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

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 (16), pests (1), walnuts (4)

Planet-friendly orchard recycling makes money sense

The numbers are beginning to trickle in confirming UC Cooperative Extension advisor Brent Holtz' hunch. Chipping and returning expired almond orchards into the soil where they grew is not only environmentally sound, it is economically smart. 

(View a three-minute video of the machinery in action at the end of this post.)

A commercial grinder can be used to chip whole almond trees.

After about 20 years, almond orchards' productivity and vigor begin to decline. Most farmers remove the old trees and plant younger, more vigorous replacements to keep up almond production.

In the past, old trees were easily and cheaply disposed of: they were pushed into a pile and set on fire. Air quality regulations have all but eliminated the practice.

At first, grinding the trees and sending the chips to a co-generation plant was a farmer's preferred option. The companies that used biomass for electricity generation paid an acceptable sum – about $600 per acre – for the wood chips, which helped offset the cost of chipping and hauling the trees off the property.

However today, electrical utilities are looking for clean, renewable energy sources like wind and solar. 

“Cogeneration plants burn wood biomass, which still releases carbon dioxide and methane into the atmosphere,” Holtz said. “Many are losing contracts and shutting down.”

The modified manure spreader in the background spreads wood chips, while the roto tiller mixes wood chips into the ground.

Holtz sought another cost-effective alternative, and believes incorporating the wood into the orchard floor may be the answer. Although initially expensive, adding $400 per acre to the $600-per-acre cost of chipping the old trees, the organic matter and nutrients released by the woodchips over time appear to boost yield to a level that covers a chunk of the cost.

In preliminary research, Holtz found that almond orchards where old wood was incorporated into the soil were averaging about 1,800 pounds of meat nuts per acre, while the orchard where old trees had been burned averaged 1,600 meat nuts per acre.

“Almonds sell for about $2 to $3 per pound. To have a 200-pound average yield increase per acre, you've made up the cost of incorporating the wood in just one year,” Holtz said. “It would be even more affordable if farmers can sell carbon credits for the biomass that they sequester in the ground.”

Note the size of chipped almond trees compared to the boots on the ground.

Holtz recently demonstrated two approaches for incorporating almond trees into the soil. The first, which was also used in the study eight years ago at the UC Kearney Agricultural Research and Extension Center in Parlier, is a 50-ton rock crusher called the Iron Wolf. It lumbers down the tree row, grinding up whole trees in place, then reverses over the mangled wood to incorporate it into the ground.

“We thought this one-machine process was the answer,” Holtz said.

G & F Ag Services in Ripon, which has made a business of chipping and hauling almond wood to a co-generation plant, conceived another plan. It modified a manure spreader to spray ground-up wood chips across the orchard floor. Holtz worked with Manteca farmer Louie Tallerico to give the new process a spin.

“This required five different machines working together compared to one Iron Wolf. In this process, the trees have to be excavated by an excavator, then hauled to the wood chipper with a front-end loader. The trees have to be fed into the wood chipper, then the wood chips have to be spread on the orchard floor,” Holtz said. “Another machine, a disk or roto tiller, incorporates the chips into the soil.

The five machines combined are a tremendous time saver.

“The Iron Wolf could do about two acres per day,” Holtz said. “This process can do 15 or 20 acres per day.”

Farmers and industry professionals gather at a UC Cooperative Extension field day at the Tellarico Farm in Manteca, Calif.

Tallerico opened his farm for a field day in October to demonstrate parts of the process to other farmers and industry representatives. Participants stood on layer of fresh-cut wood chip mulch where a full-grown almond orchard stood just weeks before. The spreader demonstrated the ease with which the wood chips are dispersed evenly across the orchard floor, and a tiller mixed the wood chips into the soil.

The Tellarico orchard will now be the site of research – funded by the California Almond Board – to be conducted by Holtz and a team of scientists interested in documenting the growth and development of the new almond orchard among the remnants of its predecessor.

“In the previous study, three years after incorporating the old trees into the soil we started to see the nutrient benefit,” Holtz said. “This was done at Kearney, where we incorporated a peach orchard that had about 30 tons of organic matter per acre. Almond trees are larger, so here we have 86 tons of organic matter being returned to the soil.”

In the new study, the scientists will determine whether the nutrient benefits found in early research still hold true, whether the wood chips in the soil stunt the new orchard or boost its growth, whether the new orchard suffers from replant disease, and the fate of good and bad nematodes (tiny soil-borne worms) in the new orchard.

“We will also study the carbon budget and continue the life cycle assessment of almond with this practice, to better understand the benefit of these processes,” Holtz said.


Posted on Thursday, October 20, 2016 at 1:23 PM

UCCE is taking the melodrama out of almond orchard recycling

An alternative to the Iron Wolf (shown above) for orchard recycling will be demonstrated at an Oct. 13 field day in Manteca.
UC Cooperative Extension will demonstrate a kinder, gentler – plus cheaper and more effective – method of recycling an almond orchard at a Manteca field day 10 a.m. to 12 noon Oct. 13.

Almond farmers will remember a UCCE demonstration last February when the 50,000-pound Iron Wolf rolled like a tank through an almond orchard in Chowchilla, ripping whole trees into shreds and incorporating the wood into the soil.

Researchers are now considering a less dramatic approach to removing an old orchard and incorporating the wood chips into the soil onsite. Combining a traditional horizontal chipper with a wood chip spreader modified for this purpose can be a viable alternative to the now-mostly banned burning of old orchards or transport of almond tree residue to co-generation facilities that convert biomass to energy.

