- Author: George Zhuang
30,000 acres of San Joaquin Valley vineyards have adopted mechanization using UCCE research-based guidelines, potentially saving $15 million per year and promoting economic prosperity in California.
Grape is the second largest commodity of California agriculture in terms of value ($6.25 billion in 2018) with approximately 900,000 acres. Currently, increasing labor costs and severe labor shortages are starting to damage long-term grape farming profitability and competitiveness. Full mechanization on wine grape vineyard can reduce the production cost per acre from $3,000 to $2,500 per acre, which represents about 20% reduction of production cost. However, wineries and juice processing plants have concerns about grape and juice quality from mechanization.
How UC Delivers
UCCE Fresno and UC Davis have been working on research projects to identify the best strategy for mechanical pruning, leafing and shoot thinning at San Joaquin Valley, North Coastal, and Napa Valley regions. Research findings have identified the best guidelines for adopting vineyard mechanization and confirmed that mechanization has no negative effect on grape and wine quality, but improves the grape and wine quality. The research results have been shared with growers and industry personnel through meetings, field demonstration, newsletter, and professional society conference.
“We don't really have an R&D arm, so we really rely on George and Cooperative Extension to provide viticultural knowledge and methods to help us achieve our production goals,” Nick Davis, southern valley vineyard manager of The Wine Group, the second-largest U.S. wine company, told Growing Produce. “We really enjoy our collaboration with UC Extension — through them we can attain the best quality grapes in our vineyards.”
Over 30,000 acres of wine grape in San Joaquin Valley has been converted into some sort of mechanization based on UCCE's research and extension of findings. Mechanization can save $500 per acre for growers on production costs based on 2019 UC cost studies; thus, potentially saving $15 million per year. UCCE's viticulture research and extension contributes to increasing agriculture efficiency and profitability, and the public value of promoting economic prosperity in California.
Vineyard mechanization is the win-win-win situation: growers can improve their farming margins, wineries and juice processing plants can have reliable supply and better quality, and average consumers can enjoy better wine and more healthy grape products at the decent price. There is potential for wider adoption of vineyard mechanization across California's grape growing regions. The Wine Group (the second largest winery in US), and other industry partners, have had positive feedback and indicate they will adopt the mechanization into the current farming practices.
- Author: Lynn Wunderlich
Agriculture today faces a huge challenge in labor shortages. Only recently have foothill growers been looking at investing in mechanical tools to help them get the work done. Last month I held a field day in collaboration with Patrick Tokar, viticulturalist for Rombauer, the same Napa Valley Rombauer that recently acquired the old Renwood winery and tasting room in Amador county. (I have a friend who only drinks Rombauer chardonnay-a classic buttery chard that's been
Rombauer's foothill operation, they've been growing Zinfandel in El Dorado county since about 2007, recently acquired a Pellenc "suck and pluck" style of leafer-a machine
In addition to leafing, Rombauer has been using remote sensing and aerial imaging to help them make decisions on the farm. I invited UCDavis Biological and Agricultural Engineering Specialist Ali Pourezza to explain the fundamentals of remote sensing. Ali is a recent addition to our ANR Specialist group and is a whiz in creating models of virtural orchards and vineyards and using sensing technology to solve agricultural problems (check out his video of our field day on Ali's twitter!).
Ali explained to the group that light behaves in 4 different ways when it interacts with plants: it is reflected (which is easy to measure), absorbed (which can be calculated based on reflection), scattered or transmitted. When using remote sensing, a multi-spectral camera is mounted on either a UAV or a plane, and images taken which give information dependent on the spectral resolution (or band width) of the camera. Models are developed to interpret this information, and, (this is super important), calibrated with accurate ground truth data. The calibration is also critical, and needs to include a "radiometric" calibration-that is, a calibration with the sun's position during the time of imaging (which won't be the same on any given 2 days).
NDVI (normalized digital vegetation index), is the most common and uses near-infrared to red light wavelengths in a scale to tell if green (healthy) vegetation is present or not. Ali said that NDVI values below 0.1 indicate no vegetation, 0.2-0.5 indicate sparse vegetation, and 0.6-0.9 indicate healthy vegetation. Other, more advanced indices use other spectral bands, such as NDRE or "red edge". Ali has been doing some research on using hyper-spectral (thousands of bands!) imaging to detect N2 (nitrogen) deficiency in vineyards. Working with Viticulture Specialist Matthew Fidelibus, who ground-truths the sensing data by taking vine petioles for nutritional analysis, Ali is developing a model to predict
Rombauer is using Ceres Imaging to do their sensing and Jenna Rodriguez (one of our own UCDavis grads now working for Ceres) also spoke at my field day. After Ali's technical "nuts and bolts" talk, Jenna explained how her company uses remote sensing and modeling to interpret the images provided to clients such as Rombauer. For example, a blue line on a thermal imaging map was interpreted to be a leaky irrigation pipe. Low chlorophyll in one area of the vineyard could possibly be soil related.
The tools of precision agriculture and remote sensing can save labor and help pinpoint the need for applications such as fertilizer. Yet, there's no replacement for "keeping one foot in the furrow", as the late J.C. Walker of UW-Madison, my alma matter, used to say. Until next time...
- Author: Jeannette E. Warnert
UC Cooperative Extension specialist Kaan Kurtural is managing a vineyard at the 40-acre UC Oakville Field Station in Napa County with virtually no manual labor, reported Tim Hearden in Capital Press.
“We set this up to be a no-touch vineyard,” Kurtural said. “All the cultural practices are done by machine.”
Kurtural's original intent was to help farmers deal with labor shortages, but the trial also produced superior winegrapes.
“When I took the job at the University of California, the labor situation started to get worse,” Kurtural said. “If we didn't have people to prune grapes, we weren't able to finish pruning. So we said, ‘We are a research station, let's develop a solution.'”
In the research vinyard:
- A machine equipped with telemetry and GPS sensors prunes the vines
- Soil and canopy data are collected manually
- Spurs and suckers are thinned with a specially designed pruner
- Clusters are thinned mechanically
- The grapes are harvested mechanically
“We can do all the practices mechanically now,” he said. “There was no economic need to do this previously, but now there is.”
Kurtural attributes the winegrape quality improvements to the tall canopy, which protects grapes from sun damage. The system also uses less water.
For complete details, watch a 40-minute lecture by Kaan Kutural online
- Author: Jeannette E. Warnert
The story was based on research by agricultural economists at UC Davis and the U.S. Department of Agriculture. The report, titled “Labor Trajectories in California’s Produce Industry,” found that changes in the way immigrant labor is regulated in the U.S. would increase the cost of labor for California's $20 billion fresh fruit, nut and vegetable industry.
“California’s produce industry depends on a constant influx of new, foreign-born laborers, and more than half of those are unauthorized laborers, primarily from Mexico,” the UC Davis news release quotes Phillip Martin, a professor of agricultural and resource economics.
“The cost of hiring these laborers will likely rise as the U.S. government ramps up enforcement of immigration laws by installing more physical barriers along the U.S.-Mexico border and requiring more audits of workers’ I-9 employment verification forms,” Martin said.
Read more in the current issue of the ARE Update.