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

UC Food Blog

Sustainable food systems depend on healthy plants

Discolored leaves. Decaying roots. Dead wood. Mother Nature offers a fascinating and colorful backdrop of clues to track microscopic killers. Much like any medical mystery, experts are called in to diagnose or identify a disease from its symptoms and recommend management strategies to prevent further damage or loss of healthy plants.

In the world of crop science mysteries, plant pathology solves the crime. The usual suspects include bacteria, fungi and viruses.

An example of fire blight bacterium on an apple.

Humans and animals depend on plants for their food supply and ultimately for their survival. When diseases threaten crops, a high-quality, affordable food supply is placed at risk. For growers, plant diseases can reduce crop yields. For consumers, reduced crop yields can drive higher food prices. Plant pathology research holds enormous implications for a sustainable food supply.

Florent Trouillas, who was named UC Cooperative Extension specialist in the Department of Plant Pathology at UC Davis and the Kearney Agricultural Research and Extension Center last year, explains the bottom line of most concern to growers.

"Once we identify a disease causal agent, a main question remains from growers. What growers really want to know is how to control the disease and prevent its spread to new healthy plants; they look to the University of California for solutions," Trouillas said.

A crisis in the food production system can impact other areas of society as well. In fact, history is filled with examples of how plant diseases influenced economies, environments and human societies.

Irish potato farmers faced starvation after a fungus attacked their crops.
Trouillas cites one of the most well-known examples in plant pathology: the Great Famine. Millions of Irish immigrants relocated to the United States in the mid-1800s after a terrible potato blight led to widespread starvation in Ireland. Experiments conducted in 1861 by Anton deBary, considered to be one of the founding fathers of plant pathology, proved the blight was caused by a fungus, which we now know is an oomycete. This plant disease had a direct impact on the Irish society with a subsequent Irish immigration wave into America.

Another historical illustration of plant pathology research occurred in the 1920s. The most common trees in the forests of the United States at the turn of the century were the majestic American chestnuts. The trees generated income for humans and the timber industry, served as a food source for people and animals, and provided habitat for wildlife. Then the trees started dying, until by the late 1920s, they had become the first tree in modern times on the brink of extinction. Plant pathologists were particularly adept at identifying plant diseases by this time and diagnosed the Cryphonectria parasitica fungus as the cause of the chestnut blight. By preventing the extinction of the pivotal species, plant pathology had a direct impact on the economy and the environment.

More recent major plant disease outbreaks in the United States involving plant pathology research have included Sudden Oak Death with devastating effects in California and Oregon forests, pitch canker killing California native pine species, and citrus canker in Florida, which has had a huge economic impact on the industry.

Veterinarians treat diseases in animals, physicians in humans. Trouillas describes the role of plant pathologists in similar terms. “We study the pathology of plant systems. Plant pathologists treat plants," he said.

Healthy plants ensure a sustainable food source and habitat for so many other organisms, including the human species.

Posted on Wednesday, January 28, 2015 at 9:25 AM
Tags: bacteria (5), disease (2), food (28), fungi (1), pathology (1), plant (1), potato (1), viruses (1)

Shaping Healthy Choices combines approaches to make a lasting impression on kids

Growing vegetables in a garden is part of a program to improve children's eating habits.
You can lead a child to fresh fruits and vegetables, but how do you entice them to eat healthful foods when you aren't watching?

“Simply offering healthy options is not enough to motivate children to make healthy choices,” said Sheri Zidenberg-Cherr, UC Cooperative Extension specialist in the Department of Nutrition at UC Davis.

“Moreover, imposing restrictions rather than providing children with options to make healthy choices can have long-term negative effects,” said Rachel Scherr, assistant project scientist, also in the UC Davis Department of Nutrition.

In 2012, more than one-third of children in the U.S. were overweight or obese, according to the Centers for Disease Control and Prevention. Studies have shown that obese children are more likely to be obese as adults, increasing their risk for health problems including heart disease, type 2 diabetes, stroke, cancer and osteoarthritis. To target the complex issue of eating habits, Zidenberg-Cherr and her UC Cooperative Extension and UC Davis colleagues designed a school-based program and tested it in Sacramento and Stanislaus counties through the leadership of UCCE nutrition, family and consumer science advisors Terri Spezzano and Yvonne Nicholson.

