Posts Tagged: Almonds

A hike in navel orangeworm pressure expected later this century due to climate change

Outsized wildfires, rising sea levels and disappearing glaciers are dramatic signs of climate change, but not the only ones. New UC Agriculture and Natural Resources research provides forewarning of a change that will be economically and environmentally costly to California – a fifth generation of navel orangeworm, the most destructive pest of almonds, walnuts and pistachios.

Navel orangeworm (NOW) will be more problematic in the future because of warming temperatures, UC Cooperative Extension scientists report in Science of the Total Environment.

Like most insects,NOW's development rate, physiology, behavior and reproduction are highly dependent on the ambient temperature. When the weather warms in the spring, NOW moths emerge from the nuts left in the tree or on the ground during the winter. After mating, females then recycle those last year's nuts to lay eggs and complete one generation. Adults emerged from that first and subsequent generations then lay eggs on in-season hull-splitalmondnuts, where larvae feeding damages the crop. Typically the pests fly three to four times per year – with more flights in areas with warmer weather.

“Warmer temperatures can result in early activity of the pests in the spring and increased activity during the season,” said Tapan Pathak, the UC Cooperative Extension climate change specialist and the study's principle investigator.

The scientists looked at 10 climate models to determine what nut farmers can expect to face over the next 80 years and applied NOW developmental models to the changing climate. Daily maximum and minimum temperature data were obtained for 1950 to 2005, and future projections stretched to 2100.

“The fifth generation can happen in the next few decades,” said Jhalendra Rijal, UC integrated pest management advisor and co-author of the research. “The climate models suggest that spring will begin earlier. That causes insect activity to start earlier. With increased temperatures through the season, the number of days to complete a generation is less. At the end of 2050 or so, we'll see an extra generation.”

The study focused on 23 counties in the Central Valley, from Shasta County in the north to Kern County in the south, where 1.78 million bearing acres of nut crops are planted. About two-thirds of that acreage is planted to almonds, 20% in walnuts and 16% in pistachios. The tree nut crops were valued at more than $8 billion combined in 2018, according to the California Department of Food and Agriculture.

The completion of the NOW life cycle is faster in pistachio compared to almonds and walnuts, so the potential risk of crop damage and economic loss is higher in pistachio, according to the research report. There are only a few years historically in which the models detected the fifth generation of NOW in Kern County pistachios. The occurrence of the fifth generation in almonds and walnuts was historically nonexistent, but it starts appearing in three southern counties by 2040 and eleven counties by 2100.

“In order to alleviate some of the risks related to navel orangeworm damage to nut crops, it is important to implement integrated pest management practices,” Pathak said.

IPM preventative and control measures include sanitizing the orchard during the winter by removing all the nuts on the ground and in the trees, applying synthetic reproductive hormones to limit the pests' ability to find mates, encouraging natural enemies, judicious of least-toxic pesticides if necessary and harvesting the crop early to avoid a new generation of the pest.

“A better understanding of future navel orangeworm pressure on California's major nut crops can help facilitate and strategize integrated pest management practices in order to minimize production risks,” Pathak said.

The results of the research can also inform growers and pest control advisers about the potential increased threat from other pests as the climate changes.

California nut industry provides funds to hire four UC Cooperative Extension research associates

Four staff research associates will join the ranks of UC Cooperative Extension scientists in the coming months to support nut crop advisors conducting critical research in walnut, almond and pistachio production.

The California Walnut Board, the Almond Board of California and the California Pistachio Research Board together have provided about $425,000 to cover annual salaries, benefits, travel and equipment for the new UC Cooperative Extension staff. Under the terms of the agreement, the new positions will be funded annually for up to three years, pending available funds and success of the program.

“By supporting these new positions in UC Cooperative Extension, the California Walnut Board, the Almond Board of California and the California Pistachio Research Board show their recognition for the value of applied research conducted by our nut crop advisors,” said UC Agriculture and Natural Resources vice president Glenda Humiston. “We are grateful to these industry organizations for this vote of confidence and the generous funding to generate science-based knowledge to apply on California farms.”

