Posts Tagged: UC Davis

Honey: Nothing short of miraculous

“Honey, please pass the honey!”

That simple request, prefaced with a term of endearment for good measure, means there's honey on the table.

And well there should be. As the daughter, granddaughter and great-great granddaughter (and beyond) of beekeepers, I grew up with honey on the table. (And on my fingers, face and clothes.)

My favorite then was clover honey from the lush meadows and fields of our 300-acre farm in southwest Washington. My favorite now is Northern California yellow starthistle honey, derived from the blossoms of that highly invasive weed, Centaurea solstitialis, which farmers hate (and rightfully so) and beekeepers love.

“Almost every honey has its own unique flavor-- even when it is the same varietal,” says Amina Harris, director of the UC Davis Honey and Pollination Center. “There are characteristics we learn to look for, but even within that variety, the honey will differ from each area collected. For instance: avocado honey is known for being very dark amber with a flavor reminiscent of molasses, licorice or anise. However, once you start tasting a selection, some will taste like blackstrap molasses and very black licorice. Others will have almost a fruity flavor like dried figs or prunes. Most folks can't tell the difference – and then there are the honey nerds, like me!”

“My favorite all-around honey is one I keep returning to. I love sweet clover from the High Plains with its cinnamon hit —the spicy characteristic is just something I love,” Harris said. “My favorite ‘shock honey' is coriander. Collected near Yuba City, this seed crop gives us a honey that is like walking through a spice bazaar with hints of cardamom, cinnamon, allspice, nutmeg, coriander and — chocolate.”

The UC Davis Honey and Pollination Center, located in the Mondavi Institute for Wine and Food Science on Old Davis Road, periodically offers courses on the sensory evaluation of honey, as well as honey tastings. Next up: the center will host free honey tastings at its home base during the 105th Annual Campuswide Picnic Day on April 13, and at the California Honey Festival in downtown Woodland on May 4. Another popular honey tasting: California Extension apiculturist Elina Lastro Niño, based in the UC Davis Department of Entomology and Nematology, hosts a honey tasting at Briggs Hall during the annual Picnic Day.

There's more to honey than meets the eye — or the palate. The Honey and Pollination Center recently hosted a three-day Sensory Evaluation of Honey Certificate Course last October, using “sensory evaluation tools and methods to educate participants in the nuances of varietal honey,” Harris said. Northern California public radio station KQED spotlighted the course on its “Taste This” program.

And we owe it all to honey bees.

Pollination ecologist Stephen Buchmann of the University of Arizona (who received his doctorate in entomology from UC Davis, studying with native pollinator specialist Robbin Thorp), writes in his book, Honey Bees: Letters from the Hive, that each worker bee “may make four to ten or so flights from the nest each day, visiting hundreds or many thousands of flowers to collect nectar and pollen. During her lifetime, a worker bee may flown 35,000 to 55,000 miles collecting food for her and her nest mates. One pound of honey stored in the comb can represent 200,000 miles of combined bee flights and nectar from as many as five million flowers.”

Take a 16-ounce jar of honey at the supermarket. That represents “the efforts of tens of thousands of bees flying a total of 112,000 miles to forage nectar from about 4.5 million flowers,” writes Buchmann.

Of course, we primarily appreciate honey bees for their pollination services (one-third of the food we eat is pollinated by bees) but honey is more than just an after thought.

It's been described as “liquid gold,” “the nectar of the gods” and “the soul of a field of flowers.” Frankly, it's nothing short of miraculous.

And well it should be.

A honey bee sips honey from honeycomb. (Photo by Kathy Keatley Garvey)

A honey bee sips honey from honeycomb. (Photo by Kathy Keatley Garvey)

A honey bee sips nectar from a lavender blossom. (Photo by Kathy Keatley Garvey)

A honey bee sips nectar from a lavender blossom. (Photo by Kathy Keatley Garvey)

Trying leafy greens from a sweet potato plant

This time of year, it can be hard to resist the pull of sweet potatoes — roasted, mashed with butter, and topped with a combination of delectable treats from maple syrup to pecans to marshmallows. But did you know that the green leaves of the sweet potato plant also have the potential to be a tasty, nutritious food?

In Ethiopia, where sweet potatoes can be a staple crop, UC Davis graduate student Lauren Howe recently helped farmers taste test the leaves and consider this familiar crop in a new culinary light.

Watch a video to learn how to prepare sweet potato leaves:

The leaves of this drought-tolerant plant offer farming households there an alternative — and nutritious — food in the lean season, while they are waiting for its starchy, tuberous roots to be ready to eat. Introducing sweet potato leaves as a food option is intended to help farmers better diversify their families' diets, to include a wider variety of vegetables in addition to staple foods, especially during the dry season.

Lauren shared her experiences in Ethiopia on the Agrilinks website, where she recently won the Agrilinks Young Scholars blog contest with her writing and a short video from the field.

