California Agriculture
California Agriculture
California Agriculture
University of California
California Agriculture

Current issue and featured articles

April-June 2018
Volume 72, Number 2

Peer-reviewed research and review articles

Employment and earnings of California farmworkers in 2015
by Philip Martin, Brandon Hooker, Marc Stockton
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A review of wage data from agricultural employers suggests that most California farmworkers were employed for less than a full year in 2015.
The average employment of hired workers in California agriculture (NAICS 11) rose over 10% between 2005 and 2015, when some 16,400 agricultural establishments hired an average 421,300 workers who were paid a total of $12.8 billion, which was 27% of the state's $47 billion in farm sales. This means that a full-time equivalent (FTE) employee would earn $30,300, implying an hourly wage of $14.55 for 2,080 hours of work. We extracted all Social Security numbers reported by California agricultural establishments and found that the average annual pay received by the 848,000 workers who had at least one job on California farms was $20,500 in 2015, two-thirds of the average annual wage of an FTE worker, reflecting some combination of lower wages and less than full-year work.
Automated lettuce thinners reduce labor requirements and increase speed of thinning
by Elizabeth Mosqueda, Richard Smith, Dave Goorahoo, Anil Shrestha
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Automated thinners were as accurate in thinning lettuce as manual thinning, produced comparable yields, and were more than three times faster than thinning crews.
Salinas Valley lettuce growers are adopting automated lettuce thinners to improve labor efficiency. We conducted field studies in 2014 and 2015 to compare the time involved in automated and manual thinning of direct-seeded lettuce and any differences in lettuce quality and yield. We recorded the number of doubles (two closely spaced plants) left behind after thinning, time taken to remove the doubles, final crop stand, efficiency in weed removal, crop yield and disease incidence. Using an automated thinner in place of manual hoeing reduced the thinning labor requirement from 7.31 ± 0.5 person-hours per acre to 2.03 ± 0.5 person-hours per acre. Automated thinning left more doubles than manual thinning, resulting in additional time to remove them, but was overall more labor-efficient and had no impact on yield or disease incidence.
Wild pigs breach farm fence through harvest time in southern San Joaquin Valley
by Michael D. White, Kayla M. Kauffman, Jesse S. Lewis, Ryan S. Miller
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Camera traps recorded 860 wild pig encounters at Laval Farms during the harvest season for grapes and pistachios, most of them at night.
Wild pigs cause around $1 billion of damage to agriculture in the United States each year — foraging on crops, breaking branches and vines, and damaging irrigation lines and fences — but little is known about how and when they access agricultural fields. We used wildlife camera traps to document and describe wild pig access to two fenced southern San Joaquin Valley farms. Pigs breached fences around agricultural fields, especially during the harvest period when crops were ripe, and almost exclusively at night, outside of the regulated, daytime recreational pig hunting period. GPS data from an adult boar revealed that pigs may travel long distances from wildlands to reach crops. The results of our case study suggest that increasing monitoring and maintenance of fences during the harvest season and removing pigs that have learned to access farms may help reduce pig damage to agricultural fields. The results also suggest a formal scientific investigation of risk factors and strategies to reduce wild pig damage is warranted.
Central Coast growers' trust in water quality regulatory process needs rebuilding
by Ann Drevno
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A 2015 survey of growers showed their trust of the regional water board had decreased since 2006, even though there had been more frequent communication.
Growing evidence of agricultural water pollution in California's Central Coast even after the implementation of tough water quality regulations has increased the pressure on regional stakeholders. Previous research has shown that collaborative relationships between growers and regulators can motivate growers to make management decisions that benefit the environment. However, informal evidence suggested trust might have been eroding between growers and the Central Coast Regional Water Quality Control Board (CCRWQCB, the regulator) since 2004, the year the first legislation went into effect. Using a survey conducted in 2015, interviews and in-depth document review, this study assesses growers' trust of and communication with other agricultural groups and water quality regulatory agencies, specifically CCRWQCB. Survey results were compared to results of the same survey sent out in 2006. Results corroborate other research — growers' trust of most regional agricultural groups was closely correlated with frequency of communication. However, growers' trust of CCRWQCB did not correspond to the relatively high contact frequency and had declined since 2006. The literature on rebuilding trust suggests ways forward for CCRWQCB.
Teens-as-teachers nutrition program increases interest in science among schoolchildren and fosters self-efficacy in teens
by Virginia L.J. Bolshakova, John Gieng, C. Sheena Sidhu
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An after-school nutrition program increased children's preferences for gardening, cooking and science, and teen teachers reported an increase in health self-efficacy.
The Healthy Living Ambassador Program brings health, teen leadership, and teamwork to California's elementary school gardens through interdisciplinary UC Cooperative Extension collaboration, community-based partnerships and teen teaching. During spring 2015, teen ambassadors trained by Extension educators and volunteers at UC Elkus Ranch in San Mateo County taught nutrition science, food cultivation and healthy living skills in an 8-week, garden-based, after-school nutrition and physical education program for elementary school children in an urban setting. We conducted a pilot study using a mixed-methods approach to measure and explore the program's impact on children's vegetable selection and consumption preferences, as well as perceived self-efficacy in teen healthy living behavior. The children trended toward an increased preference for gardening, cooking and science, and teens displayed an increase in perceived health self-efficacy.

