- Author: Kathy Keatley Garvey, (530) 754-6894, kegarvey@ucdavis.edu
The agricultural pest, native to southeast Asia and now found in many parts of North America, was first observed in California in the fall of 2008 in the central valley, but was not identified until early 2009. It is reported to attack soft-skinned, ripening fruits, and has been a particular problem for raspberry and cherry growers in California. The research team – composed of Phaff Yeast Culture Collection curator Kyria Boundy-Mills of the UC Davis Department of Food Science and Technology; Frank Zalom UC Cooperative Extension specialist in the Department of Entomology at UC Davis and integrated pest management expert; doctoral student Kelly Hamby in the Zalom lab; and UC Davis visiting professor Alejandro Hernandez of University of Extremadura, Spain – published their work in a recent cover article of the journal Applied and Environmental Microbiology, the No. 1 cited journal in microbiology. "This represents the first look at potential yeast associations of Drosophila suzukii," said Hamby. “Often Drosophila have interactions with yeast communities, and communities often vary between host plant species, so it was a bit of a surprising that we found Hanseniaspora uvarum so often, though, we used only culture-based methods so other yeasts may be present that are hard to culture,” Hamby said. Hannah Burrack, a former Zalom lab graduate student (now an assistant professor and Cooperative Extension specialist in the Department of Entomology, North Carolina State University) originally found that olive flies were more attracted to yeasts that were isolated from the flies themselves than to the Torula yeast bait that is commercially available for olive fruit fly management, Hamby said. In their journal article, the authors wrote that “D. suzukii is unique in that it oviposits on marketable fruit relative to overripe or damaged fruit, and its injury facilitates colonization by other Drosophila species. If untreated, it is capable of causing a potential $860 million of revenue loss annually to blackberries, raspberries, and cherries in California, Oregon, and Washington. Knowledge of potential yeast associations could be used in lure development.” Zalom said the pest is a major problem in the area for backyard cherries. “Many residents have not been able to harvest cherries for several years now.”
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- Author: Robert Sanders, (510) 643-6998, rsanders@berkeley.edu
In a press announcement accompanying the release of the studies, Secretary of Natural Resources John Laird noted that “significant increases in wildfires, floods, severe storms, drought and heat waves are clear evidence that climate change is happening now. California is stepping up to lead the way in preparing for — and adapting to — this change. These reports use cutting-edge science to provide an analytical roadmap, pointing the way for taking concrete steps to protect our natural resources and all Californians.”
Laird and others appeared yesterday at a press conference in Sacramento, where Robert B. Weisenmiller, chair of the California Energy Commission, called the reports “historic” and praised the scientists who contributed.
“We scientists know that climate change is and will be significantly affecting the state’s energy supply and demand system,” he said. “The research in these assessments furthers our understanding of the impacts …. The challenges are enormous, but certainly this state has the capability to rise to those challenges, and with these types of studies we are going to be prepared. We will use these in the energy commission planning … to maintain a reliable grid, but also use this as a way of planning our research.”
Laird and Weisenmiller were joined at the press conference by Chief Ken Pimlott, director of the California Department of Forestry and Fire Protection (Cal Fire), who painted a grim picture of the state’s fire future. Of the 20 worst fires in California history, 11 have occurred since 2002, he said. The fire season in some areas has increased by an average of two months, and a few areas in Southern California now have a year-round fire season.
“Studies like those being released today are key in helping us move forward to prepare California” to deal with these large and damaging fires, said Pimlott.
State’s fire season longer, fires more intense
UC Berkeley fire expert Max Moritz, who contributed a paper about increased vulnerability to wildland fires in the state, has been warning of increasing fire danger for years.
“Our results reveal that California should prepare — regardless of the future we may face climatically — for quite different fire activity levels in the future,” said Moritz, UC Cooperative Extension specialist in the Department of Environmental Science, Policy and Management at UC Berkeley. “Though our models continue to improve, we still don’t know which future climate scenario will actually emerge. The challenge is to learn to ‘coexist’ with this natural hazard and move toward fire-resilient ecosystems and fire-resistant urban development.”
Speaking for the more than 120 scientists in 26 teams who contributed to the studies, Susanne Moser, a Social Science Research Fellow at Stanford University’s Woods Institute for the Environment, said that the report “spells out our new understanding of what climate change might mean to California. We are trying to inform the public, we are trying to inform the decision makers, with valuable information that they can use in … planning.”
The reports represent the third assessment commissioned by the California Climate Change Center since 2006, following up on discussions and topics presented at the Governor’s Conference on Extreme Climate Risks and California’s Future held last December in San Francisco. The new studies will provide a foundation for the 2012 Climate Adaptation Strategy, which is expected to be completed in December 2012.
