- Author: Jeannette E. Warnert
During his 15 years at Kearney, Jensen identified recent agricultural science graduates and hired them as staff research associates to work with him in the field and in his lab. He trained them on the most recent plant science research techniques, imparting skills for future careers as farm advisors.
UC Cooperative Extension advisors that worked with Jensen include George Leavitt, retired UCCE advisor in Madera County, viticulture; Harry Andris, retired UCCE advisor in Fresno County, tree crops; Bob Beede, UCCE advisor in Kings County, tree crops; Larry Bettiga, UCCE advisor in Monterey County, viticulture; Rhonda Smith, UCCE advisor in Sonoma County, viticulture; and Mary Bianchi, UCCE advisor in San Luis Obispo County, horticulture.
“Jensen was soft-spoken, had a good sense of humor and honest to a fault,” said Fred Swanson, the former director of Kearney. “He was an outstanding researcher, an accomplished photographer and has made a greater impact than anyone I’ve known by investing himself in other people.”
Jenson was raised on a farm in Weedpatch, Kern County. He earned a bachelor’s degree in soil science at UC Berkeley in 1942, then served for three years in the U.S. Army. He later earned a master’s degree in horticulture from UC Davis.
In 1947, Jensen was hired as an assistant farm advisor by UC Cooperative Extension in Tulare County at a salary of $3,600 per year. In 1972 he was promoted to viticulture specialist at Kearney.
As both a farm advisor and specialist, he worked to develop and obtain registration for commercial products to benefit the state’s grape growers, such as plant growth regulators and many other critical agricultural chemicals. Jensen’s detailed research on gibberellic acid applications helped identify optimal rates and timing that had eluded previous UC researchers. His work on bloom time applications have become an industry standard. Jensen also did the initial work on ethephon, a plant growth regulator used to enhance and improve fruit color. Jensen developed the use of ethephon to enhance raisin maturity, which almost eliminated the loss of raisin crops from early rains.
Jensen researched cultivar selection, vine spacing, trellising and integrated pest management. An early promoter of IPM practices, his contributions were instrumental in production of the UC Grape Pest Management Manual. He was the author or co-author of more than 250 publications and his scientific work is referenced in textbooks, journals and other viticulture publications. Jensen was a longtime editor of the scientific journal American Enology and Viticulture and was a world authority on table grape production.
Jensen retired from UC Cooperative Extension in 1987, but continued to conduct research and extension work for decades as an emeritus viticulture specialist and private viticulture consultant. In honor of his life-long body of work, Jensen received the Merit Award from the American Society for Enology and Viticulture in 2001. He was recognized for his contributions to California’s table grape industry at the 6th International Table Grape Symposium in 2010.
Jensen is survived by his wife of 27 years, Thelma Lile Essex, two daughters, three step-children and many grandchildren and great-grandchildren. A memorial service will be at 11 a.m. April 28 at Quail Park Retirement Village, 5420 W. Cypress Ave., Visalia, Calif.
- Author: Jeannette E. Warnert
A group of world IPM leaders presented UC Cooperative Extension integrated pest management advisor Walt Bentley with its Lifetime Achievement Award at the 7th International IPM Symposium March 27 in Memphis, Tenn. Bentley also received a Lifetime Achievement Award from the Association of Applied IPM Ecologists in February.
Professionals and academics in the field of integrated pest management convene the international symposium annually to bring together the scientists and people who practice IPM every day in agriculture, natural areas and community settings to collaborate and develop collective strategies. Some of the modern IPM challenges the group addresses are herbicide resistance, bed bugs and invasive species. For more than 20 years, these experts in pest management have selected champions in their field to receive awards of excellence.
Bentley began his UC career in 1977 as a UC IPM entomologist focusing on pest problems in almonds, grapes and stone fruit. Since that time, he has been committed to three major goals as part of the UC Statewide IPM Program:
- Coordinate with others
- Do research that meets the needs of farmers
- Develop relevant outreach
Bentley and a team of UC Cooperative Extension advisors and specialists and collaborating farmers developed IPM approaches and alternative control strategies that successfully reduce the use of the highest risk insecticides (carbamates and organophosphates) in California by 80 to 90 percent in almonds, table grapes and tree fruit. This reduction helps the environment and the producers.
- Author: Jeannette E. Warnert
An 80-panel solar array is being installed at the Kearney Agricultural Research and Extension Center to provide clean, green energy to the F. Gordon Mitchell Postharvest Laboratory, the sensory laboratory and a plant and sample handling lab. Initially, the array will generate 22.4 kilowatts of electricity per hour, a supply expected to cut the center's energy expenditures by $5,400 per year.
