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

Posts Tagged: almonds

Mandarin drought tips featured in final video of drought series

Because periodic droughts will always be a part of life in California, the UC California Institute for Water Resources (CIWR) produced a series of videos to maintain drought awareness and planning, even in years when water is more abundant.

The final video of the three-part series, which focuses on drought strategies for citrus, was launched April 6 on the UCTV Sustainable California channel. The first episode, which centered on alfalfa production, premiered Feb. 2 on the UCTV Sustainable California channel. The second video, on almonds, was launched March 2 on Sustainable California. A trailer with clips from all three episodes is here.  

The videos are inspired by a collection of 19 drought tips produced by CIWR in collaboration with UC Agriculture and Natural Resources researchers during the drought of 2010-16. The tips cover a broad spectrum of California crops, from alfalfa to walnuts. Topics also include salt management, use of graywater in urban landscapes, and the use of shallow groundwater for crop production. 

The drought tips collection and the drought tip videos were sponsored by the California Department of Water Resources. Following are links to each of the videos:

Drought strategies for alfalfa

The CIWR drought tip series opens with Cannon Michael of Bowles Farming in Los Banos. The alfalfa grower works with UCCE specialist Dan Putnam. “There's a lot of misunderstanding about alfalfa as a crop,” Michael said. “It does take water to grow it, as with anything, but you get multiple harvests of it every year.”

Drought management for California almonds

The second episode features almond producer Raj of Meena farms. He works with David Doll, UCCE advisor in Merced County. “One positive of this drought,” Meena said, “is that it has forced us all to be more efficient in how we use our water.”

Irrigating citrus with limited water

The series finale features Lisa Brenneis of Churchill-Brenneis Orchard in the Ojai Valley of Ventura County. She worked with UCCE advisor Ben Faber to install a new water-efficient irrigation system. “Irrigation is the only job we really have to do,” Brenneis said, “and we have to get it as right as we can.”

UCCE advisor Ben Faber is featured in the CIWR video on drought strategies in California mandarin production.

For a complete list of drought tips, see http://ucanr.edu/drought-tips.

Posted on Friday, April 6, 2018 at 7:33 AM
Tags: alfalfa (1), almonds (45), Dan Putnum (1), David Doll (8)
Focus Area Tags: Agriculture

Roof rats unnerve farm workers, damage orchard crops

Roof rats are causing damage in nut and tree fruit orchards.

Monitor for rodent activity and use bait stations before the growing season to prevent problems, UC ANR scientists recommend.

Roof rats are running rampant in California orchards this year, according to UC Agriculture and Natural Resources scientists.

“In pistachio and other nut orchards, roof rats are burrowing and nesting in the ground where they're chewing on irrigation lines, causing extensive damage,” said Rachael Long, UC Cooperative Extension advisor. “They are also nesting in citrus trees, feeding on the fruit and terrifying field workers when they jump out as people are picking fruit. The chewing pests are also girdling citrus limbs, causing branch dieback.” 

Rats like to eat fresh avocados.
The wet winter of 2017 led to lots of weed seeds for rats to eat. “Last season, rats were also nibbling on pomegranates, avocados, and other fruit and nut crops, rendering them unmarketable,” Long said.

Holes in the ground around the base of pistachio trees throughout a Yolo County orchard puzzled the grower.

“We looked for ground squirrels, but never saw any,” Long said. “We set up game cameras, but only got birds and rabbits. We put rodent bait in the holes, but the digging didn't stop.”

Long, the pest detective, cracked the case by consulting Niamh Quinn, UC Cooperative Extension human-wildlife interactions advisor based in Irvine. “She informed us that the damage we were seeing was from roof rats.”

Burrowing roof rats sounds like an oxymoron. While roof rats generally don't burrow in urban environments, their country cousins have been known to burrow.

“It's not true that they don't burrow,” Quinn said. “When I worked as staff research associate for Roger Baldwin, UC Cooperative Extension wildlife specialist, that is mostly what we studied, burrowing roof rats in orchards.”

Roof rats are nocturnal animals that climb in trees and burrow underground.

