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UC Food and Agriculture Blogs

Ground-Breaking Discovery Made in Preventing Devastating Citrus Disease

UC Davis chemical ecolologist Walter Leal. (Kathy Keatley Garvey)

In a ground-breaking discovery encompassing six years of research, an international team of scientists led by UC Davis chemical ecologist Walter Leal announced they've identified the sex pheromone of the Asian citrus psyllid (ACP), an insect that feeds...

Posted on Wednesday, December 13, 2017 at 1:20 PM

California’s nascent coffee industry to hold summit Jan. 18

Jay Ruskey, left, and Mark Gaskell, shown at a coffee tasting in 2015. They planted their first California coffee field trial in 2002.
Coffee is being commercially grown in California and coffee drinkers can't get enough of the locally produced beverage, which currently retails for about $18 per cup. Anyone who is interested in growing, processing or marketing specialty coffee in California is invited to a Coffee Summit on Jan. 18 at Cal Poly Pomona.

Until recently, American coffee was grown commercially only in Hawaii. To make the most of their precious water, California farmers have begun experimenting with coffee plantings and producing beans that fetch a premium.

“There are about 30,000 coffee trees now planted on about 30 farms and that acreage will continue to grow during 2018 with programmed new plantings,” said Mark Gaskell, UC Cooperative Extension advisor who works with coffee growers in Santa Barbara and San Luis Obispo counties. “Only a relatively small amount of the planted acreage is now producing, but the market interest and demand continue to outpace anticipated new production for the foreseeable future.” 

At the Coffee Summit, participants will learn about new opportunities for this high-value crop from industry professionals. Summit topics will include development of estate coffee, coffee production, pests and diseases, processing methods and marketing.

Coffee is planted from Morro Bay to San Diego, with production concentrated in Santa Barbara, Ventura and San Diego counties, according to Gaskell.

Coffee interplanted with established avocado orchards requires no additional land, water or fertilizer.

California coffee industry leaders from Santa Barbara and San Diego counties and agriculture professionals with University of California Cooperative Extension, University of Hawaii and U.S. Department of Agriculture will give presentations and answer questions.

Good Land Organics grower Jay Ruskey, who has been growing coffee in Santa Barbara County since 2002, and Gaskell will discuss growing coffee in California.

Based on their coffee variety research trials, UC Cooperative Extension advisors Ramiro Lobo and Gary Bender, both based in San Diego County, and Duncan McKee of Cal Poly Pomona will discuss which varieties are suitable for production in California.

“We are working collaboratively with UC Cooperative Extension to determine the best coffee varieties for our area,” said Valerie J. Mellano, Cal Poly Pomona professor and chair of the Plant Science Department. “Much of the California coffee is grown along the more coastal areas, but we are really interested in determining what will do well in the more inland areas, where it is a little hotter in the summer and a little colder in the winter.

“We are starting the second year of our trial and will be able to see how certain varieties hold up in the colder weather this winter, but we will not have any coffee yield data for a couple more years.”

Andy Mullins of Frinj Coffee, a cooperative of 24 farms including Good Land Organics, will discuss business and marketing opportunities for new California coffee growers.

The Inaugural Coffee Summit will be hosted by the Huntley College of Agriculture on Jan. 18, from 8 a.m. to 4 p.m., at the AgriScapes Conference Center at Cal Poly Pomona. Registration is $75 and includes a continental breakfast, lunch and coffee tasting. For more information and registration, visit http://bit.ly/2jtXyFP.


Related reading:

California Coffee http://www.slate.com/articles/news_and_politics/uc2/2015/03/california_coffee.html

Your coffee is from where? California https://www.nytimes.com/2017/05/26/business/your-coffee-is-from-where-california.html?_r=0

Farmer breaks ground with California-grown coffee success https://www.cbsnews.com/videos/18-cup-of-california-grown-coffee-sparks-industry-interest/

Posted on Tuesday, December 12, 2017 at 3:28 PM

Pine Tree Pests

Round swellings on pine terminals infected by western gall rust. (Arthur H. McCain)

This time of year, deciduous trees go dormant, and evergreen trees such as pine are more visible in the landscape. Pine trees, like other plants, can suffer from attack by pests, whether on your property or in our forested areas in California. Pine...

Posted on Monday, December 11, 2017 at 1:29 PM

Winter Weeds

Chickweed leaves and flower. (Jack Kelly Clark)

Weeds can be a real nuisance in gardens and landscapes, and even during the colder winter months, some kinds of weeds continue to grow and thrive. These are called winter annual weeds. Most weeds are classified as annuals, biennials, or perennials....

Posted on Monday, December 4, 2017 at 1:51 PM

Visit mountain mandarin orchards for tasty treats

Nestled in the rolling foothills of Placer County, just northeast of Sacramento, are more than 35 beautiful small family farms growing mandarin oranges. The warm days and cool nights in Penryn, Newcastle, Loomis, Lincoln and Auburn make this area a perfect place to grow sweet, juicy, seedless mandarins. Welsh settlers in the town of Penryn first planted Satusuma mandarin orchards in the 1880s; some of their descendants are still tending Satsuma groves today. These original growers have been joined by other families in providing tree- ripened, hand-picked fruit to Placer County and beyond.