"We have a significant amount of electrically intensive equipment in the post harvest laboratory," said Robert Ray, superintendent of the physical plant at Kearney and coordinator of the project. "The laboratory includes a washer-waxer, fruit sizer, reach-in refrigeration boxes and sub-zero refrigeration units, among other equipment. The three facilities consume about 260,000 kilowatt hours of electricity per year."
Development of the solar farm is being supported by UC Agriculture and Natural Resources with a $100,000 allocation. Installation of the ground-mounted panels by JKB Energy of Turlock is expected to begin in early May.
"This is our first step toward developing renewable energy sources at the research and extension centers," said Luzanne Martin, a project manager for the nine-center system that stretches from Desert Research and Extension Center, near the border with Mexico, to the Intermountain Research and Extension Center, just south of Oregon. "We hope it will be a model project. When we see the savings we will try to look for renewable-energy options at our other centers and expand the array at Kearney."
Kearney facility and field staff are preparing a 140-by-25-foot area north of the post harvest laboratory and east of the sensory lab by leveling the land, pulling out alfalfa and installing underground conduits.
Ray said the solar farm will be expanded when funds become available to generate 78 kilowatts per hour, the maximum offset for the post harvest meter based on limits set by the Public Utilities Commission. In the future, solar arrays could also be built to provide the electrical needs of other Kearney facilities.
- Author: Jeannette E. Warnert
Nearly 2,000 third-graders visited the Fresno County fairgrounds March 23 to learn about the connection between the food they eat and their home county's No. 1 economic driver, agriculture.
Farm and Nutrition Day is sponsored by the Fresno County Farm Bureau and the Fresno Fair. UC Cooperative Extension in Fresno County has been involved since the event's inception in 2005; this was the first year for the UC Kearney Agricultural Research and Extension Center to bring an educational booth to the event.
KARE program and facility coordinator Laura Van Der Staay and her assistant Julie Sievert secured donations of lettuce seedlings, potting soil and pots to give to the children who visited the booth. In addition, Van Der Staay and Sievert used a felt board to teach the children about the benefits of eating right and exercise.
- Author: Jeannette E. Warnert
Research by Jim Stapleton, a UC Cooperative Extension advisor and Statewide Integrated Pest Management Program Coordinator for Natural Resources, based at the Kearney Agricultural Research and Extension Center, was published as Feasibility of solar tents for inactivating weedy plant propagative material in the March 2012 issue of the Journal of Pest Science.
Stapleton was inspired to conduct the study when a fire crew came upon a patch of Iberian starthistle growing along a stream in the Sierra foothills near Mariposa. Iberian starthistle is a robust, spiny weed native to the Middle East that, left unchecked, can dominate entire landscapes.
“Crews were going through and cutting dried plants and stacking them, but the seeds survived,” Stapleton said. “If you start moving plant material around with viable seeds, seeds are liable to spread, making the problem worse instead of better.”
Iberian starthistle is only one of many exotic, invasive plants that are capable of transforming California’s open areas into useless and unsightly tracts of land. On rangeland, for example, such weeds diminish desirable annual rangeland feed for cattle and wildlife. Weeds can shade out native wildflowers, make recreational areas inaccessible and, in dense infestations, become a fire laddering fuel.
In the past, such weeds may have been stacked and burned, but fire danger and air quality regulations have forced land managers to find alternatives.
“You wouldn’t want to try this on a 40-acre area,” Stapleton said. “Eradication of weeds with solar tents is best suited for small-scale weed infestations in warm climates.”
For the research project, Stapleton constructed three replicate solar tents with concrete rubble, mulberry shoots and clear plastic tarps. He placed johnsongrass rhizomes inside black trash bags along with about one cup of water. The sample bags were left inside the solar tents for 72 hours.
“Regardless of where you are, regardless of financial resources, you should be able to construct a solar tent,” Stapleton said. “Most of the materials needed – rocks and sticks – are easy to find on site.”
Air temperature inside the sample bags rose to 158 degrees Fahrenheit. Over the three days of the experiment, the rhizomes were exposed to temperatures 140 degrees and higher for 10 hours. None of the rhizome segments treated for three days in the solar tents sprouted. In contrast, rhizomes maintained in clear vegetable storage boxes and kept indoors for comparison all sprouted.
Annotated diagrams for suggested construction of solar tents can be found on the UC Solarization website.