Control measures

Baldwin said, “It seems to be a good year for rats in a number of different areas and crops throughout the state. I've received more questions and comments about rats this year than perhaps the last 10 years combined. As for bait application, putting bait down burrow systems for rats doesn't usually work too well, so I'm not surprised that approach didn't work. Growers will likely have better luck with bait stations in the trees.”

Because the rats climb, Baldwin suggests attaching bait stations to tree branches.

“In addition, elevating the bait stations will eliminate access to bait for many protected mammal species, such as kangaroo rats,” Long said. “The bait diphacinone grain can be purchased from some ag commissioners' offices. This is what Roger Baldwin said they tested and it worked.”

As for the bait stations, they should be designed so that there isn't any spillage for nontarget animals to eat, Long said. 

When roof rat outbreaks occur, rodenticides are often needed to prevent crop damage. However, timing is critical as diphacinone use is highly restrictive and not allowed during the growing season, which is beginning as the weather warms. 

“Check the product label for application instructions,” Long reminds growers. “It's the law.”

Because roof rats climb, UC Cooperative Extension wildlife specialist Roger Baldwin recommends attaching bait stations to tree branches.

Identifying the pest

Roof rat holes are typically 3 to 4 inches in diameter.
One way for growers to identify whether they have roof rats is by the size of the burrows. The nocturnal pests are active above ground in trees and below ground.

“Roof rats can forage away from their nest, so you won't likely find signs of their activity, such as rat droppings outside their burrow, to help identify them,” Long said.

Ground squirrels are active during the day, so they are more likely to be seen, dig holes about 4 inches in diameter and forage above ground near their burrows. Vole and mouse holes are 1- to 2-inches in diameter. Roof rat holes are typically 3 to 4 inches in diameter and might have nut shells in front of them, for example pistachio or almond shells. Rabbits will feed on seedling crops, but do not dig burrows.

Ground squirrels are active during the day and their burrows are 4 inches or more in diameter.
Roof rats are prolific breeders that reproduce year-round, according to Baldwin. Females typically have three to five litters per year with five to eight young, enabling their populations to rapidly increase. The omnivores feed on a wide variety of plant and animal materials, allowing them to adapt to any environment, including urban and agricultural lands.

“Rats are sneaky and hard to spot,” Long said. “If you see damage, including digging in the soil but no wildlife, suspect rats.”

For more information on controlling roof rats, download Quinn and Baldwin's free UC ANR publication 8513, Managing Roof Rats and Deer Mice in Nut and Fruit Orchards at http://anrcatalog.ucanr.edu/Details.aspx?itemNo=8513.

For more information about ground squirrels, download the free UC IPM Best Management Guidelines http://www.groundsquirrelbmp.com or UC IPM Pest Note http://ipm.ucanr.edu/PMG/PESTNOTES/pn7438.html.

 

Posted on Friday, March 9, 2018 at 3:11 PM
Focus Area Tags: Agriculture Pest Management

Almond and Walnut Pest Management Guidelines revised just in time for the holidays

‘Tis the season for baking lots of tasty treats. Breads, cookies, cakes, and candy are just a few that come to mind. What makes many of these treats so tasty is the addition of almonds or walnuts to the list of ingredients.

In California, we are lucky to be at the center of almond and walnut production. According to the California Department of Food and Agriculture's (CDFA's) latest Agricultural Statistics Review, more than 99 percent of the almonds and walnuts produced in the United States are grown in California.

Almond and walnut growers work tirelessly to supply enough nuts to not only satisfy domestic demand, but also for export. Worldwide, almonds rank as the largest specialty crop export. California is the top almond producer in the world, accounting for about 80 percent of all almonds grown. For walnuts, California ranks as the second largest producer in the world. To keep up with this demand, almond and walnut growers must be constantly aware of pests, diseases, and abiotic problems that can affect the tree and growing nuts.

California is the top almond producer in the world, accounting for about 80% of all almonds grown. (Photo: Jack Kelly Clark)

The University of California Statewide Integrated Pest Management Program (UC IPM) has recently published revised Pest Management Guidelines for almonds and walnuts, helping growers prevent and manage pest problems with the most up-to-date information.

