“Palms are the iconic and signature trees of California, especially the southern part of the state,” said Donald R. Hodel, UC Cooperative Extension advisor for Los Angeles County.  Hodel, an internationally recognized expert on palms and environmental horticulture. has written two new books about caring for palm trees in landscapes: “Loulu: The Hawaiian Palm” and “Biology and Management of Landscape Palms.”

In “Loulu” (University of Hawaii Press, $48, 216 pages), Hodel shares his experience and extensive research on Hawaii’s only native palm species. Several of the Loulu species are grown as landscape features in coastal Southern California. He describes each of the 24 species in detail and handsomely illustrates the plants’ leaves, flower stalks, fruits and habitat with more than 250 color photographs.

With (Britton Fund, Inc. of the International Society of Arboriculture (Western Chapter), $35, 162 pages), Hodel examines palm biology and its implications for managing these plants in the landscape, including disorders, pruning, transplanting, and disease and pest management. Proceeds from the sale of this book are donated back to the Britton Fund to support tree research.

“This book provides arborists and others in the landscape and tree-care industries with the necessary background information on biology and specific practices to manage these unique plants successfully,” said Hodel.

Hodel has been a student of palms for more than 40 years and is considered to be an international authority in palm horticulture and taxonomy. His research focuses on selection, planting and management of woody plants in the landscape with a special emphasis on plant water use, trees and palms.

He was honored with the 2010 R.W. Harris Author’s Citation award from the International Society of Arboriculture. The award, one of the top three given every year by the professional society, recognizes authors of outstanding and sustained excellence in the publication of timely information in the field of arboriculture.

Hodel has authored or co-authored more than 75 peer-reviewed journal articles, more than 375 trade or popular publication articles and six books, including “Exceptional Trees of Los Angeles.”  He has delivered more than 300 presentations to industry groups, professional and honor societies, university and other governmental agencies, and consumers about various aspects of landscape plant selection and management. 

To order “Biology and Management of Landscape Palms,” please visit http://www.thebrittonfund.org/publications. “Loulu” can be ordered at http://www.uhpress.hawaii.edu.

For more information on landscape plant care from UC Cooperative Extension, please visit http://celosangeles.ucdavis.edu. As part of the University of California, Cooperative Extension was established in 1914 to connect local communities to their state’s land grant university. An office serving each county in California responds to the changing needs of its local people, extending research-based information about food, health, agriculture, horticulture and the environment. 

To stop the transmission of dengue, a mosquito-borne virus that threatens some 4 billion people worldwide, it's crucial to focus on people movement, not just on the traditional mosquito control-and-prevention methods, say medical entomologists from UC Davis in ground-breaking research published Dec. 31 in the Proceedings of the National Academy of Sciences (PNAS).

In a two-year, finely detailed study of dengue transmission, a 13-member team led by Thomas Scott, professor in the Department of Entomology at UC Davis, found that human movement – people going from house-to-house to visit their friends and relatives – is a key component to driving the virus transmission.

"This finding has important implications for dengue prevention, challenging the appropriateness of current approaches to vector control," said lead author Steven Stoddard, a medical entomologist in the Scott lab and part of the team that included scientists from the U.S. Naval Medical Research Unit; San Diego State University; University of Iowa; Tulane University, New Orleans; and Emory University, Atlanta, Ga.

Dengue is spread by an infected female Aedes aegypti mosquito, a day-biting, limited flight-range mosquito that prefers human blood to develop its eggs. Dengue is caused by four distinct, but closely related, viruses and the most severe form of disease is life-threatening dengue hemorrhagic fever or DHF.

Some 500,000 people with severe dengue are hospitalized each year, according to the World Health Organization (WHO), and about 2.5 percent of those affected die.

"Dengue takes an enormous toll on human health worldwide, with as many as 4 billion people at risk – half of the world's population – and 400 million new infections each year," said Scott, a UC Davis entomology professor and principal investigator of a National Institutes of Health-funded grant. "The results from our study are focusing attention to the role human social networks in virus invasion and epidemic spread. At our Peru study area, we found that infection risk is based on the places a person visits and transmission dynamics are driven by overlapping movements of people who recently visited the same places, like the homes of their family and friends."