“Parents shared with me that their children are voicing input on meals and asking if they can add fruit to their salads,” a participating teacher told the researchers.

During the first year that the Shaping Healthy Choices Program was implemented in Sacramento County schools, the number of children classified as overweight or obese dropped from 56 percent to 38 percent. The participating students also improved their nutrition knowledge, ability to identify different kinds of vegetables and amounts of vegetables that they reported eating.

“I tried zucchini and yellow squash when I was little and didn't like it, but now I tried it and I love it!” said a 9-year-old student.

The Shaping Healthy Choices Program takes a multifaceted approach, combining nutrition education with family and community partnerships, regional agriculture, foods available on school campus and school wellness policies.

The garden-enhanced, inquiry-based nutrition curriculum was developed by Jessica Linnell, a doctoral candidate in the Graduate Group in Nutritional Biology; Carol Hillhouse, the School Garden Program director at the Agricultural Sustainability Institute;  and Martin Smith, a UCCE specialist in the Departments of Human Ecology and Population Health and Reproduction. The family and community partnerships featuring family newsletters were developed by Carolyn Sutter, a graduate student in the Graduate Group of Human Development, and Lenna Ontai, a UCCE specialist in the Department of Human Ecology. Lori Nguyen, a doctoral candidate in the Graduate Group in Nutritional Biology, Sheridan Miyamoto, postdoctoral scholar in the Betty Irene Moore School of Nursing, and Heather Young, dean of the Betty Irene Moore School of Nursing, organized community-sponsored health fairs.

School chefs are adding more fresh fruits and vegetables to their menus.
Gail Feenstra, deputy director and food systems analyst for the UC Agricultural Sustainability Institute, helped the schools set up systems to add fresh, locally grown produce to their menus. Jacqueline Bergman, a postdoctoral scholar in the Department of Nutrition, coordinated school-site specific wellness committees.

The UC Cooperative Extension and UC Davis team worked with classrooms to use Discovering Healthy Choices, a standards-based curriculum that incorporates interactive classroom nutrition, garden and physical activity education for upper elementary school students. Teachers partnered with UCCE to incorporate cooking demonstrations to show the connections between agriculture, food preparation and nutrition. To reinforce the lessons at home, Team Up for Families – monthly newsletters containing nutrition tips for the parents – were sent home with the students. School Nutrition Services purchased fruits and vegetables from regional growers and distributors to set up salad bars and prepare dishes made with fresh produce. The Shaping Healthy Choices Program activities were integrated into the school wellness initiatives.

“My students shared things they learned about safe food handling and safety in cooking,” said a teacher who participated in the study. “Parents said their children want to help in preparing meals at home.”

“My daughter is more interested in trying new foods and eating more fruits and vegetables,” reported one parent. “She often surprises the family by making a surprise salad snack for everyone.”

Preliminary analysis shows that nine months after the classroom education ended, the decrease in the students' body mass index percentiles, or BMI percentiles, was sustained. “This is a big deal,” said Zidenberg-Cherr, while cautiously encouraged by the program's success. “We are in the process of analyzing several aspects of the program — the data set is so complex and I have to feel 100 percent confident in our statements.”

Through a partnership with UC CalFresh, the researchers have expanded the comprehensive program to schools in Placer, Butte and San Luis Obispo counties. Determining feasibility for expansion of the program for broader dissemination is planned for the 2015-2016 school year. 

This project was funded by grants from the UC Division of Agriculture and Natural Resources and the U.S. Department of Agriculture.

The University of California Global Food Initiative aims to put the world on a path to sustainably and nutritiously feed itself. By building on existing efforts and creating new collaborations among UC's 10 campuses, affiliated national laboratories and the Division of Agriculture and Natural Resources, the initiative will develop and export solutions for food security, health and sustainability throughout California, the United States and the world.

Posted on Wednesday, January 28, 2015 at 8:38 AM

Southern Californians get another reason to love pizza

The newly planted pizza garden at the UC Desert Research and Extension Center in Holtville.
People love pizza, so they are sure to enjoy the new garden growing at the UC Desert Research and Extension Center in Holtville. A circle planted with wheat, tomatoes, bell peppers, herbs and spices, the garden looks like and produces the ingredients for pizza.

