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The End of Open Ag Burning in the Central Valley and the State

Under SB 703 (Florez) Chapter 481, Statutes of 2003, open burning for agricultural crops is phased out under a prescribed schedule. This schedule will result in the near-complete prohibition of agricultural open burning in the Central Valley beginning Jan. 1, 2025 (all photos courtesy Fowler Brothers Farming.)

In the next two years, California’s Central Valley will experience a transformational change in agriculture: the end of open agricultural burning. It is likely that other regional air districts around the state will adopt a similar prohibition of open agricultural burning in the years to follow.

Under SB 703 (Florez) Chapter 481, Statutes of 2003, open burning for agricultural crops is phased out under a prescribed schedule. This schedule will result in the near-complete prohibition of agricultural open burning in the Central Valley beginning Jan. 1, 2025.
In preparing for this, the California Association of Winegrape Growers (CAWG) worked with other agricultural industry associations in 2021 and successfully advocated in the State Legislature for nearly $180 million in funding for the San Joaquin Valley Air Pollution Control District. This one-time influx of money in part provides funding for the District’s Alternatives to Agricultural Open Burning Incentive Program. This stipend program is intended to help growers pay the high costs of alternatives to open agricultural burns during the phaseout.

For decades, the disposal of old orchards and vineyards has commonly involved burning. For vineyards, the materials used in trellising, such as end posts, t-posts and wire have created unique challenges in how to dispose of vines when removed. That is why up and down the Central Valley, you may see piles of pulled vineyards left sitting waiting to be disposed of.

In 2003, opponents to SB 703 warned of the very situation in which we now find ourselves. The analysis by the Assembly Committee on Natural Resources, dated June 30, 2003, stated, the following:

“Bill opponents state that while the agricultural community is willing to pursue means to reduce or eliminate burning when feasible, it is important that alternatives to burning be established BEFORE the prohibition is enacted.”

Unfortunately, that advice was not heeded.

CAWG will be advocating in the legislature in 2024 to obtain additional funding to develop viable alternatives, like the air curtain burner pictured here, for disposing of vineyards.

To address this situation, CAWG will be advocating in the legislature in 2024 to obtain additional funding to develop viable alternatives for disposing of vineyards. However, this will be difficult as almost every alternative comes with unique challenges. The alternatives and associated challenges are outlined as follows:

Chipping and Mulching: This alternative involves the grower to either hire a company to chip or mulch the piles of vines on-site or ship those piles to a facility equipped for chipping and mulching.

There are three specific challenges with this alternative:
Economics. Most of the machines used to chip, mulch or grind vines don’t work well with metals. This means all metal would need to be removed first, which can be a very costly endeavor. Additionally, if the vines are being shipped to a facility, shipping costs can also be expensive.

Disease. When old vines are removed due to disease, chipping and mulching is not a viable option as this would potentially result in putting disease back into the soil or spreading the disease to nearby vineyards. The federal Tree Assistance Program (TAP) provides financial assistance to eligible growers to replant. A condition of the TAP program is the diseased vine cannot be reincorporated into the soil and best practices prioritize burning.

Market Demand. Increased forest management (preventing fires) and the recent prohibition of putting food and other organic waste into landfills has resulted in a substantial increase in the supply of compost, mulch, wood chips and other similar groundcover. This means if a grower decides to dispose of old vines through chipping and mulching, no one may be waiting to buy that material. So, what is the grower to do with that material? While there is a beneficial use of this material in a new vineyard, there is only so much a grower can use.

Air Curtain Burners, also called FireBoxes: These act as an air pollution control device by reducing the particulate matter, smoke or black carbon created by burning wood waste. This alternative to traditional open burning mitigates the amount of smoke released from open agricultural burning. This also creates a valuable byproduct that can be tilled into the soil. The downside is that while some growers can afford this equipment, most cannot. Additionally, there is limited availability of these burners.

Low-Smoke Ag Burning: This is an important option (for 2024 only) in dealing with vineyard management waste. Low-smoke agricultural burning, when using best practices, takes into consideration concerns of public health as well as climate change. The challenge here is how long a grower needs to wait for approval of a burn day. Depending on several meteorological factors and how many people want to burn in that area, a grower with a permit to burn could wait for several months to get approval, and that grower is not guaranteed to be able to burn their full permitted amount in one day.

Biochar: This is one of the smartest alternatives that also offers incredible benefits. One ton of biochar is equivalent to three tons of CO2 sequestered. By turning old vineyards into biochar, carbon remains trapped in its solid form, thus creating a carbon-negative cycle. However, few Pyrolysers (an oven that creates biochar through pyrolysis) exist in the Central Valley. Additionally, there are economic challenges in shipping.

Biomass: Vines can be used as alternative fuels within energy conversion chains, driving renewable energy exploration as an alternative to traditional agricultural biomass burning. The ability to convert grapevine biomass residues into energy is potentially a valuable alternative to explore in the future. However, there would need to be an expansion of markets and availability. Unfortunately, policymakers in Sacramento currently do not see biomass as an effective tool in fighting climate change and protecting clean air.

CAWG has created a hotline for its members who find they have reached a dead end in getting approval to burn. It is recommended that CAWG members diligently go through the steps provided on cawg.org’s Ag Burn Hotline Webpage (under the Resource Tab) before completing the form for CAWG’s assistance.

Fire Insurance a Moving Target

Some owners of vineyards and wineries in high-fire-risk areas are finding it difficult to keep themselves on fire insurance plans as providers continue to pull out and prices increase.

Driving up Soda Canyon Road on Napa’s east side, the neighborhood under the Vaca mountains looks different these days. Gone are many of the old wood frame houses, replaced today with new, boxy homes built of fire-resistant materials.

The October 2017 Atlas Fire was the big changemaker. The fire destroyed 781 buildings and over 51,057 acres of vegetation.

Chris Vandendriessche remembers what life was like before the fire when his family’s winery, White Rock Vineyards, had just one insurer. In 2017, the family lost all the structures on their property, including the 1870’s stone winery that had been converted into a family home for his parents (who founded the family winery), the modern winery a few hundred yards away and the small tasting room adjacent to it.

With money from their insurance claims from Travelers Insurance, the stone house innards were built anew, preserving the stone structure on the building’s outer shell. The winery caves were restored.

But today, Travelers no longer provides their coverage.

“Before the fire, we could have one carrier that insured the entire property, liability, equipment, all the houses, caves, the entire thing was at one company,” said Vandendriessche. “After the fire, nobody wanted to take on that much risk because that meant you were exposed to all the potential damages in a fire. And since then, we’ve had to take eight or nine companies, each one taking a little tranche of the insurance needs of our business.”

But each year, the family still must seek new coverage and new insurers.

“Every year since the fire, two or three of those companies have backed out, and we have to find new ones. The prices have tripled for less coverage. So, that’s our insurance picture.”

The Vandendriessche’s insurance agent, Jim Stetson, Agency co-owner of Leavitt United Insurance Services, deals with properties all over the state. He says the rising rates are highly localized and that insurance rates for vineyard and winery owners in other parts of the state have not been affected by the wildfires.