The unprecedented research, titled "House-to-House Human Movement Drives Dengue Virus Transmission," sought to address the question of whether people's movements explained infection risk and patterns of virus spread," Stoddard said.

The scientists found that people movement not only defined individual infection risk and local patterns of incidence, but resulted in rapid spread of the virus and marked heterogeneity in transmission rates.

Dengue is difficult to control, the researchers said. "We have limited tools to prevent dengue," Stoddard said. "These largely involve reducing the mosquito population through the use of insecticides or by eliminating water holding containers that serve as larval habitat. Traditional approaches to mosquito control for dengue prevention focus on the area around the homes of detected dengue cases, essentially based on the observation that the mosquito, Aedes aegypti, does not move far."

"The question going into the study," Stoddard said, "was whether people's movement could explain a rather poor relationship between the abundance of mosquitoes in a house and the risk of new dengue infections. So we knocked on people's doors looking for anyone with a fever. If we found someone, we asked them where they had been recently and if they visited other houses, we went there. And in the houses visited by people sick with dengue we found a lot more people infected with the virus than in houses visited by people who did not have dengue."

"Interestingly, it didn't matter how far away the visited houses were. The mosquito that transmits dengue virus prefers to stay in small areas, say in less than a 100-meter radius, but the distance between houses was often much greater than this. So it only makes sense that humans are frequently spreading the virus around as they commute between their homes and the homes of their friends and family. Altogether the data demonstrate what we expected, that human movements are really key to the transmission of this mosquito-borne virus."

The scientists reported 54 contact-site cluster investigations over two transmission seasons. Of those cases, two-thirds were students under age 22, and "who, on average reported visiting 8.55 places over the prior two weeks" between 5 a.m. and 10 p.m.

"The most common type of place visited was residential, often houses of friends or family," the researchers reported. "Contact with other households likely to be infested with infected mosquitoes at the time of infection was the best indicator of risk."

The results, he said, are important and interesting for several reasons: 
1. We demonstrate empirically that human movement has a powerful influence on the transmission of a mosquito-borne disease. This is a rather novel idea because historically models of dengue transmission have focused on the mosquito moving, not humans. 
2. People's movements are influenced by social connections. Our data suggest that social networks are important in dengue just as they are in flu or HIV spread. This is an idea we want to explore further. 
3. Traditional approaches to dengue prevention are geographical – that is, when a case of dengue pops up, the traditional response is to draw a circle around their home (usually 100-400 meters) and focus insecticides there. Our data suggest that first, the circle probably should be smaller and, most importantly, that every case should have three or four circles associated with it – drawn around all the houses most recently visited.

"Scientists use models of disease dynamics to assist in decision making and the design of effective disease control and prevention strategies," Stoddard said. "The models we use are very sensitive to assumptions about how a pathogen spreads. Our data shine new light on how dengue virus spreads, which could lead to new model development and more effective strategies for disease prevention."

Iquitos, a city of 437,620 nestled in the heart of the Amazon rain forest of northeastern Peru, is considered one of the world's primary "open laboratories" to study the transmission of the virus.

Dengue, known as a tropical and subtropical disease, has now begun to appear along the southern border of the United States, including Texas. Florida has also reported cases of dengue.

Humans serve as both the main carriers and multipliers of the virus. Patients infected with the dengue virus can transmit the infection for 4 to 5 days or a maximum of 12 via Aedes mosquitoes after their first symptoms appear, according to WHO.

Scott said that "the next phase of our research is aimed at understanding how variation in human behavior influences transmission and applying that knowledge in enhanced disease prevention strategies."

Scott and Stoddard are affiliated with the Fogarty International Center, NIH, Bethesda, Md.

