- Author: Pamela Kan-Rice
“When I started, there were about 22,000 acres, now there are more than 68,000 acres,” said Krueger, who retired July 1 as UCCE advisor in Glenn and Tehama counties and director for UCCE in Glenn County. Part of that expansion can be attributed to Krueger’s research showing how almonds and walnuts can be produced on marginal soils with high density plantings and drip irrigation.
“Bill Krueger is a great asset to our agricultural community,” said Erick Nielsen, who grows prunes and olives in Orland.
“We have enjoyed working with Bill for many years,” Nielsen said. “He has always been the kind of guy to just jump right in and help. We have appreciated his dedication to agricultural research and his knowledgeable guidance.”
Raised on a farm in Prosser, Wash., Krueger was introduced to farming by his parents, who grew Concord grapes and cherries. He earned his bachelor’s and master’s degrees in horticulture at Washington State University, then worked for a year as foreman at Mt. Adams Orchard Company in White Salmon, Wash., tending cherries, apples and pears.
In 1980, Krueger moved to California to become the UC Cooperative Extension advisor for tree crops in Glenn County.
“I’ve spent my entire career in Glenn County,” remarked Krueger, who specializes in production of almonds, walnuts, prunes and olives.
Seeking opportunities for growers to diversify their crops, Krueger and his fellow UC Cooperative Extension advisor John Edstrom planted a test plot of walnut trees at the Nickels Soil Laboratory in Arbuckle in 1986.
They set up a walnut orchard with 202 trees per acre, much closer than the 60 trees per acre of a traditional orchard. The two varieties that Krueger and Edstrom planted produce a large proportion of walnuts on lateral buds, which allows for hedgerow planting and mechanical pruning. Each year, a giant hedger with eight 38-inch saws buzzed down one side of the tree rows, cropping back branches and encouraging production. In alternate years, they pruned the opposite side of the trees. Rather than being flood irrigated as most walnut orchards, the Nickels orchard was watered and fertilized using drip irrigation.
Crop yields from the dense walnut tree plantings compensated for the marginal soils. The successful demonstration plot led to thousands of acres of walnuts being planted on similar soils.
In 1992, he added responsibility for olives in Tehama County, where the number of acres of olive trees has doubled from 4,000 acres to approximately 8,000 acres. Krueger is internationally respected for his research identifying the most effective method of chemically thinning olives to increase the size of the fruit. Chemical thinning of olives has become a common practice among Sacramento Valley table olive growers.
Over the years, he has collaborated on the development of integrated pest management practices for almonds, walnuts and prunes. In 2004, Krueger was a member of the team that California Department of Pesticide Regulation honored with its IPM innovator award for the Integrated Prune Farming Practices Program.
“Over the years he has assisted us with many different pruning trials in both our olive and prune orchards,” said Nielsen. “The last project he helped us work on was a trial for various degrees of hand pruning versus mechanical pruning in prunes. Bill has a great sense of the current market for the different crops and has always been a front-runner on moving forward with research and development projects.”
Krueger developed pruning strategies to enhance early production of prunes while developing tree structure capable of supporting heavy crop loads. He helped refine mechanical thinning to manage prune crop size, a technique developed earlier by UC researchers, and his efforts to extend this research to growers helped it become a common practice when needed.
His work, in collaboration with others, on reduced pruning of almonds has helped growers save money by reducing pruning costs.
In addition to advising growers, Krueger served a total of 13 years as director for UCCE in Glenn County, from 1996 to 2001, then resuming the helm from 2004 until his retirement.
Krueger has applied for emeritus status with UC so that he can finish up a few projects, but also looks forward to working on his own 10-acre olive orchard south of Orland during his retirement.
On Aug. 17, Krueger will be celebrating his career with friends and colleagues at Mills Orchards in Hamilton City. For details, contact Jody Samons at (530) 865-1155 or jesamons@ucdavis.edu.
- Author: Diane Nelson, (530) 752-1969, denelson@ucdavis.edu
“Mel has been a mentor and leader within the range science community his entire career,” said Ken Tate, UC Cooperative Extension specialist, who holds the Russell L. Rustici Endowed Chair in Rangeland Watershed Sciences. “Mel’s ability to see emerging issues on rangelands, and to position UC ahead of these issues, has allowed us to keep our research and extension at the forefront of rangeland management.”