“It's still cheaper for the farmer if he or she can sell the wood chips for co-generation,” said Brent Holtz, UC Cooperative Extension advisor in San Joaquin County and the research leader. “But co-generation plants are closing and our research is showing that incorporating the biomass into the soil has many benefits.”

When the wood breaks down, it returns nutrients to the soil. Organic matter increases, resulting in carbon sequestration, important for moderating the release of greenhouse gases into the atmosphere that may contribute to climate change.

The chipper and spreader combination pencils out at about $1,000 per acre, while the Iron Wolf costs about $1,500 per acre.

“The Iron Wolf turned out much more expensive and slower than we anticipated,” Holtz said. “It could only grind up and incorporate about two acres of trees per day, while the horizontal chipper can chip 15 acres per day. With the chipper and spreader combination, the chips do have to be disked in, which most growers can easily do.”

The whole orchard recycling project was funded by the Accelerated Innovation Management program of the Almond Board of California.

Whole Orchard Recycling Demonstration
11630 S. Airport Way (near Roth Road), Manteca, Calif.
Thursday, Oct. 13, 2016

10 a.m.
Whole almond orchard recycling and the effect on second generation tree growth, organic matter and soil fertility presentation
Brent Holtz, Ph.D., UC Cooperative Extension advisor

10:30 a.m.
Kuhn & Knight Wood Chip Spreading Demonstration
Randy Fondse, G & F Ag Services, Ripon, Calif.

11 a.m.
Morbark Horizontal Chipper Demonstration
Randy Fondse, G & F Ag Services, Ripon, Calif.

Posted on Friday, October 7, 2016 at 1:31 PM

UC offers Almond Production Short Course Nov. 8-10

Almond growers are invited to attend a short course on all phases of almond culture and production in Modesto on Nov. 8-10, 2016.

The integrated orchard management program, sponsored by UC Agriculture and Natural Resources and UC Davis, will provide participants with the practical, field-level information they need to successfully farm almonds. UC Davis faculty and UC Cooperative Extension specialists and farm advisors from throughout California will present their latest research.

Three full days of instruction include more than 35 presentations on orchard planning, evaluation and management of soil, tree training, irrigation, economics of almond farming, pest management and other topics.

New and experienced growers as well as other industry members interested in commercial almond production are welcome to attend. There will be opportunities to network with other participants and presenters, along with a chance to have questions answered by professionals in the industry.

The almond short course will be held at the Modesto Centre Plaza at 1000 L Street in Modesto. Registration for the program is $950 until Oct. 24 and includes full course participation, course materials, three lunches and two receptions, and continuing education credits.

For more information and to register, visit http://ucanr.edu/sites/almondshortcourse.

If you have questions about the almond short course, please contact Lauren McNees at (530) 750-1257 or anrprogramsupport@ucanr.edu.


UC Agriculture and Natural Resources researchers and educators draw on local expertise to conduct agricultural, environmental, economic, youth development and nutrition research that helps California thrive. Learn more at ucanr.edu.

Posted on Wednesday, October 5, 2016 at 1:41 PM
Tags: Almonds (16)

UC releases new cost studies for growing almonds

Almonds growing on the tree.
UC Agricultural Issues Center has released three new studies on the cost and returns of growing almonds in the Sacramento and San Joaquin valleys. One study focuses on organic production of almonds.

The cost analyses are based on hypothetical farm operations of well-managed orchards, using practices common to each region. Growers, UC ANR Cooperative Extension farm advisors and other agricultural associates provided input and reviewed the methods and findings of the studies. Two studies estimate the costs for establishing and producing almonds grown in the northern San Joaquin Valley and Sacramento Valley using micro-sprinkler irrigation. These are multi-year studies, estimating costs from previous crop (orchard removal) through orchard establishment and the production years.

The study for organic almonds takes into consideration growing conditions in the northern San Joaquin Valley and complying with the National Organic Program. This study is based on an orchard that began the transition period and certification as organic after the second year of establishment. The trees in this study are in production and at full bearing. This organic almond orchard uses a solid-set sprinkler system.

The economic life of the orchards used in this cost analysis is 25 years. The authors describe the assumptions used to identify current costs for the almond crop, material inputs, cash and non-cash overhead. A ranging analysis table shows profits over a range of prices and yields. Other tables show the monthly cash costs, the costs and returns per acre, hourly equipment costs, and the whole farm annual equipment, investment and business overhead costs.

Almond orchard in bloom.
The new studies are titled as follows:

  • Sample Costs to Establish an Orchard and Produce Almonds in the San Joaquin Valley – North- 2016
  • Sample Costs to Establish an Orchard and Produce Almonds in the Sacramento Valley – 2016
  • Sample Costs to Produce Organic Almonds in the San Joaquin Valley - North - 2016

Free copies of these studies and other sample cost of production studies for many commodities are available. To download the cost studies, visit the UC Davis Department of Agricultural and Resource Economics website at http://coststudies.ucdavis.edu.

The cost and returns program is funded by the UC Agricultural Issues Center, which is part of UC Division of Agriculture and Natural Resources, and the UC Davis Department of Agricultural and Resource Economics.

For additional information or an explanation of the calculations used in the studies, contact Don Stewart at the Agricultural Issues Center at (530) 752-4651 or destewart@ucdavis.edu, or Christine Gutierrez at (530) 752-1520 or cagut@ucdavis.edu

Posted on Friday, April 29, 2016 at 2:16 PM

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