Other co-authors of the research paper:

• Amy Morrison of the Scott lab, UC Davis Department of Entomology, and U.S. Naval Medical Research Unit Six, Lima and Iquitos; 
• Brett Forshey of the U.S. Naval Medical Research Unit Six and Department of Biostatistics, College of Public Health, University of Iowa; 
• Valerie Paz-Soldan, Global Health Systems and Development, Tulane University School of Public Health and Tropical Medicine, New Orleans; 
• Helvio Astete, Stalin Vilcarromero, Eric Halsey and Tadeusz Kochel, U.S. Naval Medical Research Unit Six, Lima and Iquitos; 
• Robert Reiner of the Scott lab, UC Davis Department of Entomology and Fogarty International Center;
• John Elder, Graduate School of Public Health, San Diego State University; 
• Gonzalo Vasquez-Prokopec and Uriel Kitron, Department of Environmental Studies, Emory University, Atlanta, Ga., and Fogarty International Center

The dengue research was supported by Scott's grant from NIH, and funds from the U.S. Department of Defense Global Emerging Infections Systems Research Program, and the Military Infectious Disease Research Program.

New studies showing production costs for beef, alfalfa hay, corn silage, rice, prunes (dried plums), raspberries and avocados (conventional and organic) are now available from the University of California Cooperative Extension.

Each analysis is based upon hypothetical farm operations using practices common in the region. Input and reviews were provided by farm advisors, researchers, growers, farm accountants, pest control advisers, consultants and other agricultural associates.

Assumptions used to identify current costs for the individual crops, material inputs, cash and non-cash overhead are described.  A ranging analysis table shows profits over a range of prices and yields.  Other tables show the monthly cash costs, the costs and returns per acre, hourly equipment costs, and the whole farm annual equipment, investment, and business overhead costs.

The new studies are:

Sample Costs for Finishing Beef Cattle on Grass, 2012, Sacramento Valley, by Larry C. Forero, Roger S. Ingram, Glenn A. Nader, Karen M. Klonsky, and Richard L. De Moura.

Sample Costs to Produce Corn Silage, 2012, San Joaquin Valley by Carol A. Frate, Brian H. Marsh, Karen M. Klonsky, and Richard L. De Moura.

Sample Costs to Produce Rice, 2012, Sacramento Valley by Christopher A. Greer, Randall G. Mutters, Luis A. Espino, Paul Buttner, Karen M. Klonsky, Richard L. De Moura and Kabir P. Tumber.

Sample Costs to Establish a Prune Orchard and Produce Prunes, 2012, Sacramento Valley by Richard P. Buchner, Joseph H. Connell, Franz J. Niederholzer, Carolyn J. DeBuse, Karen M. Klonsky, and Richard L. De Moura.

Sample Costs to Produce Fresh Market Raspberries, 2012, Central Coast by Mark Bolda, Laura Tourte, Karen M. Klonsky, and Richard L. De Moura.

Avocado Sample Establishment and Production Costs and Profitability Analysis for Ventura, Santa Barbara and San Luis Obispo Counties, 2011, Conventional Production Practices and Avocado Sample Establishment and Production Costs and Profitability Analysis for San Diego and Riverside Counties, 2011. Conventional Production Practices by Etaferahu Takele, Gary Bender and Mao Vue.

Avocado Sample Establishment and Production Costs and Profitability Analysis for Ventura, Santa Barbara and San Luis Obispo Counties, 2011, Organic Production Practices and Avocado Sample Establishment and Production Costs and Profitability Analysis for San Diego and Riverside Counties, 2011, Organic Production Practices by Etaferahu Takele, Gary Bender and Mao Vue.

All cost of production studies are available online at http://coststudies.ucdavis.edu, at UC Cooperative Extension offices or by calling (530) 752-3589.  For additional information on the studies, contact Richard De Moura at rdemoura@ucdavis.edu in the UC Davis Department of Agricultural and Resource Economics.

As a boy growing up in Bakersfield, Kent Brittan was fascinated with bugs. His interest in bugs led to a career in crop research for the University of California Cooperative Extension. After nearly 34 years of advising Central Valley growers about cotton, vegetables and grains, Brittan retired on Nov. 1.