The new research associates will each devote time supporting two advisors with tree nut assignments:

• Allan Fulton and Luke Milliron, serving Butte, Glenn and Tehama counties
• Katherine Jarvis-Shean and Franz Niederholzer, serving Colusa, Sacramento, Solano, Sutter, Yolo counties
• Mae Culumber and Phoebe Gordon, serving Fresno, Madera and Merced counties
• Elizabeth Fichtner and an advisor under recruitment, serving Tulare and Kings counties

The arrangement reflects a change in how UC Cooperative Extension supports the agriculture industries in California with applied research. With less funding from its traditional revenue sources – USDA, the state government and counties – advisors cover more territory than in the past. Over the years, they have also taken on an increasing share of UC's applied research mission serving the state's specialty crops industries.

The new staff research associate positions were crafted to attract highly qualified candidates who will support advisors' applied research efforts. Their primary focus will be on assisting advisors with planning, execution and gathering data on experimental and demonstration field trials.

UCCE advisor emeritus Joe Grant, who now serves as production research director of the California Walnut Board, chaired an industry working group that drafted the plan based on advisors' input about their needs.

“Advisors are competent and creative people with the skills and knowledge to do research. They need the same support that researchers on campus have,” Grant said.

The California Pistachio Research Board previously provided funding for a plant pathology researcher and an integrated pest management advisor at the UC Kearney Agricultural Research and Extension Center in Parlier. In addition, the board supported creation of $1 million endowments for a nut genetics researcher and a tree nut soil science and plant-water relations researcher as part of an initiative co-funded by UC President Janet Napolitano.

“We've been concerned for a long time about UC Cooperative Extension's research capacity and infrastructure issues,” said Bob Klein, manager of the California Pistachio Research Board. “This new initiative will increase efficiency and productivity for farm advisors and also reduce their stress from being overcommitted.”

Josette Lewis, the Almond Board chief scientific officer, said the organization depends on UCCE farm advisors for unbiased, quality information about almond production.

“Advisors are a valuable link between UC campuses and growers, not only in doing applied research that helps growers thrive, but in meeting California's goals of environmental and social sustainability,” Lewis said. “The information they generate is shared with a host of ag industry professionals – pest control advisers, crop consultants and people in the private sector who provide services to growers.”

Commodity industry funding for UC Cooperative Extension reflects the value the nut crop industries leverage from one of the strongest agricultural research and extension systems in the world, Lewis said.

The new program is modeled after a pilot project in Colusa County in which the Almond Board provided funding for Niederholzer to hire an intern to support almond research. A young scientist who held the post from 2015-16 was Milliron. In 2017, UC Cooperative Extension named Milliron a sustainable orchard systems advisor for Butte, Glenn and Tehama counties and he will now supervise one of the new staff research associates.

“We had a chance to keep him in the system and capitalize on what he learned during his internship,” Lewis said.

There are other tree nut and fruit advisors in need of research help, Grant said. For example, there are concentrations of tree fruit and nut acreage and growers in Kern, San Joaquin and Stanislaus counties.

“We positioned these four research associates where we heard the need for help was most critical. We can see adding another position or two in the future if funds are available,” Grant said.

Untreatable fungus giving almond producers pause

An airborne fungus from Europe, ganoderma adspersum, has been killing almond trees in the San Jaoquin Valley since it was discovered in the area five years ago, reported John Cox in the Bakersfield Californian.

The fungus rots wood from the inside out, usually weakening the trunk a ground level. 

Three kinds of ganoderma fungus infections were identified recently in California almond orchards; University of California researchers say 94 percent of the cases were of the adspersum variety.

"We are seeing those trees collapsing at 11, 12, 15 years old,” said UC Cooperative Extension orchard systems advisor Mohammad Yaghmour. The infections have results in the removal of orchards at less than half their typical 20- to 25-year life span.

Spraying for the fungal disease is ineffective. Yaghmour believes that in time researchers will identify a root stock that is resistant to the fungus.

UC ANR updates cost estimates for growing almonds

UC Agricultural Issues Center has released new studies estimating the cost and returns of establishing an almond orchard and producing almonds for three growing regions of California.

