UPDATED: Viticultural area is Kelsey Bench, not Kelseyville Bench.
UC Cooperative Extension study shows smoke damage to grapes not uniform across vineyards
By the time the Mendocino Complex Fires were officially contained on Oct. 4, 2018, five weeks after igniting, they had burned approximately 450,000 acres in Colusa, Lake, Glenn and Mendocino counties, making it the largest wildfire in California history, according to CalFire.
The fire not only destroyed 280 homes and other buildings, its smoke destroyed the market for wine grapes grown in vineyards near burned areas.
Fearing grapes near the fire would impart smoke flavors to the wine, some wineries rejected all fruit from nearby regions of Lake County and Potter Valley, leaving grape growers to hastily find new destinations for their 2018 crop.
“It can be difficult to determine if fruit has been compromised in quality when exposed to wildfire smoke, and whether or not smoke flavors will result in wine when fermented,” said Glenn McGourty, UC Cooperative Extension advisor in Mendocino County.
A new UC Cooperative Extension study shows wind direction and speed, temperature and a vineyard's proximity to an active fire are factors that can help growers and winemakers predict smoke damage to fruit.
“Fruit in my own vineyard, 60 feet across the street from where the fire started, had no smoke damage because the wind was blowing away from it,” McGourty said.
Due to the Mendocino Complex Fires, an estimated $41 million worth of winegrapes, which would have been sold at full price, were impacted – some were sold at a discount, some were sold to other customers, some were custom crushed, while some were left hanging in the vineyard, according to the Lake County Winegrape Commission and Mendocino County Farm Bureau.
The wine industry needed a scientific method of determining whether grapes could be made into a wine untainted by smoke. With funding from the Lake County Winegrape Commission, McGourty formed a workgroup of local growers and winemakers with Anita Olberholster, UC Cooperative Extension enology specialist in the Department of Viticulture & Enology at UC Davis, to research when fruit quality has been compromised.
“The need for industry standards regarding the impact of wildland smoke on winegrapes and the resulting wines has become even more pressing over the past few years,” said Debra Sommerfield, president of the Lake County Winegrape Commission.
Science showed the intensity, duration and timing of the exposure to wildfire smoke affects the grape's uptake. Generally, the closer to harvest, the greater risk to the fruit.
“Both the fruit and wine samples in our study showed a wide range of volatile phenol and glycocide concentrations, indicating that smoke damage to fruit was not uniform across the vineyards sampled,” McGourty said.
Volatile phenols and glycosides create off-flavors
Fresh smoke contains volatile phenols and glycosides that can affect fruit, but these chemicals tend to dissipate in the atmosphere in 1 to 2 hours. Vineyards close to actively burning fires and in the path of fresh smoke are most likely to be affected by smoke taint. Smoke that travels long distances is less likely to affect grapes and the wine made from the fruit.
The combination of volatile phenols and glycosides create “smoke taint” – both aromatic and tactile in the mouth. Wine drinkers may smell smoke or other off flavors and experience a drying of their mouth when high concentrations of the chemicals are present in wine.
“At lower concentrations, smoke taint reminds you of brett-affected wines,” Oberholster explained, referring to the yeast brettanomyces. “There is a shortness of fruit, a kind of dryness in the mouth that you know isn't normal. There may be barely perceptible aromas that aren't normal as well.”
Following wildfire smoke exposure, the researchers sampled fruit from 14 cabernet sauvignon vineyards around the viticultural areas of Lake County, including Upper Lake, High Valley, Big Valley, Kelsey Bench, Red Hills, Lower Lake and Guenoc Valley. As a control, fruit was also sampled from a Napa Valley vineyard that was not exposed to wildfire smoke.
“The volatile phenols guaiacol and 4-methyl guaiacol are detected in the fruit by gas chromatography, so it is possible to sample fruit before harvest to make picking decisions,” McGourty said. “Based on our study, berry sampling and guaiacol/ 4-methyl guaiacol analysis are useful for a quick evaluation of whether or not fruit from a particular vineyard may have the presence of volatile phenols that can potentially result in smoke-affected wine.”
Testing the fruit for volatile phenols and glycosides is both expensive and not completely predictive as standards are not well defined for damage based on smoke chemical concentration, he cautioned.
