Division of Agriculture and Natural Resources
Division of Agriculture and Natural Resources
Division of Agriculture and Natural Resources
University of California
Division of Agriculture and Natural Resources

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Tasty tree fruit in goods hands

Researchers from UC Davis and Washington State Univesity Extension are conducting research and workshops helping answer key questions for the tree fruit industry. Photo by Emily Kunz - WIFSS


In mid-September in California's Sacramento Valley the weather begins to tease us with the sense that fall is on its way. Interestingly, as the nights drop in temperature so too drops the desire for the fresh fruits we've enjoyed all summer. The melons, peaches, and plums have dwindled or disappeared from hometown fruit stands and our taste buds are being tickled by the site of the golden pears and the multiple varieties of apples newly arrived from local orchards.

Late in September our antennae go up at the sight of the colorful variety of sparkling fresh apples. During the summer months the abundance of fresh fruit might cause us not to reach for an apple, other than to pay attention to the old adage, “An apple a day keeps the doctor away.” The sight of the Washington sticker on the apple changes everything.

It's understood that it takes water to grow the fruit we consume. Something likely not appreciated is that researchers from the University of California and the Washington State tree fruit industry are working to understand the risk that water used to grow tree fruit may pose for human health. Water is a vehicle for bacteria that can cause foodborne illness.

Water quality training seminars for growers that have to comply with new water testing requirements have already begun in Washington with the leadership of UC Davis researchers such as Melissa Partyka, Ronald Bond, and Jennifer Chase and Ines Hanrahan of the Washington Tree Fruit Research Commission. Planning for others is underway in many other regions of the United States. These workshops are spreading the word about proper methods for obtaining accurate water samples in order to be in compliance with regulations in the Produce Safety Rules for the Food Safety Modernization Act (FSMA).

Partyka, a staff researcher and doctoral candidate in the Graduate Group in Ecology at UC Davis, Bond, a water quality researcher and the field research manager, and Chase, a doctoral student in the Graduate Group in Epidemiology, are all in the UC Agriculture and Natural Resources' Vet Med Extension and Water and Foodborne Zoonotic Disease Laboratory, headed by UC Cooperative Extension specialist Rob Atwill, which is within the Western Institute for Food Safety and Security. Dr. Hanrahan has become a valuable partner and liaison to the tree fruit industry, helping to both organize and staff the inaugural workshops while advocating for greater collaboration between UC Davis and Washington State University Extension.

The UC Davis team of Partyka, Bond, and Chase, have been in Washington State conducting research and workshops, which will help answer key questions for the tree fruit industry. For instance, whether growers can sample cooperatively and the impact of hold-times on testing accuracy. The trio are members of the Western Center for Food Safety, (WCFS), a Food and Drug Administration Center of Excellence, tasked to conduct research directly related to the FSMA food safety rule for agriculture water.

Bond, Chase and Partyka are featured in an article titled “Simple steps for water sampling” published in the July issue of Good Fruit Grower Magazine. The article, which helps demystify sampling for regulatory compliance, was based on interviews held during the agricultural water quality workshops conducted by these three in Washington last May.  The main article is accompanied by two additional guides: one titled “The math of food safety,” explaining the math required for agricultural water testing and “Water sampling 101,” a simple list of dos and don'ts for water sampling.

The rows of corn stalks have dried in the summer sun. The harvest moon will soon greet us in the evening sky. As our senses tingle with the oncoming change of season, the sound of the crunch of a juicy apple is music to our ears. Is it time to start melting the caramel?

Apple orchard in Yakima, WA, with mylar film for ripening. Photo by Ronald Bond - WIFSS
Posted on Friday, September 23, 2016 at 3:26 PM

Does sleep affect child obesity?

Suzanna Martinez will study how sleep duration affects the diet and physical activity of Mexican-American children.
September is Childhood Obesity Awareness Month and Hispanic Heritage Month kicked off on Sept. 15. A new Nutrition Policy Institute study on obesity among Mexican-American children ties in with both of these themes.