David Ackerly, who co-authored three of the papers released yesterday, provided a new vegetation map that will allow planners to see how the Bay Area will likely change in the future.
“The big result that comes out of the models — and we have to remember that they are models — is a very wide expansion of chaparral and the loss of the cooler oak woodlands. And as climate change becomes more extreme, the Bay Area looks more and more like Santa Barbara or areas farther south, and the vegetation begins to look like Southern California, which is mostly scrublands,” said Ackerly, a professor of integrative biology. “That could take a hundred years or more, but the short-term result is that the dead trees become a fire danger and alien weeds invade.”
The short-term impacts are the most uncertain, he said, though UC Berkeley scientists hope to fill in these gaps through a broad research effort, the Berkeley Initiative in Global Change Biology.
“We hope to answer the question, ‘How fast can these changes really occur?’” he said.
Ackerly said that through his reports, which synthesized previous and ongoing research, he particularly wanted to link the expected decline of biodiversity throughout the state with a more visible impact on the ecosystem services people take for granted. The predicted march of desert northward into the San Joaquin Valley will make some areas unsuitable for agriculture, for example, while warmer winters may mean that plums and peaches will not get the winter chill they need to produce fruit.
“This is not merely nature for nature’s sake; nature and the services we expect from nature are all connected,” he said.
Gov. Jerry Brown is listening to these reports, according to Ken Alex, Brown’s senior policy advisor and director of the Office of Planning and Research, who also spoke at the press conference.
“Here in California, we do make policy decisions based on the science,” he said. “Gov. Brown actually reads the science, and he takes it very seriously, and I know that at a very deeply personal level, he wants to do something about climate change and wants to see California take the leadership role.”
The 26 teams submitting reports were led by researchers from around the state, including 15 from UC Berkeley, 19 from other UC campuses and two from Lawrence Berkeley National Laboratory. For highlights from the reports, link to the CEC’s press release (PDF). To download the full reports, link to CEC’s website.
“The incredible breadth of studies, as well as the depth of their analyses, reveals just how much the University of California has to offer in preparing us all to adapt to a changing climate,” Moritz added. “Hopefully, it also demonstrates how important it is to grow this scientific capacity within our public university system.”
The UC Davis research appears in a report, "Our Changing Climate," released today by the California Natural Resources Agency and the California Energy Commission. The report is the third assessment from the California Climate Change Center since 2006.
UC Davis scientists authored nine of the 35 studies contained in the report. The UC Davis work addresses climate change impacts on native fishes, agriculture, urban planning, water management and other issues:
* Peter Moyle, a wildlife, fish and conservation biology professor in the UC Davis Center for Watershed Sciences, studied the predicted effects of climate change on native fishes. His team found that most native fishes will suffer population declines, and some will likely go extinct. Fishes requiring cold water are particularly vulnerable.
Meanwhile, non-native fishes are expected to increase, although they will also experience habitat loss during severe droughts.
"California's unique native fishes are already in steep decline, and climate change is making the situation worse," Moyle said. "This is likely to increase the complexity of managing California's water supply. Preventing predictable extinctions is possible but will require planning now for increased water temperatures and more variable flows."
* James Thorne, a researcher in the Department of Environmental Science and Policy, helped create a model that simulates how rainfall interacts with the landscape. Thorne's research group looked at hydrologic data from the past and present to help predict what may happen in the future. That model was used for other studies in the report, such as those regarding fire and agriculture, allowing cross comparisons among the researchers' work.
Thorne also looked at six different policy options for urban growth, including smart-growth, infill and "business as usual" approaches.
"If we want the most lands preserved for a variety of different purposes -- agricultural and biodiversity protection, reduced fire threats -- the infill policy was best," Thorne said.
* Studies by Louise Jackson, UC Cooperative Extension specialist and professor in the Department of Land, Air and Water Resources at UC Davis, complemented Thorne's growth policy conclusion. Her group's case study focused on greenhouse gas emission mitigation and adaptation to climate change in Yolo County. They found that "channeling much or all future urban development into existing urban areas" will help preserve agricultural land and open space, reduce Yolo County's greenhouse gas emissions and enhance agricultural sustainability. Their research also found that farmers concerned about climate change were more likely to voluntarily adopt practices that would conserve water and reduce greenhouse gas emissions.
Jackson's group also developed an agricultural vulnerability index for California that identified four areas as especially vulnerable to the effects of climate change: the Sacramento-San Joaquin Delta; Salinas Valley; the corridor between Merced and Fresno; and the Imperial Valley.