News and opinion

The race in the fields: Imports, machines and migrants
by Philip Martin
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Four ways farmers are responding to the tightening labor market.

Next-generation mechanization
by Jim Downing
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New advances in image-recognition technology and robotics are reducing the need for manual labor — and potentially herbicides as well.
Research highlights
by Jim Downing
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Briefs of recent AES and UCCE research papers on tree mortality, sugary drinks, mountain runoff and wild bees.

Early view articles

Groundwater sustainability in the San Joaquin Valley: Multiple benefits if agricultural lands are retired and restored strategically
by Rodd Kelsey, Abby Hart, H. Scott Butterfield, Dan Vink
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Restoring habitat in retired farmland could reduce water demand and provide ecosystem services for farmers and local communities.
Proactive biological control: A cost-effective management option for invasive pests
by Mark S. Hoddle, Kevi Mace, John Steggall
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Proactive biocontrol could accelerate responses to invasive pests in urban areas — where pesticide use may be unpopular — before they spread to agricultural areas.

Survey of the pathogen of Alternaria late blight reveals different levels of carboxamide fungicide resistance in the main pistachio producing regions of California
by Paulo Lichtemberg, Ryan Puckett, Daniel Felts, Yong Luo, Lorene Doster, David Rodriguez, Themis Michailides
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Resistance was greatest in counties at the northern and southern ends of the Central Valley, where weather conditions are conducive to pathogen infection.
Alternaria late blight (ALB), caused mainly by the fungal pathogen Alternaria alternata, is an important pistachio disease that causes severe tree defoliation and fruit shell staining. Its control relies on multiple fungicide sprays, including carboxamide fungicides. In 2015, we surveyed 35 orchards representing nine pistachio producing counties of California to determine the current situation of Alternaria resistance to four widely used carboxamide fungicide active ingredients. This survey showed that isolates collected in the northern (Tehama, Glenn and Colusa counties) and southern (Tulare, Kings and Kern counties) Central Valley presented higher frequencies of carboxamide resistance than isolates collected from orchards in the central region (Fresno, Madera and Merced counties). The number of carboxamide usages in a year is the main factor determining elevated resistance. By extracting the A. alternata DNA and sequencing the carboxamide target genes, we evaluated the prevalence of specific molecular alterations (mutations) associated with carboxamide fungicide resistance. Finally, we identified cross-resistance patterns among different carboxamide fungicides, leading to recommendations about combinations to avoid.


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