“For somebody with little to no wildfire exposure, we can still get basically the same kinds of programs that we had in the past,” he said. “It depends on the wildfire risk, the property values and loss control, and brush mitigation. If you’re in American Canyon or Lodi or Sacramento or somewhere like that, the wildfire concern isn’t going to be really an issue. But in a lot of the other areas, you are going to be exposed to that.”

Wine Warehouse Insurance Affected
It also depends on where wine is stored, Stetson said.
“Aggregation can be an issue; that’s where carriers only want to have a certain amount of limit in one area so that if there’s some kind of catastrophic wildfire event, they’re not losing it all in one event. So, they don’t want to have too much value, say over $100 million, in one five-mile area.

“We see that at the wine warehouses in American Canyon right now, where there’s aggregation issues with certain carriers where they have too many clients storing wine or producing wine in one location.”

Insurance Tied to Bank Loans 
The insurance issue is complicated because it isn’t just about insurance. Insurance is linked to winery finance since banks require insurance to lend money.

“2017 brought increased awareness of the problem, and that’s when the insurance industry started pulling out,” said Michael Miiller, director of government relations at the California Association of Winegrape Growers (CAWG).

“Basically, where our growers are is they have a property that has a structure on it. And if they have any kind of line of credit already lending at all, they have to have proof of insurance as a condition of that lending, which means they have to have insurance.”
“We’re in a crisis situation,” he said.

Mixed Reviews for the FAIR Plan
The state of California has stepped in to create the insurer of last resort: the FAIR Plan. FAIR Plan’s policy numbers more than doubled between 2018 and 2022 from 127,000 to 272,000 (including homeowners as well as businesses.)

“Right now, it’s the only option available to people, to many, many people,” said Miiller. “And when your safety net is all you have, that’s not sufficient. They have a limit to how much they can cover.”

In March 2023, the California Department of Insurance announced it would up FAIR Plan caps for commercial businesses coverage amounts “from $8.4 million to $20 million per location, and under its Division II Business Owners Program, from $7.2 million to $20 million per location,” according to a department press release.

Stetson explained that the FAIR Plan is not a state run program but is run by the insurance companies themselves. “A lot of people think it is [state-run], but it’s a pool of all the admitted carriers doing business in California.”

That means each new change requires negotiations between the department and the FAIR Plan.

Reducing on-property fire risks may improve coverage options in the eye of the insurer, but there is no guarantee of return on investment.

By summer 2023, the department had still not implemented the increases announced in March and said in an email to Grape & Wine the higher limits would most likely be available by end of 2023. That leaves many businesses exposed again during the 2023 vintage.

“The FAIR Plan does not cover things like faster water damage or falling objects, freezing pipes,” said Stetson, “so there’s some gaps there.”

He said commercial insurers are starting to fill in some of the gaps. “That’s starting to come back online and provide a little bit of relief.”

Miiller pointed out that even when the $20 million limit is implemented, the amount is per policy, not per structure. “It would be better if it were per structure,” he said.

The CAWG official criticized the state’s insurance regulators for being slow to act.
“We’re looking at how they set rates, we’re looking at the expediency of rate approvals and those kinds of things. There’s a lot that can be done at the Department of Insurance to speed things up. And they’re just not doing it. When you look at when Lara expanded the FAIR Plan, it took them forever to approve their rates.”

“When there’s no product on the market, growers have no options,” he said.

Still, despite wildfires in Oregon, the situation is quite different there, Miiller said.

“You can find growers in Oregon who aren’t having near the problems that they’re having in California. Their regulatory system is entirely different.” That’s because Oregon does not set commercial insurance rates.

The Crisis Continues… for Some
Miiller warned that the crisis, however unevenly distributed it is, is far from over.
“If we don’t start looking at this like the emergency situation that it is, we are quickly going to see a bunch of industries that are going to pay some serious consequences because they can’t buy insurance. Insurance isn’t an option. You have to have it to be in business. If it is not available, the dominoes start falling.”

“So, from my perspective, I think there really needs to be somebody to step up and say, ‘Hey, we have an emergency. And I’m going to implement these emergency actions to start to address this problem.’”

Yet, when it comes to insurance, some areas of the state are stable, said Stetson. “For folks in the Central Valley, if there’s no wildfire risk, the options are pretty much what they were [before 2017]. If there’s wildfire risk, then we have to start getting more creative.
“If there’s no wildfire risk, that’s the carrier’s main concern. We have seen a little bit of a rate increase, but there’s still a lot of carriers playing in the space.”

Reducing Risk
What can property owners do to reduce risk in the eyes of insurers?

“It’s a moving target,” Stetson said. “Defensible space is always the first thing that people do, cutting back brush, removing low hanging branches and getting ladder fuels off the property or away from the buildings. That’s definitely helpful.

“Some people have contracted private firefighting companies to consult. Some will spray fire retardant seasonally around the production buildings, and then they sometimes have them on a retainer to come in…so if there’s a wildfire event, they will help defend the property.”

Sprinklers make sense, he said, but there’s no guarantee installing them will bring a return on the investment. “Unfortunately, it’s difficult to ask somebody to spend that much money because it’s not necessarily a guarantee of an offer of coverage. The insurance companies can make somebody put in a six-figure sprinkler system, and then that same carrier that asked him to do that next year could pivot,” he said.

“A lot of people in the brushy areas are stuck in the process,” he added.

Another limitation of the FAIR Plan: It doesn’t cover wine in tanks. “Anything not bottled yet is excluded from coverage,” said Stetson. “So that’s a pretty big issue for people because typically, once it’s case goods, they can move it to a third-party storage location and find palatable, affordable coverage from an admitted carrier.”

According to the California Department of Insurance, counties where 25% or more homes are in high fire risk, these are the top-ranked counties, by highest exposure first: Tuolumne, Trinity, Nevada, Mariposa, Plumas, Alpine, Calaveras, Sierra, Amador, El Dorado, Mono, Lake, Mendocino, Siskiyou, Butte, Lassen, Shasta, Tehama, Santa Cruz, Humboldt, Napa, Del Norte, Modoc, and Placer.

Sustainable Story Series: Part 2 Planting Trees with a Bottle of Wine: Social Responsibility in the Wine Industry

From water application tools and strategies in the vineyard to capturing, treating and reusing winery wastewater, sustainable wine brands use practices that minimize their water use, optimize efficiency and reduce groundwater pumping (all photos courtesy Shale Oaks Winery.)

While our planet’s nickname “the Blue Planet” might imply that water resources are plentiful and available, this is not actually the case. Over 97% of Earth’s water is unusable salt water, and 2% is unavailable freshwater stored in glaciers and ice caps. This means less than one percent is freshwater that is accessible to humans to fulfill our daily water needs.

USDA’s Erika Cross gave this staggering analogy: “…if the world’s water supply were 26 gallons, our useable supply of freshwater would be half a teaspoon” (Cross 2022).
Of all our water daily uses, from hydrating ourselves and our pets to washing our hands and our cars, water for agricultural crops is one of the most important and demanding.
With the country’s population growth of nearly 100 million between 1980 and 2015, how can it be that water withdrawals for irrigation were relatively steady during that time span? The USGS posits the effects could be attributed to water conservation efforts and greater water use efficiencies (USGS 2018).