* Jay Lund, director of the UC Davis Center for Watershed Sciences, examined climate change adaptations for managing water in the San Francisco Bay Area. His group's research suggests that Bay Area urban water demands can be largely met even under severe forms of climate change, but at a cost. The cost includes buying water from agricultural users, using more expensive alternatives such as water recycling and desalination, and some increased water scarcity. A shared connection of public water systems, or interties, recently completed for emergency response, greatly aids adaptation, the study reports.
* Joshua Viers, associate director of the Center for Watershed Sciences, co-authored a study analyzing "water year" classifications.
These indices determine whether a year is considered wet, dry or in-between, as well as how much water is allocated and who gets it.
"Unfortunately, the method to distinguish different water year types is indexed to historical climatic conditions and is intended to represent an equal chance for any given year," said Viers. "Our science suggests that future climatic conditions are not likely to represent this history, and thus water management agencies may need to reconsider these arbitrary indexing thresholds going forward to achieve a more equitable situation."
Viers also co-authored a study about climate change's impact on hydropower production in the Sierra Nevada. It found that an 11 F increase in air temperature would reduce hydropower in the area by about 10 percent, and that most reductions would occur in the northern Sierra Nevada. The central Sierra Nevada would adapt better to changes in runoff, while hydropower generation in the southern watershed would decrease.
Other institutions, including UC Berkeley, UC Santa Cruz, Stanford, the Scripps Institution of Oceanography, and Lawrence Berkeley National Laboratory researched climate change impacts on electricity consumption, sea level, wildfires and coastal flooding.
This assessment will provide a foundation for the state's 2012 Climate Adaptation Strategy, with completion expected in December 2012. Comprised of scientific studies from several academic institutions, the assessment is directed by the Governor's Office and intended to help state and local communities protect public health, grow the state's economy, ensure energy reliability and safeguard the environment.
- Author: Jeannette E. Warnert
To introduce more valley farmers to the benefits of conservation agriculture practices, Conservation Agriculture Systems Innovation (CASI) produced a six-part documentary featuring California farmers, UC researchers and agency representatives. The series premieres Aug. 6 on the CASI website (http://CASI.ucanr.edu) with a 7-minute segment that lays out the theoretical principles and the scientific basis for conservation agriculture. Additional segments will be released each Monday for five weeks thereafter.
Throughout the series, viewers will meet farmers who are implementing conservation agriculture successfully and profitably on their Central Valley farms. The 6- to 10-minute episodes review the core principles and practices associated with conservation agriculture systems and provide examples of successful local adoption.
After the six-week series airs, viewers, farmers and others interested in conservation agriculture are invited to the UC West Side Research and Extension Center in Fresno County for the annual Twilight Conservation Agriculture Field Day, Sept. 13. The event, which begins at 4 p.m. and concludes when darkness falls, is free and includes a barbecue dinner. Viewers can get clarification on points from the video series and meet many of the farmers and scientists featured in the documentary, plus get a first-hand look at conservation agriculture research currently underway. To register for the Twilight Field Day go to http://ucanr.edu/TwilightRegistration. The West Side Research and Extension Center is at 17353 W. Oakland Ave., Five Points.
“Our goal with the video series is to reach a wider audience of farmers with our research results and on-farm success stories, which show conservation agricultural practices can help make farmers more competitive and sustainable in the long run,” said Jeff Mitchell, UC Cooperative Extension specialist in the Department of Plant Sciences at UC Davis.
The Conservation Agriculture Systems Innovation documentary series includes the following episodes:
Aug. 6: “Introduction to conservation agriculture” – The first video defines conservation agriculture and outlines its increasing credibility in the global context.
Aug. 13: “Maintaining crop residues” – California farmers have tended to adopt “clean cultivation” systems, but research has shown that maintenance of residues from the previous crop or a winter cover crop helps improve soil and reduces evaporation from the surface.
Aug. 20: “Conservation agriculture in tomato production systems” – These systems cut production costs, reduce dust emissions and store more carbon in the soil.
Aug. 27: “Conservation agriculture in dairy silage production systems” – Three dairy farmers committed to conservation agriculture systems in their silage production share their secrets and success.
Sep. 3: “Minimum tillage systems” – This video features examples of a number of reduced pass or ‘pass combining’ tillage systems that have been developed during the past decade.
Sep. 10: “Coupling conservation tillage with overhead irrigation” – Overhead irrigation systems, such as center pivots, are particularly useful when coupled with conservation tillage.
For more information, contact Mitchell at (559) 303-9689, jpmitchell@ucdavis.edu.
