- Author: Jeannette E. Warnert
After a successful tenure as an entomology professor and researcher at the University of Hawaii, Manoa, Marshall W. Johnson added a 10-year capstone to his career as UC Cooperative Extension specialist and research entomologist in the Department of Entomology at UC Riverside, based at the UC Kearney Agricultural Research and Extension Center. He retired at the end of June.
Johnson traces his interest in insects to a visit with a family friend on the outskirts of his hometown, Roanake, Va., when he was 10 years old. He was intrigued by a copy of “A Golden Guide to Familiar American Insects,” and the friend gave it to him. “That’s how I got started,” Johnson said. He never looked back.
Johnson earned bachelor’s and master’s degrees in entomology at North Carolina State University and in 1974 completed a Ph.D. in entomology at UC Riverside. After conducting short stints of entomological research at two locations on the mainland, he moved to Hawaii in 1983 to serve as a professor and focus his research on biological control.
In Hawaii watermelon production, Johnson was able to help farmers reduce pesticide use by 90 percent by showing that pesticide applications were killing natural enemies of a Liriomyza leafminer pest they were trying to control. He also worked on biological control of pests on cucumbers, tomatoes, green onions, pineapple, papaya and coffee.
In 1995, Johnson took a six-month sabbatical leave to UC Davis and realized how much he missed living on the mainland. He started looking for a new job and eventually was offered the combined extension and research position at his alma mater, UC Riverside, based at the off-campus research center in Parlier, Calif.
Johnson’s arrival coincided with the introduction of olive fruit fly in California, a serious pest that has devastated olive production in the Mediterranean region for more than 2,000 years. Olive fruit fly was detected in Los Angeles in 1998, and by 1999 had made its way into the San Joaquin Valley, the leading producer of the state’s olives.
To the great relief of valley olive growers, Johnson and his biological control colleague Kent Daane, UCCE specialist in the Department of Environmental Science, Policy and Management at UC Berkeley, found that hot summertime temperatures in the valley depress olive fly populations. But that didn’t provide a statewide solution.
Johnson and Daane worked together to introduce exotic natural enemies of the pest from Africa. The beneficial insects have been released from quarantine and introduced at several locations in California, with recovery of one species in the San Luis Obispo and Redwood City areas.
“We think it’s on the way to establishment. That’s a good sign,” Johnson said. “Now we're waiting to see if the parasite’s presence will have an impact on olive fly populations.”
Johnson was also involved in research that showed the Central Valley isn’t as hospitable to glassy-winged sharpshooters as other parts of the state. When it gets very cold, GWSS cannot move or feed. They either starve or get dehydrated.
“About every 2 out of 10 years, it gets cold enough in the valley that glassy-winged sharpshooter populations are reduced 90 to 95 percent,” Johnson said. “It is unlikely glassy-winged sharpshooters would ever become well established in the Sacramento Valley or the northern San Joaquin Valley. But it is well established in the Bakersfield area.”
Johnson ended his career with a video production project designed to raise awareness about integrated pest management. Posted on the website Extending Orchard IPM Knowledge in California, the videos include interviews with IPM practitioners, researchers and farmers plus overviews of specific pest control techniques, such as biological control, cultural practices and pheromones.
For his research and extension efforts, Johnson received numerous awards and honors over the years. Most recently, he was named “Distinguished Scientist of the Year,” by the International Organization for Biological Control. He is an elected fellow of both the Entomological Society of America and the American Association for the Advancement of Science. He was author or co-author of more than 200 peer-reviewed articles, book chapters, and extension publications.
During retirement, Johnson plans to spend more time pursuing the art of photography, mainly landscapes and seascapes, which he captures during travels around the United States. Johnson also plans to continue cataloging the history of the family of his mother, whose maiden name was “Marshall.” He has already traced his lineage back to a 1729 immigrant from Ireland. An earlier ancestor, a member of the provincial council in Pennsylvania, was governor for one day when William Penn was absent from the colony, Johnson said.
- Author: Jeannette E. Warnert
Larry Williams, professor in the Department of Viticulture and Enology at UC Davis, made use of a large, wine grape variety trial at Kearney to determine the contribution that water relations and vine hydraulics have on growth differences among grapevine cultivars. The study will help determine the most appropriate parameters for managing irrigation across divergent varieties and growing locations.
Following Williams' field demonstration, the presentations move indoors and include:
- Ecology of mycotoxin-producing aspergilli in raisin vineyards by Teresa L. O'Keeffe and Jeffrey D. Palumbo of USDA Agricultural Research Service
- Effects of pre-harvest calcium chloride and chlorine dioxide applications on fruit quality of crimson seedless table grapes by Matt Fidelibus, UCCE specialist in the Department of Viticulture and Enology at UC Davis,
- Wood disease management options for grapevines in the San Joaquin Valley by Philippe Rolshausen, UCCE specialist in the Department of Botany and Plant Sciences at UC Riverside
- Movento in table grapes: understanding use patterns and expectations by David Haviland, UCCE advisor in Kern County
- Understanding wine oxidation by Andrew Waterhouse, professor in the Department of Viticulture and Enology at UC Davis
Kearney-based Fidelibus hosts the event every two years at the field station, 9240 S. Riverbend Ave., Parlier. For the 2013 event he has applied for 1.5 hours continuing education credit.