When George arrived at UC Davis in 1978, he was responsible mainly for forage trials, helping ranchers keep their land productive. But George could see issues with grazing and water quality on the horizon and worked to head them off at the pass.
In the early 1990s, he spearheaded the UC Cooperative Extension Rangeland Watershed Program, which uses education and applied research to help ranchers and regulators mitigate the risk of pathogens in water runoff from rangeland. Some 80 percent of California’s water passes through or is stored on rangeland and the UC Cooperative Extension Rangeland Watershed Program has helped develop management practices that keep that water clean.
“The Rangeland Management Program has been a tremendous help in protecting open space, habitat for plants and wildlife and healthy watersheds that California rangelands provide,” says Tracy Schohr, director of the California Rangeland Conservation Coalition, a band of 100 diverse environmental, ranching and policymaking groups committed to protecting the state’s diminishing rangeland. “They educate land managers and provide the objective, accurate information we need.”
George’s research and extension has improved millions of acres of rangeland in the United States, Africa, Europe, China and beyond. In 1991, for example, George worked with Chinese researchers to develop a research site in the Tibetan Plateau of Szechwan Province, helping develop a winter feeding program for their yak herds that doubled the survival of yak calves. In 1994, George helped Albania develop grazing practices to protect new forest plantations to replace those destroyed during the transition from Communist to democratic rule.
The list goes on and on.
“Mel has a knack for taking a complicated process and making it navigable for ranchers and other land managers,” says Tate who, like George, has been based in the UC Davis Department of Plant Sciences. “He has greatly advanced both the art and science of rangeland management.”
George got into range management in a round-about way, a journey that passed through farming and animal science and was nearly cut short by a plane crash.
Farming is in George’s blood going back 15 generations, a fact he learned not too long ago when he became a genealogy buff. He was raised in the Butte County town of Gridley and was the first in his family to attend college, receiving his bachelor’s degree in animal science from California State University, Chico. During his senior year at Chico, a professor interested him in range management, which led him to Texas Tech where he received his master’s in range management in August 1969.
The Vietnam War was in progress and in October 1969, George was drafted into the U.S. Army. In November 1970, he boarded a plane bound for active duty that crashed during takeoff, killing 40 people aboard. George was severely burned.
“But I lived, and was released with a medical profile that prevented me from going to a war zone,” George says.
He was stationed at Fort Ord until the summer of 1971 when he and his wife, Gail, moved to Logan, Utah, where George earned his Ph.D. in range ecology at Utah State University. He worked nearly three years on the faculty at California Polytechnic State University, San Luis Obispo, before coming to UC Davis in 1978.
George has earned countless awards over the years, including the Outstanding Alumnus at Utah State University in 2000, the prestigious James H. Meyer Distinguished Achievement Award at UC Davis in 2007 and the College of Agriculture Distinguished Alumnus Award from Chico State University in 2008.
George will stay busy in retirement, still working on a slew of rangeland research projects under way in the UC Davis Department of Plant Sciences.
“It’s such a fascinating field because rangeland is the most complex agricultural system there is,” George says. “You have to be willing to think outside the box to manage so many moving parts, and I like that. There are so many issues on the horizon like carbon storage and protecting biodiversity.”
And even in retirement, George will do all he can to keep our rangelands healthy and sustainable for generations to come.
- Author: Jeannette E. Warnert
Aflatoxin can form on a wide variety of crops, from corn to cotton to tree nuts. Careful management practices help keep levels low, but still hundreds of thousands of pounds of pistachios are rejected each year due to the presence of aflatoxin.
UC Davis plant pathologist Themis Michailides and his team of researchers at Kearney discovered how to expose pistachio trees to the spores of a beneficial fungus that displaces the fungi that produce aflatoxin. Displacing aflatoxigenic fungi with a beneficial fungus has never before been done in tree crops.
“We’ve gotten great results,” Michailides said. “The reduction in aflatoxin contaminated nuts has been up to 45 percent. We anticipate higher reduction with application of the beneficial fungus for multiple years and on larger acreage.”
The new process was approved by the U.S. Environmental Protection Agency in February and the California Department of Pesticide Regulation in May, in time for 60,000 acres of the 2012 California pistachio crop to receive the innovative treatment.