Lauren traveled to Ethiopia this summer to work with an organization called Send A Cow Ethiopia (SACE), on a Trellis Fund project. As part of the Horticulture Innovation Lab, each Trellis Fund project connects an organization in a developing country with a grad student from a U.S. university, to work together to benefit local farmers, while building the capacity of both the local organization and the student.

In Ethiopia, SACE helped Lauren better understand local contexts by connecting her with farming households to interview about their current farming practices and the role of sweet potatoes in their diets.

Later they traveled to meet with a group of about 25 farmers in the Ukara community to harvest leaves, cook together and discuss their perceptions of the leaves as a vegetable option.

Reflecting on taste tests, new foods, and rural communities

Background and related international agricultural research

Lauren's experience with a Trellis Fund project in Ethiopia was supported by the Horticulture Innovation Lab, a research program led by Elizabeth Mitcham of the UC Davis Department of Plant Sciences, with funding from the U.S. Agency for International Development. With a focus on fruit and vegetable innovation, the Horticulture Innovation Lab seeks to empower smallholder farmers in developing countries to earn more income and better nourish their communities — as part of the U.S. government's global Feed the Future initiative.

Past research from the Horticulture Innovation Lab has focused on other leafy greens, specifically African indigenous vegetables, and also on sweet potatoes themselves (orange-fleshed sweet potatoes, that is). Though the program has not done in-depth research on sweet potato leaves for human consumption beyond this small Trellis Fund project, you can find more information about eating sweet potato leaves and tips in this bulletin from the University of Arkansas Cooperative Extension, and a wealth of information about sweet potato farming and gardening from the University of California Vegetable Research and Information Center. 

Related Food Blog posts:

• New reason to give thanks for sweet potatoes
  How orange-fleshed sweet potatoes are making a difference in some African countries
• More African indigenous vegetables on more plates
  A brief look at some leafy greens popular in Eastern Africa
  
• Connecting with farmers over pineapple postharvest practices
  Another Trellis student experience with a video
  
• ‘Local' farm inspiration from half a world away
  A UC Cooperative Extension specialist reflects on his time as a Trellis student
  

 

Sweet potato leaves in Ethiopia - Horticulture Innovation Lab photo by Lauren Howe/UC Davis

close-up on sweetpotato leaves, stems and plant

A nutty idea: A little stress could be good for walnuts

When it comes to watering walnuts, most California growers believe you need to start early to keep trees healthy and productive throughout the long, hot summer. But according to striking results from a long-term experiment in a walnut orchard in Red Bluff, growers can improve crop production if they hold off irrigation until later in the season and directly measure their trees' water needs.

The findings from researchers at the University of California may help farmers optimize water use.

“It's a game-changer,” said walnut grower Hal Crain, who welcomed researchers on to his orchard to test irrigation optimization. “It's clear to me you can improve nut quality and yield by applying water based on what the tree wants and needs, rather than just watering when it's hot outside and the soil is dry. That's a big deal for walnut growers and for the entire agricultural industry.”

 Changing the paradigm

Crain is a second-generation farmer whose family has been growing walnuts in Butte and Tehama counties for 55 years. Like most walnut farmers, Crain had always started irrigating in early to mid-May when the days grew warmer and the trees sprouted leaves.

“That's standard practice for probably 90 percent of California's walnut growers,” said Crain, walking amid his trees on a sunny afternoon. “The theory is that when you irrigate early, you preserve the deep moisture in the soil that trees need to survive the heat of summer.”

But that's not how it works, the research shows. Instead, trees that grow in saturated soil early in the season don't develop the deep roots they need to thrive.

“With all the water right there at the surface, the lower roots suffer,” explained Bruce Lampinen, UC Cooperative Extension orchard management specialist with the UC Davis Department of Plant Sciences. “Trees end up with a very shallow root system, which doesn't serve them well as they try to extract moisture from the soil later on.”

Lampinen has long suspected that walnuts were getting too much water in the spring.

“A lot of the symptoms we see like yellowing leaves and various diseases can all be explained by overwatering,” said Lampinen.

So Lampinen did what scientists do: He set up an experiment. Five years ago, with funding from the California Walnut Board and the U.S. Department of Agriculture, he joined forces with Ken Shackel, a plant sciences professor with UC Davis, and Allan Fulton, an irrigation adviser with UC Cooperative Extension. Together, they led a team of scientists testing irrigation on Crain's ranch. 

“Hal is an exceptional partner,” Fulton said. “Farmers have a lot to accommodate when they host an experiment like this, with researchers going in and out of the orchard at all hours. He had to work around our people and the timing of our water treatments. He's always eager to experiment with technology and learn new things, and he shares what he learns with other growers. Hal completes the circle.”

Tough nut to crack

When is the best time to irrigate? Researchers say the trees hold the answer. Scientists use pressure chambers, which are air-pressure devices that measure a leaf or small shoot to gauge how hard the plant is working to pull moisture from the soil.

“Just because the soil looks dry doesn't mean the plant is suffering,” said Shackel, who specializes in plant physiology. “Pressure chambers let you ask the tree how it's feeling — sort of like taking a human's blood pressure — which is a much more accurate way to measure a plant's water needs.”