Managing agricultural water use in a responsible way can have a positive impact on water conservation while also maintaining a stable food supply for years to come. Growers can use responsible water management strategies that conserve and optimize their use, ones that increase water efficiency without decreasing crop yield. The sustainable winegrowing community does just that.

When rain falls on the roofs of Shale Oak’s winery and tasting room, it is directed through a water passage that flows to a water feature. When it fills up, the overflow goes to a sump pump, where it begins its journey to the vines.

Water Sustainability in Viticulture
From water application tools and strategies in the vineyard to capturing, treating and reusing winery wastewater, sustainable wine brands use practices that minimize their water use, optimize efficiency and reduce groundwater pumping.

Agriculture can feel like a battle against natural elements. Growers must learn to work with elements out of their control, including wind, frost, degree days or a family of ground squirrels that decides to call their vineyard home. Although the same can be said for precipitation, supplemental water application is one of the few inputs the grower has significant control over.

So, how does a vineyard manager know when to irrigate the vineyard and how much water to apply? As well as using visual cues from the vines themselves, sustainable winegrowers use hard data from plant and soil moisture monitoring devices to understand how their crops and the land respond to their practices. Using this data, they make informed irrigation decisions and only apply water when it is needed.

Low-volume irrigation systems are one of the most impactful water conservation tools in the grower’s toolbox. Drip irrigation is a sustainable winegrower’s go-to method. This type of irrigation system typically uses an impressive 20% to 50% less water per-acre than a sprinkler system (EPA 2017).

In a drip system, emitters are placed along an irrigation line that runs along a vine row a few inches above the soil. The emitters slowly drip water directly onto the planted areas at the base of the vine. This is a contrast to sprinkler systems, which spray high volumes of water over large areas, both planted and not. The slower, more targeted application of water delivered by drip means a greater percentage of what is applied is actually used by the crop, less water is lost through leeching and runoff, and water isn’t applied to areas that don’t need to be irrigated.

At the top of Shale Oak’s hill sit five 100,000-gallon water cisterns. This is where the rainwater from the wet season is pumped and held until the dry season to drip irrigate the 5-acre vineyard.

Responsible water management does not stop in the vineyard. It can take anywhere from 2 to 20 gallons of water to produce 1 gallon of wine (Wine Business Analytics 2014) depending on a winery’s water management practices. Between using water to clean and sanitize equipment, as a wine additive and as a processing aid, gallons can add up.
Sustainable winemakers don’t let the runoff water from tasks go to waste; they recycle it. Winery wastewater can be stored in an irrigation pond or aboveground or belowground holding tanks on the property. Wherever it is stored, wastewater must be treated before being reused.

After proper treatment, recycled water can be used for more cleaning and sanitizing of winery equipment, as an equipment coolant, for frost protection in the vineyard and even for irrigating grapevines and landscaping. If you’re concerned over whether the quality of grapes and composition of the soil could be harmed by recycled water, there’s no need to fret; several studies show that when managed correctly, winery wastewater has no negative effects on the health of grapevines or vineyard soils (Hirzel et. al. 2017; Buelow et al. 2015).

Sustainability in Action: Shale Oak Winery
It’s not just winery wastewater that is captured for later use. With proper architectural planning, rainwater that falls on roofs and driveways can also be collected and used for growing wine grapes. Some wineries are designed with rainwater capture in mind, like Shale Oak Winery in Paso Robles, Calif.

When rain falls on the roofs of Shale Oak’s winery and tasting room, it is directed through a water passage that flows to a water feature. While this water feature offers patio tasters a sense of serenity, it was designed to be more than a visual pleasantry. When it fills up, the overflow goes to a sump pump, where it begins its journey to the vines.

Shale Oak captures most of the rainwater that falls on their property through this roof collection system, and by utilizing the natural flow of the terrain. The water that falls on their grounds, driveway and parking lot are diverted to numerous waterways that lead to an underground cistern. All this water that would otherwise have run off their property will join the water collected from the roofs to deficit irrigate their vines.

At the top of Shale Oak’s hill sit five 100,000-gallon water cisterns. This is where the rainwater from the wet season is pumped and held until the dry season. During the hotter, drier months when the vines are in critical growing stages, all the rainwater they captured is carried out to drip irrigate their five acres of vines and hydrate their landscaping.
Since this water capture strategy was designed into every element of their layout, Shale Oak significantly reduces their pumping needs. In fact, Sean Walter, assistant winemaker, stated, “Our 500,000-gallon capacity, most of the time, can get us through the whole growing season if we have a significant rainfall throughout the wintertime.”

Learning how responsible producers like Shale Oak Winery go the extra mile to protect natural resources has a myriad of positive effects on the whole food system. It fosters deeper connections between agricultural producers and consumers, brings attention to sustainably minded growers and their good work, and helps consumers understand more about the agricultural systems we depend on every single day.

“Food disconnect” is a term used to describe the average consumer’s lack of knowledge about where their food comes from and how it’s made. When it comes to wine, most people only see the finished product: what’s in their glass.

If your wine brand practices sustainability, there’s yet another level to this disconnect with your customers. While consumers name food and beverage as one of the most important industries when it comes to sustainability, more than one in four U.S. adults said they don’t know what makes a product sustainable (Morning Consult 2022).

This highlights an opportunity to showcase the time and careful consideration that went into your wine’s production. By highlighting your dedication to sustainability, you create a deeper connection with your customers. Wine drinkers gain valuable (and engaging) insights into agriculture. Plus, it lets them know that when they support your brand, they also contribute to a more sustainable food system.

In the next issue of the Sustainable Story Series, we share the story of a San Luis Obispo, Calif. winegrower who unintentionally discovered a unique pest mitigation strategy while developing a vineyard planting method that significantly conserves water by using everyday hardware store materials.

New Bottle Bill Deadline is Approaching Fast, and Action is Required

California Redemption Value labeling must be “clearly, prominently and indelibly marked,” according to CalRecycle.

Wineries have until Jan. 1, 2024 to sign up with CalRecycle to start reporting each month the number of wine bottles, cans and bag-in-box items they produce. It’s all part of the new bottle bill, SB 1013, passed in 2022.

The new law going into effect has two important deadlines for producers.
Part 1, due Jan. 1, 2024, is reporting and paying a small fee per container.
Part 2, due July 1, 2025, is labeling all containers with recycling redemption language, following specific CalRecycle mandated guidelines.

The overwhelming majority of wine and liquor containers sold are glass bottles: 87% by units and 99% by weight. PET plastic bottles make up 9% of wine and liquor units sold (less than 1% by weight). Aluminum cans make up only 2% by units and are negligible by weight, while 3% are cartons and foil pouches that are not eligible for California Redemption Value.