“This is a big step,” Michailides said. “There will be a tremendous savings to pistachio growers by reducing rejections and the need for resorting nuts before going to market.”
Aflatoxin was discovered in the 1960s when a flock of turkeys in England died after eating contaminated feed. Aflatoxin is produced by certain strains of the fungus Aspergillus flavus, which is commonly found in soil and decaying vegetation. Aflatoxin is a resilient foe. Roasting nuts does not destroy the toxin. Other crops, such as corn and cottonseed used as animal feed, can be treated with ammonia to reduce aflatoxin, however ammonia treatment is not possible for human food, such as tree nut crops.
All shipments of pistachios are tested for aflatoxins, and are rejected in Europe if contamination exceeds 10 parts per billion and in the United States if shipments have more than 15 parts per billion.
The use of beneficial fungi to fight aflatoxin was first discovered and investigated by Peter Cotty, a USDA Agricultural Research Service plant pathologist located in the School of Plant Sciences at the University of Arizona. Cotty’s research focuses on reducing aflatoxin presence in corn and cottonseed. In collaboration with Cotty, Michailides and his colleague Mark Doster, staff research associate in the Michailides lab at Kearney, found that Aspergillus flavus 36 (AF36) can be introduced into an orchard by inoculating “dead” wheat seeds and then dispersing the seeds on the orchard floor. Dew and soil moisture spur the development of harmless spores that colonize pistachios and prevent colonization by toxigenic fungus strains.
The Kearney scientists are continuing their cooperation with USDA’s Cotty as they expand the research to almonds and figs.
“We’re conducting micro-plot experiments with the almond industry at Kearney,” Michailides. “We hope to get an experimental use permit soon to make the treatment available to almond growers.”
Michailides’ aflatoxin research was funded by USDA, the California Pistachio Research Board, the Almond Board of California and a UC Discovery Grant. The research was made possible by the involvement of cooperating pistachio growers who opened their orchards to scientists for conducting AF36 trials.
- Author: Pamela Kan-Rice
While earning a bachelor’s degree in home economics education from South Dakota State University, Johns took a summer job with South Dakota Cooperative Extension teaching at an Indian reservation.
“One of my assignments was to teach nutrition to families on the reservation,” Johns recalls. “That’s where I learned that delivering a scripted program is not always the most effective. The beauty of Cooperative Extension is having the flexibility to tailor educational programs to meet the needs of your clientele.”
Although the Brookings, S.D., native had participated in 4-H and her father was a Cooperative Extension economics specialist at South Dakota State University, Johns didn’t really know the community-based educational organization until she began working for UC Cooperative Extension in 1974 as an advisor for Plumas, Sierra, Lassen and Modoc counties. She coordinated the 4-H youth development and nutrition education programs for those four counties until 1983, when she became a UCCE advisor in El Dorado and Amador counties in the same role.
In 1985, Johns transferred to San Mateo and San Francisco counties to serve an urban population as the UCCE 4-H youth development and nutrition, family and consumer sciences advisor. One of her projects was starting a school garden in Pacifica. She recruited senior citizens to teach the children how to grow vegetables. The senior citizens’ requests for guidance led her to develop TWIGS, 30 gardening and nutrition lessons for “Teams With Intergenerational Support.” Published in 1997, Johns continues to receive requests for the TWIGS curriculum. More than 3,500 copies have been sold to schools, after school programs, parks and recreation and YMCA programs, senior centers, nutrition networks and food banks in 22 states. California’s Department of Education uses TWIGS as an example of gardening curricula addressing education standards.
While serving the Bay Area, Johns earned a master’s degree in public administration with an emphasis in human resources at Notre Dame de Namur University in Belmont. In 2005, Johns was promoted to director for UCCE in San Francisco and San Mateo counties and director of Elkus Ranch, an environmental education and conference center in Half Moon Bay that provides hands-on learning experiences for San Francisco Bay Area youth. In 2011, Johns was also named director of UCCE in Santa Clara County.
In addition to promoting nutrition education and agricultural literacy through gardening, Johns has studied teen pregnancy. An article that she coauthored, “Best Practices in Teen Pregnancy Prevention,” was one of the most visited online articles of the Journal of Extension in 2005.