“Pizza can be a healthy meal, if you build it right,” said Stephanie Collins, outreach assistant at the Desert REC. “We can teach kids to add vegetables and educate them about whole grains and non-fat cheese.”

Collins initially envisioned the pizza garden teaching tool when she joined UC Cooperative Extension four years ago as a nutrition educator. The recent removal of a large tree stump made the location available.

The pizza garden will be part of the center's UC FARM SMART program, in which about 5,000 school children and “snowbird” winter residents annually visit the station to learn about UC's ongoing agricultural research in the desert area, tour the 255-acre facility on a hay wagon and taste products that are grown in the vicinity.

Green peppers growing in the pizza garden.
When they visit the pizza garden, they'll learn many of their favorite foods come from plants grown nearby in the productive agricultural region. The garden is divided into four wedges. The wheat, which is used to make the pizza crust, and alfalfa, which is an important feed for dairy cows, the source of cheese, is grown in one wedge.

“Alfalfa is cheese in the making,” Collins said.

Tomatoes, onions and arugula are planted in the next wedge. The tomatoes are used for traditional sauce and onions are a healthy and flavorful topping, but arugula?

“Arugula is great on pizza,” Collins said. “It has a strong, peppery flavor.”

In another section, visitors can smell, feel and taste the herbs that season pizza sauce. Oregano, basil, sage, thyme, chives, parsley and rosemary fill the third wedge.

The fourth section holds bell peppers and rhubarb.

Fresh herbs and spices fill one wedge of the pizza garden.
“The rhubarb is just for fun,” Collins said.

The garden is encircled with marigolds for the appearance of crust, and the wedges are dotted with a variety of non-pizza plants, like ornamental kale, vinca and lavender. These plants also serve an educational purpose, said Sam Urie, the UC FARM SMART manager at the Desert REC.

“A diversity of plants attracts beneficial insects, so they help the garden out,” Urie said.

The mostly senior citizen visitors pay $20 per person for the station tour, which includes a homemade lunch featuring locally produced foods. This year, the centerpiece of the meal will be carrot-ginger soup.

The visitors' fees help offset the cost of the tours for local children, who pay just $3 each.

For more information or to schedule a tour, contact Urie at (760) 791-0261, surie@ucanr.edu.

An initiative to enhance competitive and sustainable food systems is part of the UC Division of Agriculture and Natural Resources Strategic Vision 2025.

Posted on Wednesday, January 21, 2015 at 8:05 AM

Picture this: UCCE focuses on healthy meals for Healthy Weight Week (Jan. 18-24)

USDA MyPlate
Photos of sumptuous dishes are nearly as numerous as cat photos on social media. To sharpen people's focus on healthful eating, UC Cooperative Extension nutrition experts are using photos of food.

In 2011, the U.S. Department of Agriculture unveiled a new food graphic, MyPlate, to remind consumers to choose healthier foods. Work by Cooperative Extension in California that began years earlier influenced the adoption of MyPlate by USDA. Nutrition educators in California began using a plate graphic with USDA's My Pyramid several years ago in a research project with Expanded Food and Nutrition Education Program (EFNEP) and UC CalFresh Nutrition Education Program participants. While evaluating the use of their graphic, which was very similar to USDA's MyPlate, UC Cooperative Extension nutrition advisors found that a graphic depiction such as the one USDA is using for MyPlate is abstract for many families.

“We discovered that our clients need to see photos showing real food combinations in order to apply the MyPlate message to real food choices,” said Cathi Lamp, UC Cooperative Extension nutrition advisor. “They prefer to learn by viewing photographs with foods and meals they eat to see how it works and how they can implement the guide in their lives.”

A child places food on the MyPlate template.
In a project with more than 200 Latino consumers participating, the UCCE nutrition advisors learned which foods Latina, African American and other women would serve their families. Lamp and her colleagues developed materials with photographs of the preferred foods for nutrition education.

They evaluated the behavior of consumers who were trained with the revised Plan, Shop, Save and Cook curriculum with photos of food and compared it with the results of the original version of the lessons.