One in five Mexican-American children is obese, according to national statistics. While scientists agree that diet and exercise play a role in obesity, studies also suggest that children who don't get enough sleep may also be at increased risk for obesity. Does this mean that children who don't get enough sleep are more likely to become obese due to poor eating habits and being less physically active?

The National Institutes of Health has awarded $895,620 to Suzanna Martinez, Ph.D., assistant researcher for UC Nutrition Policy Institute (NPI) in the UC Division of Agriculture and Natural Resources, to try to answer that question. This will be the first pediatric study to examine health behaviors that link sleep to obesity in Mexican-American children.

Studies have shown that adults who are short on sleep may experience a change in metabolism and hormones, causing the person to eat more and to be more sedentary the following day.

To explore how sleep affects child obesity, Martinez will examine social and cultural factors that may impact Mexican-American children's sleep and, in turn, how sleep affects their diet and physical activity.

Inadequate sleep may affect a child's appetite.
Martinez hopes to provide guidance for which behaviors to target to prevent obesity.

“Some researchers just focus on diet, some researchers just focus on physical activity, while other researchers say it's all about the environment so we have to improve the environment in terms of food environment and opportunities to be active,” Martinez said. “There's very little research that tries to target all three aspects of health behavior – sleep, diet and physical activity – because there are so many factors to consider. We have to know which will make the biggest impact on obesity prevention. Is it sleep, diet or physical activity or a combination of all three?” Currently, programs are heavily focused on diet and/or physical activity.

Social and cultural factors may affect sleep

Martinez is essentially combining three different studies into one to evaluate the context of sleep and how it impacts obesity. The five-year study will occur in two phases.

She'll begin by looking at the culture, environment and socioeconomic status of the Mexican American families to see which factors may relate to sleep duration.

For example, Martinez said, “If less acculturated Mexican-American parents have stricter or earlier bedtimes for their children, is that protective for getting optimal sleep, less protective or does it even matter?”

Living in crowded housing or in neighborhoods with high crime, homelessness and drugs can impact sleep for urban Latino families, Martinez learned from interviews with Latino parents for a study she published in 2015

Sleep and physical activity and diet

The second phase of the study will involve evaluating the sleep duration of 40 Mexican American kids, ages 8 to 10, in the San Francisco Bay Area over two summers.

To record their sleep and physical activity, the participating kids will wear accelerometers during the day and while they sleep. The small, pedometer-like devices are worn on a belt around the hip.

For the first week of the three-week study, the children will be asked to get their normal sleep. During the second week, half of the children will be asked to sleep for less than 8 hours and the other half will be asked to sleep at least 10 hours. The third week, the two groups will switch over to the other sleep schedule.

Their diets will be measured using 24-hour dietary recalls. On Friday and Saturday, children will be asked what he or she ate the day before (Thursday and Friday). Starting with breakfast, the children will report what they ate and drank for meals and any snacks.

Martinez will evaluate whether healthy sleep or restricted sleep the previous night impacts the children's diet and physical activity the next day.

“With the crossover study, we will be able to see how kids compare when they get their usual sleep, healthy sleep or not  enough sleep  and how that impacts how much they eat and how much they move the next day,” she said.

Current child-obesity prevention programs are heavily focused on diet and physical activity.

No U.S. sleep guidelines

To maintain a healthy weight, U.S. Office of Disease Prevention and Health Promotion recommends that children get at least 30 minutes of physical activity daily and the Dietary Guidelines for America recommend that children eat a nutrient-dense and calorically balanced diet. The government office currently has no national sleep guidelines for Americans.

In a 2014 study, Martinez found that 82 percent of Mexican-American children ages 8 to 10 obtained less than the 10 to 11 hours of sleep the National Sleep Foundation recommended before 2015. Under the network of sleep researchers' new sleep recommendation of 9 to 11 hours for this age group, 20 percent of children received less than adequate sleep.

“There needs to be more research on sleep duration before we can say, ‘Sleeping this amount of time will help prevent obesity,'” Martinez said.

If her hunch is correct, promoting optimal sleep (at least 10 hours for school-age children) may be an effective way to reduce childhood obesity, and understanding the role of culture in obesity among Mexican-American children who have some of the highest rates obesity will be a key to designing effective solutions.