Mandarins ripen from late November through January, just in time to find a favored spot in millions of Christmas stockings and Chinese New Year celebrations. The Mountain Mandarin Growers Association members welcome the public to visit the mandarin groves throughout the winter months when the fruit is at its peak, but during the first and third weekends in December visitors enjoy extra family-friendly activities as part of Mountain Mandarin Orchard Days.

Enjoy Mountain Mandarin Orchard Days

Orchard Days started eight or nine years ago, according to Mountain Mandarin Growers Association President Rich Colwell, owner of the Colwell Thundering Herd Mandarin Ranch in Penryn. Although growers' association members sell to stores and distributors and at farmers' markets, they decided to try to celebrate the harvest at the ranches, taking advantage of the example of the Apple Hill Growers Association in nearby El Dorado County. Colwell says, "If they like Apple Hill, we think they'll love coming up here to see what we have to offer." 

SideHillTo plan visits on Orchard Days, Dec. 2, 3, 16 and 17, visitors can visit the Mandarin Growers map page to find the groves and a list of activities at each ranch. First, enjoy the beautiful small family farms by taking a walk through the groves. Savor the fresh fruit itself, either by picking your own straight from the trees or by purchasing a bag of just-picked mandarins to take home or give to friends and family. Then sample some of the delightful products made from or infused with mandarins. Products created by the small-scale farmers include oils, sauces, honey, juice, cookies, cakes, fudge and spreads. Orchard Days activities include local wine and ale tasting, artists and crafters, visit with Santa, petting of goats and other farm animals and other winter fruits and vegetables. Visitors can see painted quilt squares on local barns as well as fabric quilts on display.

On Sunday Dec. 3, visitors may join the "Orange is the new Pink" 5K Walk for Breast Cancer, an un-timed walk along part of Penryn's Mandarin Trail, starting and ending at Mandarin Hill Orchards, 2334 Mandarin Hill Lane. To learn more and register, visit MandarinWalk.org.

HighlandNutrition and recipes

As well as being tasty, mandarins are nutritious. According to the California Department of Public Health's Network for a Healthy California, one average size Satsuma mandarin contains only 47 calories and 39 percent of the daily requirement for vitamin C. Also, in a 2008 USDA study, Placer County Owari Satusuma mandarins showed concentrations of the phytochemical synephrine that were up to six times higher than values previously determined for orange juice. The study concluded that 10 ounces of mandarin juice contains as much synephrine as one over-the-counter decongestant pill.

Spinach Salad with Mandarin Oranges

4 cups fresh spinach leaves
1 cup chopped center leaves of Romaine lettuce
1/4 cup sliced red onions
24 sections fresh mandarin segments

Toasted pecans or candied walnuts
Several thin slices of Mandarin orange
1 tblsp. feta or blue cheese
Drizzle with balsamic vinaigrette


Combine all ingredients in a large bowl and toss. Chill. Plate and top each serving with your choice of toppings (see suggestions).

Mandarin Orange Scones


1 3/4 cups all-purpose flour
2 tablespoons granulated sugar
1 1/4 teaspoons baking powder
1/4 teaspoon baking soda
1/2 teaspoon salt
6 tablespoons butter
1/2 cup buttermilk
Zest of 1 orange
11 ounces fresh mandarins, chopped

1 cup confectioners' sugar
1 teaspoon orange zest
3 drops orange flavoring
Fresh orange juice


SCONES: Preheat oven to 425 degrees F. By hand, mix flour, sugar, baking powder, baking soda and salt. Cut in butter. Add buttermilk, orange zest and Mandarin oranges. Turn dough onto well-floured board. Add flour as needed. Knead dough; make eight 1-inch round wedges. Score the eight wedges. Bake for 12 to 16 minutes.

GLAZE:Combine confectioners' sugar, orange zest, orange flavoring and enough fresh orange juice to make a runny glaze. Pour glaze over warm scones.

more recipes: (Mountain Mandarin Growers Association website)

Protect the Orchards!

NewcastleMandCindy Fake, UC Cooperative Extension advisor for Placer and Nevada counties, is working with the Mountain Mandarin Growers Association to keep the groves healthy as they face a serious threat.

Citrus from outside Placer County may carry the Asian citrus psyllid. This tiny insect carries the deadly bacterial disease called Huanglongbing (HLB) or citrus greening. HLB kills citrus trees and could destroy California citrus production and Mountain Mandarins. The insect is already in Southern California and efforts are being made to keep it out of Placer County.

Help protect the Mountain Mandarin industry by following these guidelines:

  1. Do not bring any citrus fruit, trees, or leaves into Placer County from other California counties, other states, or countries.
  2. Buy your mandarins from local Placer County growers.
  3. Buy only certified disease-free citrus trees from a reputable nursery. Do not share any uncertified citrus rootstock or budwood, as it could carry the disease.

Learn more about this threat to California citrus.

Learn more about visiting California farms and ranches at www.calagtour.org, the University of California Agritourism Directory and Calendar of events.

Posted on Wednesday, November 29, 2017 at 9:34 AM

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