- Author: Janet Byron
Conservation tillage seeks to reduce the number of times that tractors cross the field, in order to protect the soil from erosion and compaction, and save time, fuel and labor costs. Cotton crops are planted directly into stubble from the previous crop in the rotation.
In the study, conducted from 2000 to 2011 at the UC West Side Research and Extension Center in Five Points (southwest of Fresno), the number of tractor passes for a cotton-tomato rotation grown with a cover crop was reduced from 20 in the standard treatment to 13 with conservation tillage.
By the final years of the in the San Joaquin Valley study, cotton lint yields were statistically equivalent and even higher (in 2011) than with standard cultivation methods.
“The UC studies have consistently shown that conservation tillage can yield as well as standard tillage in a cotton-tomato rotation,” lead author Jeffrey P. Mitchell, UC Cooperative Extension specialist in the Department of Plant Sciences at UC Davis, and co-authors wrote in California Agriculture journal.
Their study, “Conservation tillage systems for cotton advance in the San Joaquin Valley,” as well as the entire July-September 2012 issue of California Agriculture journal, can be viewed and downloaded online at: http://californiaagriculture.ucanr.edu.
Mitchell is a founder of Conservation Agriculture Systems Innovation (CASI), a diverse group of more than 1,800 farmers, industry representatives, UC and other university faculty, and members of the Natural Resources Conservation Service and other public agencies (http://ucanr.edu/CASI). CASI defines conservation tillage as a suite of cultivation practices — including no-tillage, minimum tillage, ridge tillage and strip tillage — that reduce the volume of soil disturbed and preserve crop residues in the field. Conservation tillage is common in other regions of the United States and parts of the world and is beginning to gain acceptance in California agriculture.
Technological upgrades to tillage implements have been critical to the advancement of conservation tillage systems. These include equipment that can target operations to just the plant row rather than the whole field as well as accomplish several operations at the same time.
Fuel use was reduced by 12 gallons and labor by 2 hours per acre in the conservation tillage plots. This amounted to savings of about $70 per acre in 2011 dollars.
Mitchell noted that more research is needed on the adequate development of cotton stands and the prevention of soil compaction under different conditions, but that the benefits of conservation tillage are becoming increasingly obvious. “Provided that yield performance or more importantly bottom-line profitability can be maintained and the risks associated with adopting a new tillage system are deemed reasonable, conservation tillage systems may become increasingly attractive to producers and more common in San Joaquin Valley cotton-growing areas.”
Also in the July-September 2012 issue of California Agriculture:
Agricultural burning and air quality: Southern California farmers in Imperial County regularly burn crop residues of bermudagrass in the winter and wheat stubble in the summer. A study of ambient air quality adjacent to and downwind of agricultural burning sites in the desert county found that particulate matter levels (PM2.5) were 23% higher on burn days than on no-burn days at four locations. Researchers from the California Department of Public Health also assessed community educational needs regarding agricultural burning and developed fact sheets in English and Spanish targeting the general public, schools and farmers.
The value of privately owned oak woodlands: More than 80 percent of California’s 5 million oak woodland acres are privately owned. In a survey, researchers from Spain and UC Berkeley asked private owners of California oak woodlands to place a monetary value on amenities from their land such as recreation, scenic beauty or a rural lifestyle. The technique, called “contingent valuation,” found that landowners would be willing to pay $54 per acre annually for private amenities from their land and that their willingness to pay per acre decreased as their property size increased.
Microchips for woody plants: Radio-frequency identification (RFID) tags are widely used to track books in libraries, products during manufacturing, cattle from rangeland to the slaughterhouse, inventory in retail, runners in road races and much more. These tiny microchips (often the size of a grain of rice) are now being placed in woody plants such as grapevines and orchards to monitor crop diseases, track irrigation and pesticide applications, and help prevent the theft of valuable plants. In this review, Italian researchers discuss the emerging uses of RFID technology in agriculture.
Rainfall simulators to measure erosion: In their efforts to keep Lake Tahoe clear, researchers have been studying the movement of sediments into the lake using rainfall simulators. These fairly simple machines are placed on a slope; “rain” is created over a small frame, which allows sediment in the runoff to be collected and measured. However, the lack of standardization in erosion studies using rainfall simulators may be hampering progress. Mark Grismer, professor in the Department of Land, Air and Water Resources at UC Davis, makes the case for standardized field methodologies and data analysis.
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California Agriculture is the University of California’s peer-reviewed journal of research in agricultural, natural and human resources. For a free subscription, go to: http://californiaagriculture.ucanr.edu, or write to calag@ucanr.edu.
WRITERS/EDITORS: To request a hard copy of the journal, e-mail jlbyron@ucanr.edu.