Research has shown that obesity contributes to numerous lifelong health problems, including heart disease, stroke, diabetes and high blood pressure. One in four overweight children become obese as an adult, and diseases like diabetes are presenting earlier than adulthood. National data show that 14 percent of white children are classified as obese, while 21 percent of Latino children are obese. With Latino children at increased risk, Martinez is committed to finding the causes of this disparity and to develop effective ways to reduce obesity among Mexican-American children.

This child obesity study is funded by a K01 Career Development Award from the National Institutes of Health National Heart, Lung and Blood Institute. Martinez has also been accepted into the K Scholars Program at UC San Francisco, which will provide her with peer support and mentorship to conduct the study.

Posted on Tuesday, September 20, 2016 at 11:56 AM

Twelve rules of thumb for creating a bee-friendly home landscape this fall

An example of pollinator-friendly plants at the Haagen-Dazs Honey Bee Haven Garden located at the UC Davis campus. (Photo : Evett Kilmartin ©UC Regents)
California's agriculture, plants and wildflowers depend on bees (and other pollinators) for pollination. Tiny, buzzing bees are not only fun to watch zoom around the garden, but they are crucial to our food supply and ecosystem.

“Fall, with its cooler temperatures, shorter days, and imminent rainfall, is the best time to plant a bee garden in California. Much of the plants' growth at this time will be in the roots rather than the vegetative growth, and that gives new plants an advantage when temperatures warm up and the soil dries in the spring. Fall and winter are usually the wet seasons in California, and a bee garden will benefit from the natural pattern of rainfall that helps plants get established,” according to California Bee-Friendly Garden Recipes (Pawelek et al. 2015)

With fall being the perfect time for planting consider making your home landscape bee-friendly and follow UC Agriculture and Natural Resources' California Bee-Friendly Garden Recipes - 12 rules of thumb for creating a bee-friendly home landscape:

  1. Learn the seasonality of plants and bees.
    Bees need both pollen and nectar resources from plants all year long. Sugary nectar provides energy for adult bees, and protein-rich pollen is used to feed their young. Plant not only a variety of plants (to ensure both pollen and nectar resources) but also make sure that they bloom at different times throughout the year, with the most active times of bees in garden running from February to October.

  2. Provide a diversity of floral hosts.
    A large variety of plants in a garden attracts a more diverse bee population. UC ANR researchers recommend planning a minimum of 20 different plant types to provide plenty of nectar and pollen sources for bees. If space or resources don't allow, consider plants that provide both nectar and pollen resources such as seaside daisy (Erigeron glaucus), blanketflower (Gaillardia x grandiflora), thyme (Thymus vulgaris), and coneflower (Echinacea purpurea).

  3. Give structure to the garden.
    When planning your garden arrange plants so it is easy to observe the bees that are visiting your landscape. Place taller plants or shrubs in the back and smaller or shorter plants in the front. Or you can plant in the shape of an island to allow viewing from all sides.

  4. Plant in the sun.
    Typically bees prefer flowers in the sunshine over the shade. Monitor the amount and location of sun in your home landscape and plant sun-loving bee-attractive plants in the sunniest section of your yard.

  5. Plant shrubs, perennials and annuals in patches.
    Most bees will visit one type or a few types of flowers each time they forage, an abundance of the same flower variety allows for more efficient foraging for bees. The California Bee-Friendly Garden Recipes publication recommends a 3.5 ft x 3.5 ft flower patch of the same variety.

  6. Don't forget to seed annuals.
    Plant seeds for spring blooming annuals and bulbs in the fall and take advantage of the winter rains and provide beautiful flowers in the spring. Great options include sunflowers (Helianthus annuus), Mexican sunflower (Tithonia diversifolia), California poppy (Eschscholzia californica), and zinnia (Zinnia elegans).

  7. Maintain flowers.
    Prolong a plant's blooming season by dead-heading. As soon as flowers begin to fade, wither and brown, pinch or cut-off the flower stem below the flower or right above the first set of healthy leaves. This allows the plant to continue to invest in producing more blooms and not seeds.