These two compounds aren't the only ones that cause smoke flavors. More than 70 other compounds in forest fire smoke can also produce undesirable flavors and odors described as “like licking an ash tray, burnt garbage, a burnt potato, a campfire that has been drenched with water.”
The taste test
To assess the levels of the compounds that produce the off-flavors, Oberholster convened a panel of 14 wine industry professionals to taste the sample wines. The wine tasters detected stronger off-flavors in the wines made from riper fruit, which also contained higher concentration of smoke compounds. Less than 6 micrograms per liter of the smoke compounds were difficult for the tasters to detect, leading the researchers to conclude they will have a minimal effect on wine quality.
Smoke from a distant fire
The scientists also looked at the influence of distance from the fire and elevation on smoke taint. They found some vineyards close to the edge of fires and immediately downwind were heavily affected, with the grapes containing high concentrations of the smoke flavor-causing compounds. But they determined elevation was not a factor in smoke flavors in wines.
Wind direction and speed, temperature and vineyard proximity to active fires are highly likely affect whether there will be smoke damage to the fruit, their research showed.
“Smoke generated in the first one or two hours from a wildfire is most damaging to nearby vineyards,” McGourty said. “Even though a vineyard may be enveloped in smoke, if the source of the smoke is from a distant fire, it will probably won't seriously damage the fruit quality because most of the volatile gases are gone.”
Lake County Winegrape Commission's Sommerfield said, “Today, the results of this study are already proving to be useful in deepening our understanding of smoke and the risks it poses to grapes and wine, in enabling grape growers and winery buyers to engage in fruitful discussions and make informed decisions, and, in turn, in helping to propel the development of industry standards and protocols.”
To read more about the study by McGourty, Michael I. Jones, Oberholster and Ryan Keiffer, see the January 2020 edition of Wine Business Monthly at https://www.winebusiness.com/wbm.
“This is a great little study, the first one that I know of that takes a systems approach to evaluating the effects of wildfire smoke,” said McGourty.
Glenn McGourty, UCCE viticulture advisor for Mendocino County, describes for Hannah Bird the UC project to analyze the effect of wildfire smoke on winegrapes.
DPR, Fresno State and UCCE create pesticide safety videos with Hmong farmers
A series of videos describing California pesticide rules and safety in Hmong is now available to view for free online. The videos were produced by California State University, Fresno and UC Cooperative Extension in Fresno County with funding from the California Department of Pesticide Regulation.
The nine-part video series – Complying with Pesticide Laws and Regulations in California – is part of DPR's mission to reach California's farming communities. The videos cover a number of topics including using personal protective equipment, understanding pesticide product labels and application permit requirements.
The innovative educational tool blends peer-to-peer communication with traditional extension methods to include the knowledge and experience of both farmers and extension experts. Hmong farmers featured in the video helped develop scenes in which they educate other farmers, purchase and use personal protective equipment, and interact with extension staff.
“We worked with Hmong farmers who are following pesticide regulations themselves, and are now giving back to educate their peers,” said Ruth Dahlquist-Willard, UC Cooperative Extension small farm advisor, who collaborated on the video production. “Their voices and expertise helped make the scenarios more realistic and accessible to other farmers in the Southeast Asian community.”
Michael Yang, longtime UC Cooperative Extension small farms and specialty crops agricultural assistant, stars in the videos, interacting with farmers based on his extensive experience and trusted relationships in the Hmong farming community, and narrating the educational content in Hmong.
“We hope the videos broaden the reach of our local extension programming to help more farmers understand pesticide regulations and avoid fines, as well as improve their safe handling, selection and use,” said Yang.
Dahlquist-Willard and Yang plan to show the videos at UC Cooperative Extension meetings with Hmong farmers and distribute copies on flashdrives to county Agricultural Commissioner's offices in Fresno County and beyond. The videos are captioned in English.
“DPR works with all types of farmers on pesticide issues and it's critical that they use these tools safely – regardless of the language they speak,” explained DPR Director Val Dolcini. “This video project, the first of its kind to use Hmong speakers, will help foster safer use of pesticides.”