“These cost studies are valuable for agricultural producers all along the continuum – growers considering entering into a new crop production business, less experienced growers, and those with decades of experience,” said Emily Symmes, UC Cooperative Extension integrated pest management advisor for the Sacramento Valley. “The information in these cost studies allows growers to evaluate their production practices and associated costs relative to an exemplary hypothetical orchard specific to their geographic region, and can help with development of business models, crop insurance and lending.”

In 2018, almonds ranked third among California commodities with almond growers receiving nearly $5.5 billion in cash receipts.

The cost analyses are based on hypothetical farming operations of well-managed almond orchards, using cultural practices common to the region. Local growers, UC Cooperative Extension farm advisors and supporting agricultural representatives provided input and reviewed the methods and findings of the studies.

“The recent almond updates for the Sacramento and San Joaquin valleys reflect costs associated with the continually evolving conditions facing agriculture,” said Symmes, who co-authored the almond cost studies. “Some of the notable updates include labor, irrigation and pest management costs – all integral to producing and delivering a high-quality crop.”

The researchers based one study in the Sacramento Valley, one in the northern San Joaquin Valley and the other in the southern San Joaquin Valley.

The southern SJV study is based on an orchard that uses double-line drip irrigation, whereas the other two locations use microsprinkler irrigation. All are multi-year studies, estimating costs from removal of the previous orchard, through almond orchard re-establishment and the production years. The economic life of the orchards used in these analyses is 23 to 25 years.

Navel orangeworm (NOW) is a major pest in almond production; Symmes and her co-authors describe in detail the pesticide applications and winter sanitation methods for each location for NOW control and include the costs.

The authors describe the assumptions used to identify current costs for orchard establishment, almond production, material inputs, cash and non-cash overhead. A ranging analysis table shows net returns over a range of prices and yields.

The new studies are titled:

• Sample Costs to Establish an Orchard and Produce Almonds in the Sacramento Valley - 2019
• Sample Costs to Establish an Orchard and Produce Almonds in the Northern San Joaquin Valley - 2019
• Sample Costs to Establish an Orchard and Produce Almonds in the Southern San Joaquin Valley - 2019

The studies are available for free download at the UC Davis Department of Agricultural and Resource Economics website at http://coststudies.ucdavis.edu. Sample cost of production studies for many other commodities are also available on the website.

For additional information or an explanation of the calculations used in the studies, contact Donald Stewart at the UC Agricultural Issues Center at (530) 752-4651 or destewart@ucdavis.edu. To contact a local UC Cooperative Extension advisor, find the UCCE office in your county at http://ucanr.edu/County_Offices. The Agricultural Issues Center is a statewide program of UC Agriculture and Natural Resources.

UC offers almond production short course Nov. 5–7

UC Agriculture and Natural Resources will host the UC Almond Short Course Nov. 5-7, 2019, at the Visalia Convention Center.

UC faculty, UC Cooperative Extension specialists and farm advisors and USDA researchers will provide in-depth, comprehensive presentations of all phases of almond culture and production. An optional field tour will be offered on Nov. 8 in Parlier.

The program is based on the latest information and research and will cover the fundamental principles that form the basis for practical decisions. Each session will include Q&A, quality time with instructors and networking opportunities. The full agenda is at https://ucanr.edu/sites/almondshortcourse/2019_Agenda.

This year's short course offers an in-depth field tour at the Kearney Agricultural Research and Extension Center on Friday, Nov. 8. For an additional fee, participants can learn firsthand about topics ranging from orchard establishment and management to integrated pest management. See the tour agenda at https://ucanr.edu/sites/almondshortcourse/2019_Field_Tour.

Registration is $900, discounts are available until Oct. 21. On-site registration will be $1,000.

Registration includes:

• Three full days of instruction with more than 35 presentations
• Binders containing presentations
• Three lunches and two receptions
• DPR (PCA) & CCA continuing education credits (pending approval)
• Option to add Field Tour for $65

For more information, visit https://ucanr.edu/sites/almondshortcourse. Register at https://ucanr.edu/survey/survey.cfm?surveynumber=27971.

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