Fidelibus will be tweeting about GrapeDay 2013 from his Twitter account @grapetweets using the hashtag #ucgrapeday. All Grape Day participants and attendees who use Twitter are encouraged to participate in discussions related to the event using the hashtag #ucgrapeday.
Attendance at UC Grape Day 2013 is free, but online advance registration is requested for planning purposes. To register, go to http://ucanr.edu/sites/grapeday.
- Author: Jeff Dahlberg
KARE's new solar energy project has been completed. PG&E did their final safety checks for the new 42 kW solar system located at our Postharvest Facility. This brings KARE's solar output to about 65 kW. Special thanks to JKB Energy, Bob Ray, Patrick West, Andy Padilla, Santiago Aldana, Rudy Gonzales, Dan Mulligan, and Dale Pattigan for all of their hard work in helping to get this done. KARE will continue to get more green technologies on the Center. We continually strive to lower our carbon footprint and look at new and innovative ways to bring green technologies to our farming operations.
- Author: Laura J. Van der Staay
The City of Parlier’s Earth Day celebration on March 30th attracted about 2000 attendees. Events included a tree planting, Easter egg hunt, family walk, folk dancing, zumba dancing, free raffles for prizes, games for youth, and face painting. Representatives from many local service organizations had booths that provided families with free items ranging from food to dental screening. KARE’s booth provided 1000 strawberry crowns and 2500 leaf lettuce transplants to the public. Youth from the local Leo club helped with handing out the plants and discussing the benefits of eating fruits and vegetables.
- Author: Laura J. Van der Staay
In 2003, the Polyphagous Shot Hole Borer (PSHB) was observed in Southern California. This beetle has a Fusarium sp. symbiont that causes susceptible host tree damage. The PSHB appears to be established in Los Angeles, Orange, and Riverside Counties. In the Los Angeles area, PSHB has attacked over 200 species of native, ornamental and horticultural trees, including the native Coast Live Oak, California sycamore, and about 57% of the commonly used street trees in the area. Avocado trees are susceptible; the beetle and fungus have been found in several backyard avocado trees as well as some commercial avocado orchards in Los Angeles and Orange counties. The PSHB has caused severe damage to commercial avocado orchards in Israel, and is a threat to California’s avocado crop which is worth about $460.6 million and accounts for about 87% of the US production.
To better understand the biology of and potential management strategies for the PSHB Fusarium complex threatening California’s avocado trees, Mary Lu Arpaia, Subtropical Horticulture Extension Specialist in the UC Riverside Botany and Plant Sciences Department and Kearney Agricultural Research and Extension Center, and David Obenland, Plant Physiologist, at USDA-ARS in Parlier, California, visited Israel in March, 2013. The PSHB is an invasive pest in Israel and was found in Israel’s commercial avocado orchards in 2009. The PSHB in Israel is causing serious damage, and Israeli research may help us develop detection and management strategies in California.
Biology and Behavior: A visit with Drs. Zvi Mendel and Stanley Freeman, Israel’s lead PSHB researchers provided insight into research on the biology and behavior of the PSHB Fusarium complex. Drs. Mendel and Freeman contend that even though the beetle uses several tree species as hosts, it is monophagous, only feeding on the Fusarium symbiont. According to their research, the beetle’s reproductive cycle in susceptible trees is: the adult pregnant female beetle bores through a tree’s bark, creates galleries under the bark, infests the galleries with a Fusarium fungal symbiont carried in the adult beetle’s mycangium (a specialized structure at the back of the jaw), and lays eggs in the galleries. Larvae are mostly female. While the larvae develop, the Fusarium sporulates. The developing larvae eat the fungus, develop into adults in about a month, and mate while in the gallery. The pregnant females exit the gallery through exit holes in the bark. To survive, the emerged pregnant female has about 48 hours to find a suitable host location and continue the life cycle.
Hygiene: The geographic area where the beetle is found in Israel appears to be expanding, even though the infested avocado trees in the primary infested area were destroyed. The PSHB is thought to have been transported in bins originating from the infested area. A best practice for California growers and packers will be to use clean bins and ensure that there is no vegetative matter in the bins prior to transport. This practice will also help reduce the spread of avocado thrips and persea mite.
Chemical control of the beetle or the fungus: There has been limited success in controlled lab situations, but field applications are not effective. So far, no effective chemical control technologies have been developed for the beetle.
Infestation: A mature orchard that was infested approximately 5 to 6 years ago became heavily infested within 2 to 3 years, and will be bulldozed. Infestations may require bulldozing orchards.
Detection: Mature avocado orchards with heavy infestation have severe limb dieback, many broken branches littering the orchard floor, dropped mature fruit, abnormally small mature fruit, and sugar exudates caused by the bore holes. A 2-year-old infested orchard did not exhibit very much limb dieback; when infestation of young trees is observed, it is usually on the base of the trunk (found in either the rootstock or the scion wood).
Spread to native and landscape hosts: Israel has seen the spread of the beetle to native oaks and the box elder. California will need to educate the public to help safeguard our native and landscape trees from the spread of the PSHB and Fusarium complex. Native and landscape tree infestations may make it difficult to control the spread of infestations into commercial avocado orchards.
California outlook: California must be diligent in looking for tree infestation. The avocado industry is working with the landscape industry and forestry service in California to understand the rate of infestation and range of susceptible hosts. Funding for surveys; understanding the beetle and fungal biology; developing control strategies, technologies and practices; and basic work on the origin of the beetle is essential. California researchers should collaborate with and learn from their Israeli colleagues.