Part 1: Reporting and Paying 
Before this new law went into effect, consumers could turn in bottles and cans for non-alcoholic beverages for redemption and receive 5 or 10 cents back per item. The issue is that most did not visit a specific recycling center to get those nickels and dimes, but rather deposited their empties in municipal waste pickup programs.

The new law expands returnables to wine and spirits containers. It also requires retailers to do a better job of accepting returnables.

Then two months after the start of the Jan. 1, 2024 reporting deadline, producers will be required to pay fees based on the numbers in those reports.

The idea is to close the loop between producers and the potential waste they create. Redemption increases recycling rates, experts say. It also creates better-quality glass returns, researchers report, and that makes this recycled glass more attractive for reuse by glass manufacturers.

Examples of approved label samples.

According to CalRecycle, the bill will bring 4,200 California wineries into the fold and is expected to add 1.1 billion wine and spirits containers to recycling. That’s an overall increase of 4%, a department spokesperson said.

The CalRecycle registration page has details. The agency also has representatives available to assist in filling out registration forms.

Beginning in March 2024, producers will begin paying “processing fees.” The price is not fixed but is very low. Currently, the fee is $0.00452 per bottle, $0.00005 per plastic container and $0.00762 for a box or equivalent.

Tasting rooms in California do not need to report or pay processing fees, but any out-of-state wineries selling to Californians must report monthly and pay processing fees.

Examples of labels that were not approved.

Part Two: Labeling Changes
After completing the first phase of reporting and paying fees, the second big deadline takes place 18 months later on July 1, 2025. By then, wine and spirits containers sold in California must be labeled with the California Redemption Value (CRV) code.

Consumers will then begin paying CRV deposits of five cents for containers under 24 ounces, 10 cents for containers of 24 ounces or more and a flat rate of 25 cents for bag-in-box packaging (regardless of size).

CalRecycle offers wineries five options for the message to display on the container: California Redemption Value, CA Redemption Value, California Cash Refund, CA Cash Refund or CA CRV.

There’s more information available in the CalRecycle webinar, posted on its YouTube channel, and website instructions provide requirements and example how-to’s.

The labeling must be “clearly, prominently and indelibly marked,” according to the website.
For glass and plastic, the message needs to be on the container body label or secondary label. The text height should be 3/16 inches, or it can be 1/8 inches if it is in a contrasting color to the background and nearby text.

Examples of temporary label options.

For aluminum cans, the message must be on the top lid. If the top is more than two inches in diameter, the message must be 3/16 inches in height. If the top is 2 inches or less in diameter, the message must be 1/8 inches in height.

The agency is still working on details for box, bladder and pouch product labeling.
No monetary value appears in the messaging as that is subject to change in the future, CalRecycle said.

The CalRecycle website has do’s and don’ts examples posted on its website.

The End Goal: More Efficient Glass Reuse
According to Scott Defife of the Glass Packaging Institute, “California bottles have 40% recycled content. Oregon bottles have 70% recycled content. Washington bottles have 50% recycled content.”

CalRecycle hopes the redemption program will increase the recycling rate to 80% and increase glass reuse by glass manufacturers.

Industry researchers from the Container Recycling Institute say glass returned outside the consumer redemption system (where it is mixed in with other recycling items) is dirtier and costs $20 a ton to recycle. That’s in contrast to cleaner glass handled through redemption centers where it’s worth $20 a ton and is attractive to glass manufacturers.

CalRecycle online webinar: youtube.com/watch?v=x50d5FYvQdA
CalRecycle’s Beverage Distributors and Manufacturers: calrecycle.ca.gov/BevContainer/BevDistMan/
Bottle Bill resource page: wineinstitute.org/our-industry/bottle-bill/

Mechanical Leaf Removal is More Effective than Regulated Deficit Irrigation to Improve Fruit Quality While Maintaining Yield

Figure 1. Overly vigorous vine due to abundant winter precipitation and overirrigation (all photos courtesy G. Zhuang.)

Berry sugar and anthocyanin accumulation are key factors in determining the fruit quality of red wine grapes in the San Joaquin Valley (SJV), where >70% of California wine grapes are grown (California Grape Crush Report 2022). Hot climates are not ideal for red Bordeaux cultivars such as Cabernet Sauvignon and Merlot as anthocyanin accumulation is inhibited. However, fruit quality might be improved with certain management practices, including deficit irrigation and leafing. Previous research in the SJV demonstrated that moderate irrigation deficits can improve grape yield and quality in addition to saving water (Williams 2012). Mild or moderate irrigation deficits promote yield formation due to increased bud fruitfulness and decreased fungal disease pressure. Sustained deficit irrigation (SDI) of 70% to 80% evapotranspiration (ETc) was found to balance economically sustainable yield, fruit quality and water-savings goals (Williams 2010). Abundant winter precipitation and overirrigation cause grapevines to grow excessively, shading the fruit, directly reducing quality and favoring the development of fungal diseases (Mendez-Costabel et al. 2014) (Figure 1).

Figure 1. Overly vigorous vine due to abundant winter precipitation and overirrigation (all photos courtesy G. Zhuang.)

Years like 2023 might remind growers that managing water and canopy size to improve canopy microenvironment and enhance spray coverage will reduce fungal disease pressure (Figure 2). However, severe water deficits pre-veraison significantly impair grapevine vegetative and reproductive growth, photosynthesis and fruit maturity (Levin et al. 2020).

This year in Akif Eskalen’s powdery mildew trials, grape clusters in the untreated controls had 100% disease incidence.
Figure 2. Heavy powdery mildew infestation on Chenin Blanc (left) and botrytis bunch rot on Pinot Gris (right).

Figure 2. Heavy powdery mildew infestation on Chenin Blanc (left) and botrytis bunch rot on Pinot Gris (right).Removing leaves in the fruit zone is another beneficial practice growers may do to improve fruit quality. Leafing increases fruit exposure which may directly improve fruit quality, create a microenvironment that discourages powdery mildew and bunch rots, and improve spray coverage (Austin and Wilcox 2011) (Figure 3). Leaf removal is most practiced in cool climates as overexposure can easily reduce fruit quality in a hot climate. However, studies on leaf removal in a hot climate also showed similar benefits as reported in cooler climates (Cook et al. 2015). As with deficit irrigation, the timing and intensity of fruit zone leaf removal determines the potential impact on grapevine yield and fruit quality at harvest. In a cool climate, basal leaf removal prior to bloom may reduce berry set, thus lowering yield (Acimovic et al. 2016). Effects on berry set depend on the extent of leaf removal and the weather (Frioni et al. 2017). In hot climates, mechanical fruit zone leaf removal prior to bloom had no effect on berry set or yield (Cook et al. 2015). In addition to the potential to reduce set in cool climates, leaf removal prior to bloom can increase berry total soluble solids, anthocyanin content and berry aroma compounds (Ryona et al. 2008). Recently, mechanical fruit zone leaf removal has gained popularity due to labor shortage and increased labor cost in California (Kurtural and Fidelibus 2021). Years like 2023 which came with abundant winter precipitation, delayed harvest and cool temperatures might require additional fruit-zone leaf removal to open the canopy and increase spray coverage to help control fungal diseases.