A founding member of the San Mateo Food Alliance System and a member of the statewide School Garden Network, Johns and nonprofit partners Hidden Villa and Collective Roots recently received a three-year grant of $173,000 per year from Sequoia Healthcare District to improve children’s health through garden-based learning.
While there have been groups who advocate for school gardens and those who promote nutrition, they haven’t always worked together in the past, says Jennifer Gabet, nutrition manager for Sequoia Healthcare District. Through a unique collaboration and development of a model teaching garden, 1, 2, 3 Let’s Grow! will emphasize growing edible plants, providing the students with fresh produce to eat and demonstrating how to prepare the fruit and vegetables they grow.
“Marilyn has been able to bring the two groups together, to see the garden as a mechanism to improve the school food environment and nutrition education,” Gabet said. “They teach science, but it doesn’t always include nutrition – discussion of the benefits of the foods grown and how students and families can include them in their diets to support their health.”
“This grant is pretty exciting,” Johns said, explaining that it incorporates nutrition education into hands-on activities for children, which is a more effective teaching method. She oversees the UC Master Gardener volunteers and UCCE nutrition educators who will be training K-12 teachers, parents and other participants at up to 34 schools on how to enhance children’s learning while gardening.
In retirement, Johns, who has been granted emeritus status, looks forward to continuing to contribute to garden-based learning as well as spending time with family and traveling for pleasure.
- Contact: Kathy Keatley Garvey
A team of nine entomology, cancer and nutrition researchers, in work published in the June 25 edition of Proceedings of the National Academy of Sciences, found that this new class of drug molecules stabilized the natural molecules and "effectively blocked neuropathic pain" - or pain caused by nerve damage. The research, conducted on rodents, is expected to lead to an orally active drug candidate for human clinical trials.
"This discovery offers a promising new approach to controlling chronic pain in diabetics," said lead author and project scientist Bora Inceoglu of the Bruce Hammock lab based in the Department of Entomology. "We were initially looking at anti-inflammatory compounds which regulate a key branch of an inflammatory pathway. These compounds are highly selective and inhibit a key enzyme called soluble epoxide hydrolase. Inhibition of this enzyme successfully blocks pain sensations."
"Our data indicate that this drug candidate is more effective on neuropathic pain caused by diabetes than any of the prescription drugs now on the market," said Hammock, a distinguished professor of entomology who holds a joint appointment with the UC Davis Comprehensive Cancer Center.
The research is significant in that in the United States alone, diabetics total 25.8 million or 8.3 percent of the population, and millions more - estimated at 79 million - are pre-diabetic, according to the American Diabetes Association. The Centers for Disease Control and Prevention tallies the economic burden of diabetes at approximately $170 billion a year.
Professor Daniele Piomelli, director of drug discovery and development at UC Irvine and who holds the Louise Turner Arnold Chair in Neurosciences, said that the study holds promise. He was not involved with the UC Davis research.
"Current medicines do not control well chronic pain produced by damage to the nerves," said Piomelli, professor of anatomy, neurobiology, and biological chemistry. "The study by Hammock and collaborators identifies a new class of chemical compounds that could change this situation. These compounds act by boosting natural signals, produced by the body, which curb both inflammation and pain. Exploiting the body's own 'medicines' is a great approach to creating safer medicines."
Piomelli cautioned that the experiments "were conducted in animals and need therefore to be confirmed by clinical trials."
UC Davis School of Veterinary Medicine anesthesiologist and pain specialist Alonso Guedes, also not involved in the study, said that the research shows that "stabilization of a class of bioactive lipid greatly reduces pain derived from nerve lesions. This novel and emerging knowledge may help fulfill a critical medical need for millions of animals and people afflicted by such pain modalities."
For the study, the UC Davis researchers used the Type I diabetes-induced pain model.
"Although Type II diabetes, associated with obesity, hypertension and metabolic disorders, is more prevalent in humans, to study the analgesic effects we selected Type I diabetes since pain manifests in an accelerated manner," said co-researcher and pharmacology doctoral candidate Karen Wagner. "In Type II diabetes patients, the occurrence of pain is delayed by many years of pre-diabetic or diabetic state, whereas our model affords a very rapid onset of pain."