  8. Create a watering regimen.
    Regular watering of plants during blooming season allows plants to produce more flowers for a longer period of time. If a plant is water stressed it won't produce new flowers and nectar and pollen production declines. Consider plants that thrive in California's dry Mediterranean climate, UC Berkeley's Urban Bee Lab offers a list of the best bee plants with a large selection of California native options.

  9. Do not use pesticides!
    Applying pesticides to your home landscape can kill beneficial insects and bugs visiting your garden, including bees. Consider using integrated pest management practices that are natural or organic methods like hand-picking, spraying with water or natural insecticides. Contact your local UCCE Master Gardener Program to learn more about integrated pest management.

  10. Consider plant climate zones.
    Consider right plant, right place when selecting plants for your home landscape. Most gardening books, websites, plant labels and seed packets refer to a plants hardiness zone, climate zone or growing zone. Become familiar with the climate or microclimate in your area, the USDA Plant Hardiness Map and the Sunset Zone Map are a great starting guide for determining what plants will thrive in your garden space.

  11. Provide homes for nesting bees.
    A bee-friendly garden provides cover and a safe place for bees to raise young. Most bee habitats are either in the ground or in pre-existing cavities. Provide a nesting home for bees in your garden by leaving a small section of your landscape unmulched for ground-nesting bees. Nesting blocks, drilled holes in untreated wood or “bee-condos” can be offered to bees that prefer a pre-existing cavity habitat.

  12. Provide nesting materials, including a water source.
    Bees build their nests with mud, plant leaves and resins. Bees require a water source to not only drink but also to make mud for nest building. Fill a shallow water dish or birdbath to your garden, add small rocks or a floating cork for bees to rest and to prevent drowning.

Learn more with UC ANR and the UC Master Gardener Program

Create a bee-friendly garden with a variety of flowering plants, blooming seasons, nesting locations and a water reosource. Photo credit: Evett Kilmartin ©UC Regents
Learn about some of the 1,600 native bees in California at UC ANR's Native Bee Workshop, Saturday Sept. 17 at the Hopland Research and Extension Center. Attendees will learn from Dr. Gordon Frankie and Dr. Rollin Coville, UC Berkeley's Urban Bee Lab, how to identify bees and meet the needs of bees in the garden.

Interested in learning more about how to grow a buzzing bee-friendly garden? The UC Master Gardener Program has University trained volunteers who are eager to help. Volunteers are available to answer questions about preparing your soil, plant selection, pest management, and more. With local programs based in more than 50 counties across California and thousands of workshops a year there is sure to be an event or class near you. Visit our website to find your local UC Master Gardener Program, mg.ucanr.edu.  

Resources:

Pawelek, Jaime C., Frankie, Gordon W., Frey, Kate, Leon Guerrero, Sara, and Schindler, Mary. 2015. “California Bee Friendly Garden Recipes.” ANR Publication 8518, http://anrcatalog.ucanr.edu/pdf/8518.pdf

Ponder, Marissa, Frankie, Gordon W., Elkins, Rachel, Frey, Kate, Coville, Rollin, Schindler, Mary, Pawelek, Jaime, and Shaffer, Carolyn. 2013. “How to Attract and Maintain Pollinators in your Garden.” ANR Publication 8518, http://anrcatalog.ucanr.edu/pdf/8498.pdf

UC Berkeley Urban Bee Lab, www.helpabee.org

Pollinator partnership, www.pollinator.org

Posted on Friday, September 16, 2016 at 11:46 AM

UCCE advisor publishes third exciting children’s book

Nursing back to health a calf mauled by wolves in River of No Return, 11-year-old Jack learned essential skills that would serve him well as the third and final book of the Black Rock Desert Trilogy children's series unfolds. The novel opens with a touch of danger and distress, but ends with fast moving high adventure as it reaches its exciting conclusion.