Figure 3. Leaf removal around grape cluster (left). Spray coverage increases with leaf removal (right).

Three-Year Field Study
Aiming to find the “sweet spot” of water management and leaf removal on yield, sugar and anthocyanin accumulation of red wine grape in hot climates, we conducted a three-year field study on Cabernet Sauvignon grown in Madera as Cabernet Sauvignon is believed to be one of the most challenging varieties to be grown in the SJV due to lack of berry color at harvest.

Figure 4. Clemens roll-over leaf plucker with a sickle-bar sprawl clipper (left) and mechanical leaf removal at full bloom of Cabernet Sauvignon (right).

The experiment was conducted in a commercial vineyard located in Madera on fine sandy loam soil. 10-year-old Cabernet Sauvignon vines on Freedom rootstock with 4’x10’ spacing and Northeast-Southwest row orientation were used for the experiment. The grapevines were quadrilateral cordon trained with a 24-inch cross-arm to 48-inch height above vineyard floor with a pair of catch wires above the cordons. A two (deficit irrigation) × three (leaf removal) factorial split-plot design was applied for three seasons: 2018 through 2020. Two irrigation treatments were applied: 1) sustained deficit irrigation (SDI): water was maintained at 80% of weekly crop evapotranspiration (ETc) through the growing season; 2) regulated deficit irrigation (RDI): water was maintained at 50% ETc from berry set to veraison then switched back to 80% ETc until harvest. ETc was calculated using the equation of ETc = ETo × Kc (Williams 2010). On top of irrigation treatments, we applied three timings of mechanical leaf removal: 1) bloom, 2) berry set and 3) no leaf removal. Leaf removal was applied to both sides of the canopy using a roll-over leaf plucker with a sickle-bar sprawl clipper adapted for a sprawling-type canopy (Model EL-50, Clemens Vineyard Equipment, Woodland, Calif.) (Figure 4).

Results and Discussion
RDI reduced yield by 15% compared to SDI mainly due to smaller berries and clusters (Tables 1 and 2). Leaf removal did not significantly affect yield. Our result confirms that severe water deficit, like 50% ETc, pre-veraison, can result in significant yield loss. Contradictory to the previous field observation, bloom leaf removal had no effect on yield, and growers should be less worried about yield loss due to bloom leaf removal than severe deficit irrigation.

Berry soluble solids (Brix) were affected mainly by irrigation treatments in our study. RDI consistently reduced soluble solids each year (Table 2). Interestingly, we found that the effect on Brix depended on the interaction of leaf removal and water management (Table 3). Leaf removal increased Brix when vines were not water stressed or mildly stressed like when SDI was applied whereas leaf removal reduced Brix when vines were severely water stressed like when RDI was imposed. This implies to growers that if sugar is your biggest concern, you should water vines maintaining mild or moderate vine water stress and remove fruit-zone leaves.

Berry anthocyanin content is critically important for red wine grapes. RDI increased berry anthocyanins by 14% in comparison of SDI, and bloom and berry set leaf removal increased anthocyanins by 19% and 13%, respectively, compared to no leaf removal control (Table 2). This means the 14% increase in anthocyanin concentration from the RDI treatment is proportional to the decrease in berry weight and yield. So, there is no net gain of anthocyanins per berry associated with the RDI irrigation treatment. Bloom leaf removal increased anthocyanins by nearly 20% with no yield reduction and that means bloom leaf removal provides a net gain of anthocyanins per berry.

Bloom leaf removal was more effective than pre-veraison RDI at improving berry Brix and anthocyanins without adversely affecting yield. Given the significant reduction on yield from severe deficit irrigation and the low economic return per ton of fruit in the SJV, bloom mechanical leaf removal coupled with SDI of 80% ETc could be a useful practice for SJV growers.

Acimovic, D., Tozzini, L., Green, A., Sivilotti, P., and Sabbatini, P. (2016) Identification of a defoliation severity threshold for changing fruitset, bunch morphology and fruit composition in Pinot Noir. Australian Journal of Grape and Wine Research, 22: 399– 408. doi: 10.1111/ajgw.12235.
Austin, C and Wilcox, W. (2011) Effects of Fruit-Zone Leaf Removal, Training Systems, and Irrigation on the Development of Grapevine Powdery Mildew. Am J Enol Vitic. June 2011 62: 193-198.
Cook, M., Zhang, Y., Nelson, C., Gambetta, G., Kennedy, J., Kurtural, K. (2015) Anthocyanin Composition of Merlot is Ameliorated by Light Microclimate and Irrigation in Central California. Am J Enol Vitic. 66: 266-278.
California Sustainable Groundwater Management Act (SGMA) 2014 Sustainable Groundwater Management Act (SGMA) (ca.gov)
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Frioni, T., Zhuang, S., Palliotti, A., Sivilotti, P., Falchi, R. and Sabbatini, P. (2017) Leaf Removal and Cluster Thinning Efficiencies Are Highly Modulated by Environmental Conditions in Cool Climate Viticulture. Am J Enol Vitic. 68: 325-335.
Kurtural, K and Fidelibus, M. (2021) Mechanization of Pruning, Canopy Management, and Harvest in Winegrape Vineyards. Catalyst: Discovery in Practice. 5: 29-44.
Levin, A., Matthews, M., and Williams, L. (2020) Effect of Preveraison Water Deficits on the Yield Components of 15 Winegrape Cultivars. Am J Enol Vitic. 71: 208-221.
Mendez-costabel, M., Wilkinson, K., Bastian, S., Jordans, C., Mccarthy, M., Ford, C., and Dokoozlian, N. (2014) Effect of increased irrigation and additional nitrogen fertilisation on the concentration of green aroma compounds in Vitis vinifera L. Merlot fruit and wine. Australian Journal of Grape and Wine Research. 20:80–90.
Ryona, I., Pan, B., Intrigliolo, D., Lakso, A., and Sacks G. (2008) Effects of Cluster Light Exposure on 3-Isobutyl-2-methoxypyrazine Accumulation and Degradation Patterns in Red Wine Grapes (Vitis vinifera L. Cv. Cabernet Franc). Journal of Agricultural and Food Chemistry 56 (22), 10838-10846.
Williams, L. (2010) Interaction of rootstock and applied water amounts at various fractions of estimated evapotranspiration (ETc) on productivity of Cabernet Sauvignon. Australian Journal of Grape and Wine Research. 16:434–444.04
Williams, L. (2012) Interaction of applied water amounts and leaf removal in the fruiting zone on grapevine water relations and productivity of Merlot. Irrig Sci. 30: 363-375.
Williams, L. (2014) Effect of Applied Water Amounts at Various Fractions of Evapotranspiration on Productivity and Water Footprint of Chardonnay Grapegrapevines. Am J Enol Vitic. 65: 215-221.

A Vintner from the Ground Up

Matt Trevisan and his daughter Gabrielle in the Linne Calodo tasting room (photo by C. Merlo.)

Back when Matt Trevisan was new to California’s wine industry, he received a piece of advice he’s never forgotten: “Wine is made in the vineyard.”