UCCE curriculum makes healthy eating easy.
“We found that the group receiving the revised Plan, Shop, Save and Cook and MyPlate materials reported the greatest change in the frequency of using MyPlate to make food choices, after considering differences among groups in initial behaviors and participant characteristics,” Lamp said.

UC CalFresh shows examples of healthy foods on plates.
Given the success of the photographs, UC Cooperative Extension created “My Healthy Plate” posters. Photographs of healthful food served on plates appear in all the EFNEP and UC CalFresh nutrition education materials, including the revised Plan, Shop, Save and Cook curriculum.

“Everybody enjoys looking at pictures of foods,” said Lamp. “So what we have now in our nutrition classes are lots of photographs of healthy examples.”

To listen to an interview with Cathi Lamp about My Healthy Plate in Spanish, visit Enseñando a comer ‘con sabor latino' con MiPlato at http://ucanr.edu/sites/Spanish/Noticias/radio/?uid=5983&ds=199.

For more than 100 years, the University of California Cooperative Extension researchers and educators have been drawing on local expertise to conduct agricultural, environmental, economic, youth development and nutrition research that helps California thrive. UC Cooperative Extension is part of the University of California's systemwide Division of Agriculture and Natural Resources. Learn more at ucanr.edu.

Posted on Wednesday, January 14, 2015 at 8:35 AM
Tags: Cathi Lamp (3), EFNEP (5), Nutrition Education (16), UC CalFresh (12)

Avocado production in the San Joaquin Valley gets closer

Planting avocados in research plots at the UC Lindcove Research and Extension Center.
The San Joaquin Valley is the heart of California agriculture, but hasn't been a hospitable home for commercial avocado production. UC Cooperative Extension specialist Mary Lu Arpaia is conducting research to change that.

Avocados are native of semi subtropical high elevation rainforests in Mexico and Central America. A delicious and highly nutritious fruit, the cultivation of avocado has spread around the world. In California, growers are having commercial success in areas with year-round mild climates, such as San Diego and Ventura counties.

Though avocados are frost sensitive to be sure, it is not the cold winter climate that is the greatest impediment to avocado production in the state's inland valleys. It's the heat.

“Plant leaves have stomata, small openings that allow water vapor to move out of the plant to cool the leaf surface,” Arpaia said. “It works something like perspiration on people. Moisture exits the pores and cools the skin.”

The stomata on the leaves of Hass avocados – the variety most favored by California consumers – close when the temperature rises above 90 degrees. No moisture is released from the closed stomata and the plant overheats, causing fruit drop.

“To grow avocados in the valley, we need to have a variety that can tolerate heat better than Hass,” Arpaia said.

An avocado variety currently named 465202-99 was planted in 2013 and already has a substantial crop for 2015. It looks nice and has performed well in taste panels.
Over the past four years, Arpaia has planted avocado varieties selected by UC Riverside at the UC Lindcove Research and Extension Center near Exeter. Twelve different varieties are now growing in the plot. The UC Riverside selections have undergone rigorous testing for yield, the length of time ripe fruit can remain on the tree, and eating quality.

“The ones that we're testing in the field have eating quality comparable to Hass,” Arpaia said.

Lindcove is situated where the valley floor is gently rising toward the Sierra Nevada. The slope allows cold air to slip down to lower elevations, giving farmers in the area an advantage of a few degrees in the winter. The geography has made the area an important location for citrus production. But heat-tolerant avocados could be an alternative.

East-side citrus farmers may be looking for other options if Huanglongbing (HLB) disease makes its way to the area. Already, the pest that spreads HLB, Asian citrus psyllid, is established in some parts of the valley and spreading. Once a tree is infected with HLB, it cannot be cured.

“Growers have made good money on avocados,” Arpaia said. “In the San Joaquin Valley, water is relatively cheap and we have better water quality than San Diego County. There are good, well-drained soils. Avocados' frost sensitivity is similar to lemons. If farmers have property where they can grow lemons, they could try avocados.”

An initiative to enhance competitive and sustainable food systems is part of the UC Division of Agriculture and Natural Resources Strategic Vision 2025.

Posted on Tuesday, January 13, 2015 at 8:18 AM
Tags: avocados (3), Mary Lu Arpaia (3)

Next 5 stories | Last story

Webmaster Email: jewarnert@ucanr.edu