Team member Fawaz Haj of the Departments of Nutrition and Internal Medicine, a leading nutrition and diabetes expert and a collaborator with the Hammock lab on diabetes, said that, "Intriguingly, in this study, acute treatments with soluble epoxide hydrolase inhibitors did not significantly affect the diabetic status of the animals, such as blood glucose levels and responses to insulin, indicating a selective effect on pain sensation. Neuropathic pain is a major co-morbidity of diabetes and an important debilitating factor that reduces the quality of life and this study accomplished a first in showing analgesic effects of soluble epoxide hydrolase inhibitors."
The researchers worked on a physiological pathway that was largely unknown until recently. When the enzyme, soluble epoxide hydrolase, is inhibited, "what happens is that the biological effects of a group of lipid metabolites, that are degraded by this enzyme, accumulate to effective levels," Hammock said.
"It turns out that a major function of these lipid metabolites is to selectively block pain sensation while sparing other types of sensations," Hammock said.
Inceoglu described neuropathic pain as "a debilitating condition and very difficult to treat with available painkillers or analgesics. Most analgesics are ineffective while those that reduce neuropathic pain often come with a variety of side effects that negatively affect the quality of life."
Nerve damage may be the result of trauma and chemotherapy agents or even diabetes itself. In diabetes, high levels of blood glucose damage the fine endings of sensory neurons that normally transmit pain-related information, the scientists explained. The aberrant signaling from the damaged neurons is interpreted as extreme sensitivity to touch and sometimes insensitivity to heat. "Even an innocuous touch, such as buttoning a shirt or the collar rubbing against the neck, or the vibration of being in a bumpy car ride can result in extreme pain," Inceoglu said.
"Almost half of advanced diabetic patients suffer from this painful condition which worsens as diabetes progresses," Inceoglu said.
Nerve and vascular damage can lead to gangrene and amputation. In advanced stages, the nerve damage leads to life-threatening heart and kidney diseases.
Physicians face a dilemma in selecting the right painkillers for the right conditions and with the least possible side effects, the UC Davis researchers said. Over-the-counter non-steroidal anti-inflammatory drugs (NSAIDs), for example, are completely ineffective for neuropathic conditions, Hammock said. Narcotics, like opium, can be addictive; withdrawal is difficult.
"Therefore, there is a great need to discover new approaches in combating pain," Hammock said. "New medications will effectively increase the number of choices for patients and physicians in treating intractable pain. Our study shows that the novel approach is effective and may not lead to the known side effects of narcotics or anti-depressants."
"It is still too early for these new compounds to reach the stores as analgesic drugs, since FDA approval takes a decade with very thorough evaluations," Inceoglu said. "However, once the feasibility of this approach is demonstrated, hopefully a major hurdle in moving toward clinical application is overcome."
The research, funded by the National Institutes of Health, supports earlier studies at UC Davis and later at Medical College of Wisconsin that showed the natural epoxy-fatty acids are analgesic molecules.
"Although very effective in blocking pain, unlike narcotics, these molecules do not affect coordination skills of animals," Inceoglu said.
The research team included Bora Inceoglu, Karen Wagner, Jun Yang, Nils Schebb, Sung Hee Hwang and Christophe Morisseau, all of the Department of Entomology; Bruce Hammock, Department of Entomology and UC Davis Comprehensive Cancer Center; Ahmed Bettaieb of the Department of Nutrition; and Fawaz Haj of the Departments of Nutrition and Internal Medicine.
"This is an interdisciplinary effort among neurobiologists, diabetes specialists, organic chemics and analytical chemists," said Hammock. "We could not have done this without sophisticated mass spectrometry equipment."
"The emerging mass spectrometric technique allowed us to analyze the tiny amounts of natural bioactive compounds, contributing to this pain discovery," said Yang.
Hammock directs the campuswide Superfund Research Program, the National Institutes of Health Biotechnology Training Program and the NIEHS Combined Analytical Laboratory. He is a Fellow of the Entomological Society of America, a member of the prestigious National Academy of Sciences, and the recipient of the UC Davis Faculty Research Lecture Award in 2001 and the Distinguished Teaching Award for Graduate and Professional Teaching in 2008.
Hammock's initial research involved regulating the development of insect larvae.