Those words stayed with him as he made his way, year by year, into viticulture and winemaking. Trevisan had no family background in the business, but he had fallen in love with all things wine while attending California Polytechnic State University, San Luis Obispo. He soon was apprenticing at wineries in the nearby Paso Robles area, picking grapes, driving forklifts, learning how varietals were grown, how wine was produced and bottled.
In 1998, Trevisan and his wife Maureen took a leap of faith and started their Linne Calodo winery. Two years later, they bought their first piece of land, located in the Willow Creek District just west of Paso Robles. It was the beginning of their estate vineyard, but it wasn’t until 2005 that they were able to plant its first five acres. In 2012, they bought 48 more acres nearby, calling it Stonethrower Vineyard and planting vines a year later.

Carefully maintained vineyards surround the entrance to Linne Calodo winery west of Paso Robles (photo by C. Merlo.)

Trevisan had already begun questioning the accepted belief that California blended wines were inferior to varietal wines. He set out to craft his own red blends and create wines with high-integrity growing and winemaking. Over the next few years, Trevisan and Linne Calodo would specialize in limited red blends, helping break new ground in Paso Robles winemaking.

Out of Linne Calodo’s passion-driven production came Rhone-variety blends with names like Rising Tides and Overthinker as well as Zinfandel-driven blends such as Cherry Red. Trevisan’s most popular wine, a blend of Zinfandel, Syrah, Grenache and Mourvédre, was created through a long, frustrating process he feared was a mistake. Instead, the result was a delicious blend, which he aptly named Problem Child.

But Trevisan never forgot that wine begins in the vineyard. The California native practices what he calls “nature positive” farming. It’s based on age-old ways of farming that work with the land’s limited resources. Linne Calodo vineyards rely on natural solutions and manual labor instead of chemicals and carbon-heavy activities.

Matt Trevisan, here in his winery cellar, plays a hands-on role in Linne Calodo’s operations (photo courtesy Linne Calodo.)

Over the past 25 years, Trevisan has made his mark. In July, he was named San Luis Obispo County’s 2023 Winemaker of the Year. The recognition came from the Paso Robles Wine Country Alliance in partnership with the San Luis Obispo Coast Wine Collective, the independent Grape Growers of the Paso Robles Area, The Vineyard Team and past award recipients. The annual award recognizes dedication, stewardship, innovation and leadership in the country’s wine community.

Just before this year’s grape harvest began, Trevisan shared more of his story with Grape & Wine.

Q. Where does your winery’s name, Linne Calodo, come from? What does it mean?
Linne Calodo is a series of calcium-based soils, mapped out by the U.S. Geological Survey, that predominate here on the west side of the Santa Lucia Mountains. When we chose our winery’s name, we looked for something unique that represented our neighborhood.

No-till farming is practiced at Linne Calodo’s vineyards (photo courtesy Linne Calodo.)

Q. How did your life’s path lead to winemaking?
I am a first-generation vineyard farmer and winemaker. I went to Cal Poly intending to major in aeronautical engineering. But then I switched to biochemistry. Along the way, I met multiple individuals involved in the wine industry, including people connected with Fetzer and Robert Mondavi. While at Cal Poly, I helped with harvest on the James Berry Vineyard. I really fell in love with this business. After I graduated in 1995, I went to work for Justin Winery, doing an apprenticeship there. The next seven years of my life were with Justin Winery and Wild Horse Winery and Vineyards, where I managed the warehouses and did any job I had to do.

Q. When did you buy your first vineyard property?
While I was working full-time at Wild Horse, my college roommate and I started making wine after hours. With the approval of Kenny Volk, who owned Wild Horse at the time, we used the facility every day from 10 p.m. to 7 a.m. When we started Linne Calodo in 1998, a lot of people, including other winemakers, helped out, both picking fruit for us and helping us process. I used the bottling line at Wild Horse to bottle the first vintages of Linne Calodo. That was a great time. In 2000, before the market really moved, my wife Maureen and I bought a property of 77 acres here in Paso Robles. It wasn’t until 2005 that I was able to plant my first estate vineyards; it was just five acres.

Carefully maintained vineyards surround the entrance to Linne Calodo winery west of Paso Robles (photo courtesy Linne Calodo.)

Q. You started that from the ground up?
Yes. In 2012, I bought another 48 acres across the road. Starting in 2012, we put vines in the ground on that and did full development. There was no power on that property, no wells, no roads or anything. I didn’t start with a chest full of money. It’s been a slow grind.

Q. What do you mean by “nature positive” in your vineyards?
It’s to let Nature take its course. I’m really just a steward of the land. We farm no-till, no herbicides. We spray only organics for mildew control. It really goes hand in hand with my winemaking style. When I pick grapes, it’s about letting them go through a natural process to become wine.

Q. Are you doing anything differently from five years ago?
No-till agriculture is something I had tried before and couldn’t figure out, using no herbicides out there. It’s a very labor-intensive process we’ve enacted, which is basically treating our vineyard like a home garden for our winemaking. We’re out there hand-weeding pretty much every square foot and trying to get invasive species out by hand.

Visitors enjoy both Rhone-variety blended wines and the exterior setting of Linne Calodo’s tasting room. (Photo courtesy of Linne Calodo)

Q. Do you irrigate your vineyards or dry farm?
I have both. My Zinfandel and Grenache vineyards are dry farmed. I’ve been experimenting over the last two decades how to create sustainability of grapevines. What’s the spacing of the grapevines? What are the irrigation or non-irrigation methods? I may irrigate when planting a vineyard but then pull back and end up on a vigorous enough root stock and clonal selections to where I’m really working backwards on the vine. It’s just a lot of fruit thinning and shoot thinning along the way to get the grapes to maturity.

Q. Why has Linne Calodo focused on limited red blends?
When I started making wine, people were still acidulating wines, changing tannin contents. It was fairly chemistry heavy. I understand chemistry and, yeah, I can manipulate things. I can do organic synthesis and create a pharmaceutical. But winemaking is not about that. It’s more like cooking. It’s more like putting different spices together to change the flavor characteristics. When you grow different grapes, you grow different flavors, with different acid and tannic levels. It really opens up the door to creating a composition that is exciting, artistic and enjoyable for everyone without just doing it through the use of chemistry manipulation.

“I’m really just a steward of the land,” says Matt Trevisan (photo courtesy Linne Calodo.)

Right now, I’m growing probably 11 different varieties, and they all have different flavors. And that’s not even talking about clonal selections or root stalks or soils and hilltop versus lower on the hill and south-facing versus east-facing versus north and so on. There are so many different qualities that exist in grapes. When you do blend them, it really makes them pop.

Q. Where do you think demand for wine is headed?
I think we’ve outpriced ourselves, in some ways, from getting the Gen Zs and the next generation to see wine as being approachable. I just recently woke up to the fact that even my own tasting fees were too high for the Paso Robles region. When I started, there were 26 wineries in Paso, and wine tasting was $5 or free. I raised my prices to $20 and $30 and $40. We all did that. I think I was wrong, and it’s time to re-think it.
We all rode a wave of thinking we needed to be more and more exclusive. Maybe we need to be more and more inclusive instead. I believe we are at a fork in the road with tasting fees. At Linne Calodo, we’ve lowered ours back down to $20. If we want to win over the younger generation, we have to make it easier for them to get in the door and fall in love with great wine.