River of No Return, written by UC Cooperative Extension advisor Rachael Freeman Long, chronicles the third summer at the family cabin for Jack, where he meets up with his animal pals from the previous books: Pinta the bat and Sonny the coyote. The trio were introduced in Gold Fever, and reunited in Valley of Fire. In River of No Return, Jack, Pinta and Sonny team up with other animal friends and foes – including Lux and Lacy the wolves and Midas the raven – to defeat and bring to justice the last of a band of poachers tormenting wildlife in the Black Rock Desert.

The loss of Sonny's loving parents, Lux's near fatal injuries, and the dark rage of Sarge, a greedy Air Force veteran who is willing to poach endangered species to become “the richest man in the world,” sets a somber stage. But Jack's commitment to his animal friends, his courage and ingenuity take the sting out of the story, even as he braves pitch dark tunnels, a raging underground river, and dreadful villains. Riveted as the novel unfolds, children may not realize that they are learning about wildlife and natural history.

All three books in the Black Rock Desert Trilogy are peppered with facts about animals, but Long gives bats, a focus of her agricultural research for UC Cooperative Extension, the spotlight. For example, readers learn that Pinta the pallid bat has big, pink ears that twitch constantly as they echolocate, when using sound waves to see in the dark. Later, Pinta tells Jack, “Remember, we migrate to the desert southwest during wintertime where it's warmer and there's plenty to eat.” Readers also learn that bats pollinate flowers, when Pinta turns yellow with pollen.

Long originally created the characters in the Black Rock Desert Trilogy to entertain her then two-year-old son during long commutes. He is now in college.

“The characters have been in my head for 20 years,” Long said. “It's sad to let them go.”

She may be hanging up the tale of Jack, Pinta and Sonny, but Long plans to keep writing children's books. Her new series, called Animal Adventures, will begin with A is for Alligator, in which two 8-year-old boys visit a city zoo.

“They wonder what it's like in the animals' natural habitat, and a portal takes them to the Everglades, where they learn everything they need to know about alligators,” Long said.

The series will continue, next is B is for Bear, for 26 volumes, one for each letter of the alphabet.

“I'm hoping to do something fun and teach kids about our natural world,” Long said. “There are a lot of books that are negative about school and authority. My series will focus on courage, resilience and goodness.”

All of Long's books are available on Amazon.com.

Posted on Thursday, September 15, 2016 at 9:20 AM

Biodigesters turn food into electricity, but can they also create fertilizer?

On a recent late-summer Wednesday, a freight container filled with cases of expired Muscle Milk protein drink awaited unloading at the UC Davis Renewable Energy Anaerobic Digester (READ) while a front-loader scooped heaps of spoiled vegetables into a mechanical processor. Nourished by a diet of assorted food waste from the UC Davis campus and area restaurants and markets, READ harnesses the activity of billions of microbes to produce biogas capable of generating 5.6 million kWh per year of clean electricity for UC Davis.

Out of date products are sent to the aenorobic biodigester to be converted to energy and now fertilizer

But a by-product of READ and other anaerobic digesters – the slurry of leftover solid and liquid material, or digestate – has caught the attention of UC Davis researchers interested in “closing the loop” on food production, consumption, and waste. When processed through an anaerobic digester, organic materials like food discards, expired or off-spec food products, or animal manure can be transformed into concentrated biofertilizers and soil amendments that are highly effective and easily applied to crops.

In an interdisciplinary collaboration at the Russell Ranch Sustainable Agriculture Facility, funded by the California State Water Resources Control Board and the California Department of Food and Agriculture, UC Davis faculty and students have developed a pilot-scale process for commercial production of several forms of this biofertilizer using digestate from READ and other nearby digesters. They are also evaluating their effects on yield and other agronomic metrics in corn and tomato field trials – paving the way for farmers and growers to take advantage of a highly sustainable source of plant nutrition.

The challenge and opportunity of fertilizer from anaerobic biodigesters

The digestate from READ and other digester facilities can be applied directly to soil as a fertilizer, but, because it has a limited shelf-life, it usually must be applied to land in the immediate region of the facility. With the input of food waste that can vary widely from day to day, a facility's digestate is inconsistent in texture and composition, making it difficult to transport and apply to fields using common farm fertilizer equipment.

