unmodified plant injected with bacteria by the glassy-winged sharpshooter, turns to another strategy. “When the bacteria population reaches a certain point, [the plant] releases a protein that causes the bad bacteria to stop moving around. However, in grapevines, it is too late when that signal comes; the plant is already dead. By modifying the rootstock to automatically generate that same protein when the bacteria enters the plant, the bacteria shuts down,” said Freeze.

Winegrapes

Freeze said scientists are seeing that these strategies are working quite well. “What scientists are actually doing now is stacking these genes, two by two, in the rootstock. Now each root will produce two different ways to shut down the bacteria. If for some reason in the future the bacteria figures out a way to overcome one of those ways, chances are it won’t figure out how to overcome both of them.”

PREVENTING PIERCE’S DISEASE

Dr. Andy Walker, a UC Davis professor and geneticist in the Department of Viticulture and Enology, has been working for years on rootstock that could block Pierce’s Disease from entering the vine. “He’s already released 14 different varieties to the Foundation Plant Services as well as three different rootstock that are resistant to Pierce’s Disease,” said Freeze. “The best varieties will be released to nurseries probably next year. Then from there [nurseries will] basically start growing them and taking orders from winegrowers.”

Freeze noted that other field trials are continuing. “We have field trials for a benign strain of Pierce’s Disease. It is like giving plants a smallpox vaccination, only it is the bacteria. That is on its way to commercialization. In the future, you might actually order your new vines from the nursery pre-infected with the bacteria that would normally cause [Pierce’s Disease]. But in this case, it will not cause it,” said Freeze.

CDFA Pierce’s Disease Glassy-winged Sharpshooter Board (PD/GWSS)

CDFA Pierce’s Disease Glassy-winged Sharpshooter Board (PD/GWSS) Interactive Forum

CDFA Pierce’s Disease Control Program

UC Davis Department of Viticulture and Enology

UC Davis Foundation Plant Services

California Ag Today2021-05-12T11:02:00-07:00December 2nd, 2016|

Jamming Leafhopper Signals

Jamming Leafhopper Signals to Reduce Insect Populations that Vector Plant Disease

By Patrick Cavanaugh, Farm News Director

An innovative team of researchers at the San Joaquin Valley Agricultural Sciences Center, USDA Agricultural Research Services (ARS) in Parlier Calif., are trying to confuse leafhopper communication in hopes of reducing certain devastating plant diseases. Of particular interest is the glassy-winged sharpshooter, a large leafhopper that can vector or spread the bacteria Xylella fastidiosa from one plant to another which causes devastating plant diseases such as Pierce’s disease in grapes and almond leaf scorch.

Dr. Rodrigo Krugner, a research entomologist on the USDA-ARS Parlier team since 2007, explained, “We started on this glassy-winged sharpshooter communication project about two years ago. These insects use substrate-borne vibrations, or sounds, to talk to, identify and locate each other; actually do courtship; and then mate,” Krugner said.

Click here to hear LEAFHOPPER SOUNDS!

Glassywinged Sharp Shooter

“This area of research started probably 40, or 50 years ago with development of a commercially-available laser doppler vibrometer (LDV), a scientific instrument used to make non-contact vibration measurements of a surface,” Krugner said. “Commonly used in the automotive and aerospace engineering industries, the LDV enabled an entomologist to listen to and amplify leafhoppers communicating,” Krugner said. “We’ve been doing recordings in the laboratory, learning about their communication with the idea of breaking, or disrupting, that communication. Once we disrupt that, we can disrupt mating and thereby reduce their numbers in vineyards and among other crops.”

Krugner noted the research team is evaluating two different approaches: one is to discover signals that disrupt their communication, and the other is lure them away from crops or towards a trap. “We may be looking at female calls, for example. An analogous system would be the pheromones, or long-range attraction volatile chemicals released by female lepidoptera, to attract males.” However, since leafhoppers use only sound, Krugner said, “We’re trying to come up with signals to disrupt their mating communication. We’re also looking at signals to jam their frequency range, 4000-6000 Hz, so they cannot hear each other,” Kruger said. “We’re also looking at signals that can be used to aggregate them, or lure them, into one section of a crop, or maybe repel them from the crop. These are all different approaches that we’re investigating right now.”

Krugner explained, “Researchers are attempting to perfect the disruptive sounds in order to do the things we need—to actually implement a management strategy for disrupting not only glassy-winged sharpshooter, but anything in a vineyard that actually communicates using vibrational communication. We know what they are saying to each other, which is very important. In the laboratory, the signals that we have look promising in disrupting the communication of these insects, so we’re taking them into the field.

Current mating disruption trials are underway in Fresno State vineyards. “We’re going to finish that research, hopefully, next year,” said Krugner, adding, “usually, fieldwork takes two to three years to show something.”

(Featured photo: Rodrigo Krugner, research entomologist, USDA-ARS, Parlier)

California Ag Today2021-05-12T11:05:49-07:00August 15th, 2016|

UC ANR Horticulture Advisor Retires After 28 Years

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.”

John Kabashima, UC ANR

“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.

The UCCE environmental horticulture advisor has also served as director of UC Cooperative Extension in Orange County and interim director of the UC ANR South Coast Research and Extension Center.

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.

California Ag Today2016-05-31T19:28:11-07:00July 12th, 2015|

New Website Launched to Promote Yes Vote on Pierce’s Disease Referendum

Pierce’s Disease Website to Help Inform Winegrape Grower/Vintner Community

Winegrape growers and vintners anxious to better understand why their “yes” votes are needed for the upcoming Pierce’s Disease / glassy-winged sharpshooter (PD/GWSS) Referendum can now turn to a new comprehensive website: www.YESonPDref.org.

Designed and launched by a coalition of the California Association of Winegrape Growers (CAWG), Family Winemakers of California and Wine Institute, the new site provides in-depth analysis of the PD Referendum and the critical work the assessment has supported since 2001.

Up-to-date information on a variety of aspects concerning the PD Referendum can be found on the site, including voting procedures, facts about PD and GWSS, statistics on expenditures, the latest news and links to other sites with information on the PD/GWSS threat.

With passage of the last referendum in 2010, the PD/GWSS Board was given the authority to designate other pests and diseases detrimental to winegrapes for research funding. Since then the Board has designated the European grapevine moth (EGVM), red blotch (GRBaV), vine mealybug (VMB) and (BMSB) as serious threats to winegrapes.

“Through the industry supported Pierce’s Disease Control Program, we helped stop the spread of PD and soon commercial nurseries will have access to a variety of PD-resistant winegrapes–none of which would be possible without the PD assessment,” said CAWG President John Aguirre. “The program is operating at the lowest assessment rate since its inception; yet it continues to deliver tremendous value.”

Ballots for the vote on the PD Referendum will be sent out the week of March 30th. It’s important that every winegrape grower return his/her ballots no later than April 18th.

At least 40 percent of eligible growers must cast ballots to validate the referendum. Passage requires either: a “yes” vote by 65 percent of those voting who represent the majority of the assessment that was paid in 2014; or a “yes” vote by a majority of those voting who represent 65 percent or more of the assessment that was paid in 2014.

Patrick Cavanaugh2016-05-31T19:30:28-07:00March 3rd, 2015|