For the last five years, the team has been applying different water treatments to five blocks of trees. One block is getting standard, early irrigation. Crain's orchard managers begin irrigating the other blocks when the trees reach different levels of water stress based on pressure-chamber readings.

The trees that experience moderate stress are doing the best. Their irrigation usually starts in mid-to-late June, several weeks later than when standard watering begins.

“You can tell just by looking at that block that the trees are healthier,” said Crain, standing beneath a canopy of lush, green trees. “And, we're starting to see greater yields and better nut quality.”

Translating the research

The research is helping scientists advise farmers on irrigation.

“My biggest take-away is knowing when to start watering is a really important factor to the health of your trees,” Lampinen says.

Pressure chambers — sometimes called pressure bombs — can cost more than $3,000, and high-tech versions are under development.  

“I tell growers a pressure bomb would pay for itself even if you just used it once a year to determine when to start watering,” Lampinen said.

Crain is certainly convinced.

“When you irrigate based on your trees' needs, you optimize water,” Crain says. “I'm not using less water overall, but the water I do use is producing more food. That's good news for everyone.”

This story was originally published in the Fall 2018 issue of Outlook Magazine, the alumni magazine for the UC Davis College of Agricultural and Environmental Sciences. 

Change on the range

National Pollinator Week: Open house at UC Davis Bee Garden

June 18-24 is National Pollinator Week.

Do you know where your pollinators are? Think bees, birds, butterflies, bats and beetles.

And think flies. Especially syrphid flies, also known as "flower flies" and "hover flies."

The UC Davis Department of Entomology and Nematology is hosting an open house during National Pollinator Week from 11 a.m. to 2 p.m. at its bee garden, Häagen-Dazs Honey Bee Haven on Bee Biology Road, west of the central UC Davis campus.

Here's what you can expect to see or do:

• learn how to catch and observe bees up close
• see honey bees at work in an observation beehive
• learn about bee diversity and identification
• learn about what and how to plant for bees
• learn about growing and good pollination in home fruit gardens
• see easy-to-grow bee plants and solitary bee houses available for a donation to the garden.

The Häagen-Dazs Honey Bee Haven, installed in the fall of 2009 and located next to the Harry H. Laidlaw Jr. Honey Bee Research Facility on Bee Biology Road, off Hopkins Road, is a half-acre garden devoted to bee pollinator conservation and education. It was founded and sprang to life during the term of interim department chair, Professor Lynn Kimsey, director of the Bohart Museum of Entomology, who coordinated the entire project. Kimsey was singled out for her work when the Pacific Branch of the Entomological Society of America honored her and four others – "The Bee Team"– with the 2013 outstanding team award. 

A Sausalito team – landscape architects Donald Sibbett and Ann F. Baker, interpretative planner Jessica Brainard and exhibit designer Chika Kurotaki – won the design competition. The judges were Professor Kimsey; founding garden manager Missy Borel (now Missy Borel Gable), then of the California Center for Urban Horticulture; David Fujino, executive director, California Center for Urban Horticulture at UC Davis; Aaron Majors, construction department manager, Cagwin & Dorward Landscape Contractors, based in Novato; Diane McIntyre, senior public relations manager, Häagen-Dazs ice cream; Heath Schenker, professor of environmental design, UC Davis; Jacob Voit, sustainability manager and construction project manager, Cagwin and Dorward Landscape Contractors; and Kathy Keatley Garvey, communications specialist, UC Davis Department of Entomology and Nematology.

Others with a key role in the founding and "look" of the garden included the UC Davis Art/Science Fusion Program, founded and directed by the duo of entomologist/artist Diane Ullman, professor and former chair of the UC Davis Department of Entomology, and self-described "rock artist" Donna Billick of Davis. Miss Bee Haven, a six-foot long worker bee sculpture, the work of Billick, anchors the garden. The art in the garden is the work of their students, ranging from those in Entomology 1 class to community residents. Eagle Scout Derek Tully planned, organized and built a state-of-the-art fence around the garden.

Why are pollinators so crucial? Take it from the Xerces Society for Invertebrate Conservation:

"Pollinators are essential to our environment. The ecological service they provide is necessary for the reproduction of over 85 percent of the world's flowering plants, including more than two-thirds of the world's crop species. The United States alone grows more than 100 crops that either need or benefit from pollinators, and the economic value of these native pollinators is estimated at $3 billion per year in the U.S. Beyond agriculture, pollinators are keystone species in most terrestrial ecosystems. Fruits and seeds derived from insect pollination are a major part of the diet of approximately 25 percent of all birds, and of mammals ranging from red-backed voles to grizzly bears. In many places, the essential service of pollination is at risk from habitat loss, pesticide use, and introduced diseases."

So, on Saturday, June 23, you won't see any red-backed voles or grizzly bears. But you'll see bees, butterflies, birds and beetles.

And flies. Syprhid flies.

For more information on the open house, access https://hhbhgarden.ucdavis.edu/wp-content/uploads/2018/01/Pollinator-week-flyer-2018-1.pdf

 

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