Filtering and drying this digestate, however, results in solid and liquid forms that can be concentrated, homogenized, easily transported, and applied to soil through existing drip irrigation systems or surface spreading equipment.

This process could allow farmers and growers located further away, and working with common irrigation and fertilizer application equipment, to supplement or replace their synthetic fertilizer consumption with biofertilizers from food waste or animal manure.

How do biodigestate products measure up to synthetic fertilizers?

The research, co-led by professor Ruihong Zhang from the UC Davis Department of Biological and Agricultural Engineering (who also designed READ in partnership with Sacramento-based tech company CleanWorld) and Professor Kate Scow from the Department of Land, Air, and Water Resources, developed pilot-scale systems to efficiently and consistently separate the solid and liquid portions of food- and manure-based digestates. The researchers then examined the nutrient composition of the solid and liquid biofertilizer products, finding that biodigestate-based fertilizers contain valuable nutrients and microbes not found in many synthetic fertilizers.

In current field trials, the researchers are investigating the effects of each of the biofertilizer products on crop yield and quality. Their preliminary results show that it is possible to grow irrigated processing tomatoes and short-season corn using biofertilizer products as the sole source of fertilizer. The origin of the fertilizer matters, however – manure-based liquid fertilizer formed additional large particles after the final filtration, creating concerns about clogging the drip irrigation system. The team thinks an environmentally benign chemical sometimes added to manure digesters to clean the biogas may be the culprit of the problem, but future research is needed. The solid biofertilizer pellets they developed show much promise, as they can be applied using existing methods for spreading compost and can be economically transported farther away from the digester.

In addition to better understanding the best processes for producing and using the biofertilizers, further research is needed to understand how much of the nitrogen in each of the fertilizer products is available for uptake by the crop, as well as economic analyses to determine the commercial-scale production and transportation costs. The researchers will be able to narrow in on the agronomic and economic potential of biofertilizers through the upcoming analysis of the yield of the corn and tomato experiment plots at Russell Ranch. The results of a tomato experiment recently showed that the digestate fertilizers produced just as much fruit as a popular synthetic fertilizer.

UC Cooperative Extension advisor Gene Miyao looks at biofertilizer in its various stages, from raw waste to fertilizer

Interdisciplinary research for agricultural innovations

Russell Ranch, a program of the Agricultural Sustainability Institute, is designed as a shared space for interdisciplinary research and innovation. The biofertilizer research, among other active projects at Russell Ranch, is an example of the fulfillment of that intention. “The soil scientists are learning engineering, the engineers are learning biology, and the biologists are learning about soil,” Professor Zhang remarked.

The exchange also extends beyond the university: a recent UC Davis Biofertilizer Field Day drew attendees from the UC Division of Agriculture and Natural Resources, several public agencies, the agricultural sector, other universities, nonprofits, entrepreneurs, and food processors. If the research continues to illuminate a way forward for biofertilizers, these audiences may fill important roles in bringing this new technology into practice – and in recycling your lunch leftovers back into a more efficient and sustainable food system.

More information: UC Davis READ, Russell Ranch, and the biofertilizer research

The UC Davis Renewable Energy Anaerobic Digester was unveiled in 2014 as the nation's largest anaerobic biodigester on a college campus, and represented a unique private-public partnership. Professor Ruihong Zhang invented the anaerobic digestion technology used by CleanWorld, which developed it into one of the most advanced commercially-available digester systems in the country.

Russell Ranch Sustainable Agriculture Facility is a “living laboratory” for interdisciplinary field research and innovation. Its flagship project, the Century Experiment, measures the long-term impacts of energy, water, carbon, and nitrogen inputs on agricultural sustainability in the flagship Century Experiment.

The biofertilizer research collaboration includes Zhang Lab graduate students Tyler Barzee and Hossein Edalati, Scow Lab postdoctoral researcher Daoyuan Wang, and Russell Ranch manager Israel Herrera. Collaborating institutions include CleanWorld, California Bioenergy, New Hope Dairy (Galt, CA), Fiscalini Dairy (Modesto, CA), and Sacramento Municipal Utility District.

Posted on Thursday, September 15, 2016 at 8:30 AM

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