The videos can be viewed at http://bit.ly/fs-dpr-hmong-pesticide-video. The modules in the series cover:
- Introduction to California Pesticide Laws
- Checking for Crops Registered on the Label
- Pests and Application Rates on the Label
- Understanding Signal Words
- Following the Restricted Entry Interval (REI)
- Following the Pre-harvest Interval (PHI)
- Knowing Common Restrictions on the Label
- Using Personal Protective Equipment (PPE)
- Pesticide Permits and Reporting requirements
The project took 700 hours over 18 months to complete, including filming and post-production. Twelve Fresno State students were also involved in producing the videos with the Hmong farmers in Fresno County. Dahlquist-Willard and Yang provided the creative direction in partnership with the farmers involved, and Fresno State's MCJ Multimedia Production Service under Professor Candace Egan brought professional video production and editing skills to make a high-quality finished product. Fresno State student video editor Mali Lee, a fluent Hmong speaker, completed the final edits of the Hmong language material.
“This was one of the most rewarding projects I have ever worked on,” said project director Bill Erysian of Fresno State. “We brought together a unique group of agricultural specialists, students, farmers and video professionals to create a high impact, professional set of educational videos on pesticide compliance for our Hmong farmers here in California.”
DPR has comprehensive pesticide safety and outreach material available in Punjabi, Spanish and English at https://www.cdpr.ca.gov/docs/whs/worker_protection.htm.
- Author: Jeannette E. Warnert
Expanding its expertise in water, soil, pest management, forestry and small farms, five new academics and a county director have joined the ranks of UC Cooperative Extension.
Forest stewardship education academic coordinator
UC Cooperative Extension Central Sierra - Amador, Calaveras, Tuolumne and El Dorado counties
In November 2019, Kim Ingram was named the academic coordinator for forest stewardship education in UC Cooperative Extension's Central Sierra office, which includes Amador, Calaveras, Tuolumne and El Dorado counties.
Previously, Ingram was an academic human resources business partner in UC ANR's Human Resources, leading academic recruitments, analyzing data and managing the academic merit and promotion process. Ingram also served as a community education specialist for the UC Sierra Nevada Adaptive Management Project and Sierra Nevada Watershed Ecosystem Enhancement Project. In that role, she planned, managed and implemented collaborations between UC, agencies, local communities and stakeholders, developed training curriculum and facilitated meetings, workshops and events related to forestry and fire issues in the Sierra Nevada. She is an instructor of record for the UC California Naturalist Program and published a “Natural History of the Sierra Nevada” for use in California Naturalist Program trainings.
Ingram earned a master's degree in education, adult education and training from Colorado State University. She also holds a bachelor's degree in political science with a minor in environmental ethics from Humboldt State University.
Ingram can be reached at email@example.com.
UC Cooperative Extension water and watershed sciences specialist
Based at UC Merced
Safeeq Khan joined UC ANR in October 2019 as a UC Cooperative Extension assistant water and watershed sciences specialist. His research focuses on understanding the interaction between climate and ecosystems to inform land and water management. He uses data-driven numerical models as a research tool to aid in the understanding of watershed systems. As a CE specialist, Khan will develop and carry out collaborative, multifaceted research and extension related to mountain hydrology and their linkage with downstream water uses statewide, with special attention to the Sierra Nevada-Central Valley watersheds.
Prior to joining UC ANR, Khan was a professional researcher and adjunct professor in the department of Civil and Environmental Engineering at UC Merced for five years. Khan brings more than 10 years of research, education and extension experience. He has published more than 35 peer-reviewed journal papers and book chapters, successfully secured several externally funded projects, and presented his work to a diverse range of audiences through digital and print media, workshops and conferences.
Khan has worked very closely with state and federal agencies, local landowners and nonprofit organizations, both in California and elsewhere. He has led several projects related to watershed management, from investigating the impact of non-native tree species and groundwater overdraft on streamflow in Hawaii to mapping hydrological vulnerabilities to climate change in the Pacific Northwest. More recently, his research has been focused on evaluating climate change and watershed restoration impacts on water and forest health and developing stakeholder-driven adaptive decision support tools. He serves as an associate editor for the journal Hydrological Processes. Khan is also a co-director of UC Merced's first Innovations at the Nexus of Food, Energy and Water Systems (INFEWS) grant that addresses connected wildland-storage-cropland subsystems in California.