Q. Today, the Paso Robles region is home to more than 40,000 vineyard acres and 200-plus wineries. Is there any doubt anymore that it’s a world-class viticultural area?
No, it is a world-class region. It’s just still growing. We’re still learning exactly what the best grapes and training methods are. It’s suffering all the same challenges of any fast-growing region. But there is a fine group of us trying to figure out better, more sustainable, more ecologically friendly ways to pass this on to our future generations.

Putting Fungicides to the Test

UCCE Plant Pathologist Akif Eskalen recommends taking an integrated approach to powdery mildew management that includes fungicides, using the Gubler-Thomas Powdery Mildew Index to gauge disease risk and modifying the vineyard environment through practices such as leaf removal (all photos by V. Boyd.)

Although unusually cool, wet weather kept powdery mildew at bay during the early part of this season, more moderate weather in late spring created a near-ideal environment for the fungus. This allowed UCCE Plant Pathologist Akif Eskalen to put 65 fungicides, alone or as part of season-long programs, to the test under tough powdery mildew conditions at a UC Davis vineyard.

But Eskalen viewed fungicides as just part of an integrated approach that should also include using the Gubler-Thomas Powdery Mildew Index to gauge disease risk and modifying the vineyard environment through practices such as leaf removal. He also encouraged growers and PCAs to do their homework and keep an open mind.
Pete Sweeney, a PCA for Grow West in Geyserville, Calif., does just that. Each year, he said he studies the powdery mildew trial results, first when Doug Gubler conducted them and now Gubler’s successor, Eskalen.

“I really like what those guys do,” Sweeney said.

Eskalen said conducting fungicide trials annually is important as new products are introduced to the market. Having up-to-date results also helps growers.

“If you‘re just staying with what you used 10 years or 20 years ago, you’re not keeping up; you’re behind the game,” he said.

Annual Powdery Mildew Trials Continue
Eskalen took over the program in 2018, replacing Gubler who had conducted fungicide efficacy trials for about three decades.

This year’s powdery mildew trial was conducted in a 12-year-old vineyard with chenin blanc, a susceptible variety, on the UC Davis south campus. Trial entries included synthetic, organic and biological fungicides. The crew used a backpack sprayer to apply materials on frequencies ranging from 7- to 21-day intervals.

Each treatment was replicated five times, after which 25 fruit clusters were evaluated for disease severity in late July.

In this year’s trials, the organic and biological products did not perform as well statistically as synthetic compounds. But Eskalen said it was important for growers and PCAs to incorporate more non-traditional products into programs to reduce the risk of fungicide resistance from developing.

Resistance management involves rotating effective modes of action based on Fungicide Resistance Action Committee (FRAC) codes. Applying the same materials repeatedly without rotating allows for resistance development. Those pathogens not controlled by the material reproduce, eventually outnumbering susceptible organisms.

Already, powdery mildew has confirmed resistance to the strobilurin group of fungicides, also known as QoIs.

Eskalen also pointed to the state’s “Sustainable Pest Management: A Roadmap for California” released earlier this year as a reason why he included softer materials. The program from the California Department of Pesticide Registration seeks to identify what it considers “priority pesticides” for replacement or eventual elimination by 2050. The state defines priority pesticides as high-risk products, active ingredients or groups of related products considered hazardous and that pose “potentially severe or widespread adverse impacts.”

Sweeney said he has noticed the inclusion of more organic and biological compounds in the trials over the years. He also has had discussions with Eskalen about the products’ efficacy.
“If you actually talk to [Eskalen], which I have done several times, conventional products work great,” he said. “Organic products don’t come out better if you get into it and actually read the research.”

Sweeney said he also likes to take a season-long program approach to powdery mildew management, rotating products with different FRAC codes. His goal is to develop plans for his growers that have the least risk of powdery mildew development.

The Disease Triangle
Powdery mildew caused by Erysiphe necator is a polycyclic disease with multiple generations during the growing season. As such, growers may have to spray weekly or biweekly under ideal conditions to keep the disease at bay. The actual interval depends on the fungicide, weather conditions and label recommendations.

For any disease to develop, it needs a suitable host, a favorable environment and a viable pathogen.

Ideal conditions for powdery mildew in grapes include prolonged leaf moisture and temperatures between 70 and 85 degrees F. Leaf wetness and suitable temperature are the key, and rainy weather is not conducive to disease development, Eskalen said.

Cooler weather in 2023 delayed bud break and the beginning of fungicide applications by a few weeks compared to 2022. But as the weather began to warm this spring, powdery mildew took off.

“This year, in 2023, we had the perfect conditions for disease pressure,” Eskalen said. In the untreated controls in his trial, they saw 100% disease incidence, whereas in some other years, disease incidence was only 40%.

This year in Akif Eskalen’s powdery mildew trials, grape clusters in the untreated controls had 100% disease incidence.

And it’s not just ambient air temperatures but also conditions within the grapevine canopy that influence disease development.

Once temperatures move into the 90s, Eskalen said powdery mildew reproduction slows and will stop once the mercury tops 95 degrees F.

The environment within a vineyard also contributes, he said. This year’s near-record rainfall promoted tall weeds in many blocks, reducing airflow, increasing humidity and enhancing powdery mildew conditions.

In addition, variety susceptibility plays a role, with carignane, Thompson seedless, ruby seedless, cardinal, chardonnay, cabernet sauvignon and chenin blanc being some of the most susceptible.

Sweeney described this year’s powdery mildew season in the North Coast where he works as returning to normal, noting the past two years have been very light.

George Zhuang, a UCCE viticulture farm advisor for Fresno County, said table grape, winegrape and raisin grape growers in his area this season experienced more severe powdery mildew pressure than in the northern San Joaquin Valley or North Coast. He blamed it partly on increased precipitation, which promoted larger canopies that increased in-vineyard humidity and created near-ideal disease conditions.

UCCE Plant Pathologist Akif Eskalen shows a grape cluster from one of his treatments and discusses the results of his powdery mildew trials with field day attendees

The late bud break also caught some growers by surprise, Zhuang said.

“I think a lot of growers still use the calendar for spray programs and to schedule their sprays,” he said. “When we started the season, it was unusually cold, and it slowed canopy growth and slowed pathogen development.”

Typically, growers in his area begin fungicide applications about mid-April shortly after bud break. This year, they started in late April or early May, and even then powdery mildew pressure was low. In early June, temperatures warmed, and the pathogen took off.

“There was a huge explosion of powdery mildew pressure at the beginning of June, and it kind of surprised everybody in terms of how to time their spray intervals,” Zhuang said.
He pointed to the importance of the Gubler-Thomas Powdery Mildew Risk Index when timing fungicide applications.