Revisions in the Almond Pest Management Guidelines include:

  • A new section on bacterial spot, a new disease of almond in California found in the Sacramento and northern San Joaquin valleys
  • A renamed section on fruit russeting, revised from the old powdery mildew section
  • Significant revisions made to the management section of navel orangeworm, one of the major pests attacking California almonds
  • Improvements on how to do dormant spur sampling section with easier-to-understand information on monitoring and thresholds
Bacterial spot on almond, a new disease of almond in California. (Photo: Brent A. Holtz)

Revisions in the Walnut Pest Management Guidelines include:

  • Updated information on the association between walnut twig beetle and thousand cankers disease
  • New sections for Botryosphaeria and Phomopsis cankers, branch wilt, and paradox canker
  • Significant changes to the walnut husk fly management section
Male (left) and female walnut twig beetles. (Photo: Larry L. Strand)

Both the almond and walnut revised Pest Management Guidelines also include updated information on fungicide efficacy, weed management, and vertebrate management.

Authored by University of California specialists and advisors, the Pest Management Guidelines are UC's official guidelines for monitoring and managing pests in California crops. For more information on pest management in these or other crops, visit the UC IPM website.

Posted on Tuesday, December 19, 2017 at 11:03 AM
Tags: almonds (45), pests (1), walnuts (5)

Internet start-up gleans trust from association with UCCE

Ceres Imaging, an Oakland-based start-up, is working closely with UC Cooperative Extension on its aerial imaging of farm fields, a fact that is helping the company gain trust by association, reported Emma Foehringer Merchant on Grist.org.

Ceres puts equipment on low-flying airplanes to take pictures that will help farmers optimize water and fertilizer application. According to field tests, the imagery works. Since 2014, Ceres has teamed up with UC Cooperative Extension to conduct field trials, including one for the Almond Board that measured the response of nuts to different rates of watering. 

UCCE advisor Blake Sanden conducted trials in an almond orchard like this one to confirm data produced by Ceres Imaging.

In that study, data from Ceres' imaging matched well with the UCCE ground "truthing," said Blake Sanden, UC Cooperative Extension water and soils farm advisor. 

According to the article, "Ceres' relationship with the extension program has helped the company gain trust with sometimes-skeptical farmers." Sanden called UCCE trials the "gold standard of efficacy" for new products in the ag market. 

There is also increased interest in precise water management after years of drought and cutbacks on federal water allocation.

"The attitude (among farmers) used to be, 'I can find water,'" Sanden said. "I would say that 30, 40 years ago, there was an attitude of hope ... that some of the restrictions on pumping water (would) go away." He said growers expected decision-makers "to come back to reality and understand that we've got to make money in California and grow food."

But the restrictions didn't go away. Instead, they became stricter. The uncertainty about water deliveries has made farmers friendlier to new technologies, like the one offered by Ceres.

UCCE advisor Blake Sanden, shown here making a presentation, says UCCE confirmation is "the gold standard of efficacy" for new products in the ag market.
Posted on Thursday, May 4, 2017 at 3:12 PM
Tags: almonds (45), Blake Sanden (2), Ceres Imaging (1)

The 2017 tree nut and fruit season begins with a mixed bag

Wet and wacky winter weather may wreak havoc on the almond crop, but UC Cooperative Extension advisor Franz Niederholzer has promising words for farmers concerned about adequate pollination, reported Heather Hacking in the Chico Enterprise-Record.

“You don't need them to all be pollinated,” he said. A pollination rate of 40 percent would make a great year. Twenty five percent will still produce a decent crop.

The heavy rain, wind and cold temperatures that have characterized January and February 2017 could be overcome with just a bit of warm, sunny weather. In Chico, the weekend of Feb. 11-12 were sunny, as was Saturday the 18th. Those were good days for bees to fly.

Fungus is also a concern, said Danielle Lightle, UCCE advisor in Glenn County. Typically farmers watch the weather and spray fungicides before it rains. However, the persistent rain made orchard floors muddy, unfavorable conditions for moving heavy spray rigs.

Farmers who have been in the business for a while know that the golden rule is to “control what you can and let go of what you can't,” Lightle said.

A bee pollinates an almond blossom under sunny skies.
Posted on Monday, February 27, 2017 at 10:52 AM

Next 5 stories | Last story

 
E-mail
 
Webmaster Email: jewarnert@ucanr.edu