For the past 17 years, Brittan was a UC Cooperative Extension advisor for Yolo, Solano and Sacramento counties and director of UC Cooperative Extension in Yolo County.

“Kent has been a great resource in Yolo County,” said Richard Rominger, a long-time grower in Winters and deputy secretary of the U.S. Department of Agriculture during the Clinton Administration.

Over a number of years, Rominger and his sons have provided Brittan with plots of land for studying different varieties of wheat, barley, oats and triticale, a cross between wheat and rye. In addition to small grains, Brittan also had variety trials for corn, safflower, canola and sunflower seed production in other parts of Yolo County and in Solano and Sacramento counties to see how the different varieties grew in different soil and climate conditions, which were more disease resistant or showed desirable qualities for making flour, oil or seed.  He was instrumental in starting triticale grain production in Northern California.

“Kent has been a resource not only to us, but other farmers as well,” Rominger explained. “They could come by to see the comparisons of different varieties. He would hold field days and tell us what we needed to be planting in two to three years.”

Brittan studied insects at San Jose State University, where he earned a bachelor’s degree in biology in 1977. After graduation, Brittan began his career with UC Cooperative Extension as a staff research associate studying cotton at the USDA Cotton Research Station in Shafter. At a time when over a million acres of cotton were grown in California, he did research on pink bollworm, plant growth regulators and narrow row planting.

During his high school years, Brittan had had a summer job loading sacks of potatoes. Later, while doing research for UC Cooperative Extension on potato varieties grown in Eureka, Tule Lake, Half Moon Bay, Santa Maria and Kern County, he found himself hoisting 100-pound sacks of potatoes again.

“I used to know how many millions of pounds of potatoes I moved by hand,” Brittan said, chuckling. He explained that to evaluate the potatoes, more than 100 of the 100-pound bags had to be moved five or six times – from the field to the truck, from the truck to the shed, from the shed to grading tables, then back to the truck to put in cold storage and then out again to be cut for seed.

“We did this at two locations every year and had three other locations with 15 to 20 sacks,” he noted.

“A sack of potatoes is an ungainly thing to move because the contents move as you pick it up,” he observed. “The amazing thing is I still have a good back.”

“I worked with every color of potato you can imagine,” said Brittan, who shares a plant variety patent for a fresh white potato. With knowledge acquired from years of evaluating potato varieties, Brittan was part of a group of potato experts that advised McDonald’s on the best chipping variety to make into french fries. 

In 1995, he earned a master’s degree in vegetable crops at UC Davis, doing his thesis on the effects of salinity on processing tomato production. “My family thought that was really funny because I didn’t like to eat fresh tomatoes,” Brittan said. 

Brittan coordinated processing-tomato research, evaluating tomato varieties to select those that make the finest tomato paste. 

“There’s a reason why California is a world leader, producing more than one-third of the tomato paste in the world and UC Cooperative Extension is it,” Brittan said with pride.

As he reflected on his career, Brittan said, “With UC, I’ve had the ability to work with so many different people and have an impact on many different things.” 

Brittan authored or co-authored 16 peer-reviewed articles, 58 non-peer-reviewed articles and five cost-of- production studies. In addition, he’s studied garlic, onions, bell peppers, artichokes, asparagus and sweet potatoes, crops that aren’t commercially grown outside of California. When growers were losing over a million ears of corn to ear rot, he began screening the plant material and losses to the disease consequently dropped from 30 percent to less than 2 percent.

Yolo County grower Rominger lamented the loss of Brittan’s expertise.

“He was always available,” Rominger said. “If we had questions we could call him up. Those are the kind of people Cooperative Extension is losing to retirement. They provide a lot of information for farming.

“The extension service is really valuable. It’s one reason we have outstanding agriculture around California and the U.S. It’s something we don’t want to lose.”

Brittan has been granted emeritus status so he may continue small grains research, but is keeping his options open for retirement activities. Although agriculture has provided his living, Brittan said he may pursue his interests in photography and mass transit trains.