Khan earned a Ph.D. in natural resources and environmental management from University of Hawaii at Manoa. He also holds a master's degree in agricultural systems and management from Indian Institute of Technology in Kharagpur, India, and a bachelor's degree in agricultural engineering from CSA University of Agriculture and Technology Kanpur, India. In addition to English, he is fluent in Hindi and Urdu.
Khan is based at UC Merced and can be reached at (209) 386-3623 and firstname.lastname@example.org. Follow him on Twitter @safeeqkhan.
Area integrated pest management advisor
UC Cooperative Extension in Sonoma, Napa, Mendocino and Lake counties
Cindy Kron joined UC Cooperative Extension as area-wide IPM advisor for Sonoma, Napa, Mendocino and Lake counties in September 2019.
Before joining UCCE, Kron studied the three-cornered alfalfa hopper as a research entomologist for USDA in their Crop Disease, Pests and Genetics research unit. She tested cover crop species as feeding and reproductive hosts of the three-cornered alfalfa hopper in addition to testing commercially available biocontrol agents against the different life stages of the treehopper. She collaborated with a UC Davis colleague to create a degree day model that predicts the ideal timing to implement cultural control measures with the greatest impact on treehopper populations.
Kron has conducted research on a variety of insects including a two-year vineyard study on the population dynamics of Virginia creeper leafhopper, western grape leafhopper and variegated leafhopper. For her dissertation, she investigated the biology and behavior of the three-cornered alfalfa hopper and their relationship with vineyards. She also studied the effects of temperature on the developmental rate of the invasive European grapevine moth and reared brown marmorated stink bugs for USDA fumigation studies.
“My experiences have motivated me to help growers, stakeholders and the industry solve agricultural pest management problems through applied research by identifying IPM strategies and tactics that are economically feasible and implementable while having the lowest environmental impact,” Kron said.
Kron earned her bachelor's degree in viticulture and enology, with a minor in agricultural pest management, and her doctorate in entomology at UC Davis.
She is based in Santa Rosa and can be reached at email@example.com.
UC Cooperative Extension specialist in soil-plant-water relations
Based at UC Davis
Mallika Nocco joined UC ANR in September 2019 as a UC Cooperative Extension specialist in soil-plant-water relations, based at UC Davis. She earned her bachelor's degree in cultural studies/comparative literature and philosophy from the University of Minnesota-Twin Cities. After five years in the corporate world, Nocco decided to pursue her interest in soil, plants, and the conundrum of sustainable agriculture. She completed a master's degree in soil science and a Ph.D. at the University of Wisconsin-Madison in the Nelson Institute's Environment and Resources Program.
Nocco is based at UC Davis and can be reached at firstname.lastname@example.org. Follow her on Twitter @mallika_nocco.
Director of UC Cooperative Extension in Fresno, Madera, Kings and Tulare counties
Karmjot Randhawa joined UC ANR in September 2019 as the UC Cooperative Extension director for Fresno, Madera, Kings and Tulare counties.
In this newly created position, Randhawa is responsible for the coordination and overall operations of Cooperative Extension programs these Central Valley counties. Unlike traditional county director positions, Randhawa doesn't have academic research responsibilities, so she can focus on overseeing the educational and applied research programs and providing direction and leadership to the academic and support staff within the county extension programs.
Prior to joining ANR, the Central Valley native was the research translation operations manager at George Mason University's Center for Climate Change Communication.
“I look forward to increasing the visibility of UCCE by communicating the positive impacts realized by the people who live in the San Joaquin Valley and benefit from the research activities and contributions of these units,” Randhawa said.
Randhawa received her bachelor's and master's degrees in research psychology at California State University, Fresno, and received her MBA from Johns Hopkins University. She is currently completing the Climate Change and Health Certification Program at Yale University.
Randhawa is based in Fresno and can be reached at (559) 241-7514 and email@example.com.
UC Cooperative Extension assistant specialist for small farms in Santa Clara County
Qi Zhou joined UC ANR in September 2019 as a UCCE assistant specialist for small farms in Santa Clara County. She will work closely with project directors at UCCE Santa Clara to lead research and extension work related to food safety practices on small farms, beginning farmer education and Asian vegetable production.
Prior to joining UC ANR, Zhou conducted research on peach fruit production at Clemson University. At Huazhong Agricultural University, Zhou designed and conducted an experiment that identified the differences between flood-tolerant and flood-susceptible poplar seedlings. Zhou has published several scientific manuscripts and abstracts and given extension presentations.
Zhou earned a Ph.D. in plant and environmental sciences with a minor in statistics from Clemson University, South Carolina, a master's degree in horticulture and forestry from Huazhong Agricultural University, China, and a bachelor's degree in horticulture from Hunan Agricultural University, China. In addition to English, Zhou is fluent in Mandarin.
Zhou is based in San Jose and can be reached at (408) 282-3109 and firstname.lastname@example.org.
Six University of California Cooperative Extension advisor positions have been released for recruitment by UC Agriculture and Natural Resources. Glenda Humiston, UC vice president for agriculture and natural resources, is thrilled to resume strengthening the UC ANR network to address California's current and emerging needs. Due to UC ANR's budget constraints, recruitment for positions identified in the 2018 Position Call had been on hold since July.
The new positions include:
- production horticulture advisor, San Diego County
- agronomy area advisor, Merced County
- livestock and natural resources advisor, Siskiyou County
- nutrition, family and consumer sciences area advisor, San Mateo-San Francisco counties
- vegetable crops and small farms advisor, Riverside County
- pomology and water/soils area advisor, Kings County
“These were difficult decisions to make because while we need the above positions, there are many more needs for both UC Cooperative Extension specialist and advisor positions that continue to wait for additional funding,” Humiston said. “Additionally, while we have grown the UCCE specialist numbers over the last several years, the number of UCCE advisors in the field has steadily declined. For this reason, we are focusing on recruitment of UCCE advisors at this time.”
The farming community lauded adding more county-based UCCE advisors to conduct research and work with farms of all sizes to improve water efficiency, soil health and many other issues.
“Farm advisors represent a vital link from University of California research sites to the state's fields and pastures,” California Farm Bureau Federation President Jamie Johansson said, “and filling these positions will help address a statewide shortage of advisors.
“Knowledge shared by farm advisors through the decades has helped California reach and retain its position as the nation's top producer of high-quality food and agricultural products, and we need to keep that resource alive.”
In January, UC ANR's Human Resources unit will begin recruitment planning for the newly released UCCE advisor positions, which will be posted at https://ucanr.edu/About/Jobs.
Currently they are working on recruitment for the following positions from previous calls:
- viticulture advisor for Kern County
- climate & agriculture project scientist
- human-wildlife conflict advisor for the San Mateo/San Francisco Bay Area
- 4-H STEM academic coordinator
- small farms and specialty crops assistant specialist for Fresno County
“I hope to release five or six more UCCE positions in the spring/summer,” Humiston said. “This is possible, in part, due to the advance notice provided by individuals planning to retire June 2020. In addition, we will complete recruitment of other academic positions currently advertised, including those that are funded through partnerships.”
On Giving Tuesday 2019, donors gave $130,311 over 24 hours for UC Cooperative Extension, statewide programs and research and extension centers that make up the University of California Agriculture and Natural Resources network.
The donations will help UC Agriculture and Natural Resources extend the power of UC research in agriculture, natural resources, nutrition, and youth development to more Californians in their own communities to improve their lives.
“UC ANR researchers and educators are working in every county to bring practical, science-based answers to residents wherever they live in the state.”
Thanks to generous donors, volunteers, staff and board members who gave a total of $40,000 in matching funds, there was an incentive for donors across the state who wanted to double the impact of their gifts.
“We set a goal of collecting a total of $125,000 for 4-H and UC ANR from more than 500 donors on Giving Tuesday,” said Emily Delk, UC ANR director of annual giving and donor stewardship. In all, UC ANR received 580 donations on Giving Tuesday.
Donations are still being accepted to boost UC ANR programs and research for a healthier California. To give, visit http://donate.ucanr.edu.
To learn more about how UC ANR is helping your community, visit https://ucanr.edu/About/Locations and follow @ucanr on social media.