Don’t Guess, Use the Index
Developed by Gubler and colleague Carla Thomas, the index draws data from weather stations and canopy leaf wetness sensors to determine the risk of powdery mildew developing. The model then calculates a daily risk index ranging from 0 to 100.

A reading of more than 60, for example, indicates a high risk. Growers and PCAS should shorten spray intervals to 14 days or the label minimum for chemical fungicides or seven days for sulfur, according to UC IPM guidelines. A reading of 0 to 30, on the other hand, means a low risk.

Chemical fungicide intervals may be stretched to 21 days or the label maximum, while sulfur may be used at 14- to 21-day intervals.

Eskalen said the index helps growers and PCAs make more informed decisions about fungicide applications and spray intervals.

“If we know about the conditions, we don’t have to spray based on the calendar,” he said. “That’s the risk index. If the risk is low, you don’t have to apply fungicides on a weekly basis. If the risk is high, you have to apply.”

Nearly 30 years after it was developed, Zhuang said, the index remains relevant, especially during a season like 2023.

“It’s still very important to track the powdery mildew index,” he said. “If you look at the powdery mildew index, in Fresno, we have eight weather stations across the county. You can see a very clear line that in May, the disease pressure was relatively low. But if you look after Memorial Day, everything just skyrocketed to the top of almost 100 for the entire month [of June].”

To view the results from this year’s powdery mildew trials as well as from several previous years, visit ucanr.edu/sites/eskalenlab/Fruit_Crop_Fungicide_Trials/. The site also provides links to trials that involve other fungal diseases and other tree fruit crops.

Winery Feature: Torch Cellars

Mark Welch, co-owner and winemaker at Torch Cellars, has worked in wineries across the world to perfect his own wines (all photos courtesy M. Welch.)

Torch Cellars co-founder Mark Welch had worked in multiple vineyards across the globe all his career before finally opening his own with longtime friend Greg Jelstrom. A dream come true, Welch and Jelstrom made it their mission to “craft elegant, limited-production wines that will delight the most discriminating wine enthusiast.”

Welch, who is also a certified PCA, worked his way up through the wine industry in all facets, from the field to the winery to teaching, and finally back to the winery. By the early 2010s, Welch and Jelstrom were making wine by hand as a side project and bottling their first Zinfandels. Jelstrom, like Welch, came to enjoy winemaking, and the two became business partners to form Torch Cellars.

Torch Cellars is located in western Paso Robles within San Luis Obispo County and produces from grapes grown in vineyards in the Willow Creek, El Pomar and Templeton Gap regions. Location, which includes factors like soil type, weather and aesthetic, is everything to Welch for a winery, and it played into the search for Torch’s home on the Central Coast.

Welch sat down with Grape & Wine to share his experiences working across the industry up to Torch’s inception and beyond.

From left to right, Tempranillo, Rosé and Cabernet Sauvignon options from Torch Cellars. Welch said his grandmother, an artist, created the logo he’d eventually use for Torch, which takes inspiration from the Mayan sun.

Q. How did you get your start?
I’m from Visalia originally. I went to Cal Poly [San Luis Obispo] for crop science. Two years into my agronomy class, I had Viticulture 1 and Viticulture 2. I enrolled in those. At this time, Cal Poly did not have a wine and viticulture program so a few professors with vision created a “Wine Marketing Certificate Program” in the early 1990s through the university’s extended education teaching program, which I participated and graduated. It was the beginning of what Cal Poly has now in the wine and viticulture program.

At that time as a student, I worked and was enrolled at the university yearlong. Professor Paul Fountain oversaw the teaching vineyard. Paul asked me, “I need someone to run the vineyard (Trestle Vineyard) for the summer.” I volunteered, so that’s how I got started.
The winery that was processing those grapes for Cal Poly was Wild Horse Winery and owner Ken Volk, very famous winemaker. I wanted to learn more about the winemaking process. Fast forward, after I graduated Cal Poly, I ended up going to work for Wild Horse in Templeton, Calif. I spent three years learning the wine business. At this same time, I was introduced to the music business and managed, marketed and toured with musicians for the next six years. That was fun and very educating; however, I decided to follow my passion and get back into the wine business. I went back to Cal Poly and enrolled in the master’s program for plant protection science.

Welch typically ages his wines 18 to 33 months in either French Oak barrels or a combination of French Oak and American barrels.

After graduating, Cal Poly Crop Science Department offered me a position to lecture classes and manage the vineyard along with all the permanent tree crops That’s where I met Dr. Keith Patterson, a very famous viticulturist. Keith took me under his wing… and I ended up teaching there for the next 10 years as a lecturer.

At that time, we developed the wine and viticulture program at Cal Poly. We were the first ones to develop it. I was on the ground floor.

In 2012, we had a department head change… I decided to retire and move on. Following my interest to travel and work abroad, I ended up doing grape harvest in Switzerland along Lec léman (Lake Geneva), and subsequently accepted a cellar hand position in New Zealand for the next three seasons working for Constellation Brands. After moving back to San Luis Obispo, I went to work for Midnight Cellars in Paso Robles. That’s where I started the brand, Torch Cellars.

Welch and his girlfriend, Alta, pouring wine at an event.

Q. Where did the name ‘Torch’ come from?
Torch was my nickname I was given while working at Wild Horse Winery. Ken Volk named me “Torch”. We were working in the sun so much, I looked like a surfer guy. “You’re a torch,” he said, and that’s the name.

Q. To you, what makes Torch Cellars unique?
Location has everything to do with it. On the west side of Paso, the soils are very chalky (we call them calcareous), they are old seabed soils, and the weather, of course, the day and night temperature fluctuations, those have a lot to do with the flavor of the grapes, we say.

Welch takes pride in his unique style of winemaking.

At Torch Cellars… my winemaking style is a combination of various techniques. We have seven guys that make wine down here, and all of us might use the same grapes but we don’t necessarily use the same yeast, barrels and/or aging techniques. It’s like a chef, for example, like you’re making a pizza and I’m making a pizza; we all use dough, but it’s how you make it.

I think the things that stand out for anybody making wine is your label. The brand has to be the one that kind of stands out and makes it unique. You need to have a story behind it. I think it makes it a lot more interesting when people ask about it.

I went around the world where I’ve seen a lot of different winemaking techniques and I apply them to my winemaking style.

There’s not only one way to do things. That’s kind of where you stand out between you and the next guy.

Welch makes red wines in a “Bordeaux style,” using the five primary reds from France: Cabernet Sauvignon, Merlot, Cabernet Franc, Petit Verdot and Malbec.

Q. Tell me about some of those grapes and wines you produce at Torch.
I make red wines in a “Bordeaux style,” meaning I primarily use the five primary reds from France: Cabernet Sauvignon, Merlot, Cabernet Franc, Petit Verdot and Malbec.

I always liked Cab, and I always liked Syrah, and I ended up blending this Cab-Syrah-Tempranillo, and that’s kind of my flagship. That’s my reserve. It’s always been Cab, Tempranillo and Syrah.

I love Tempranillo, it is a favorite variety I use as a standalone variety and blend. Tempranillo is from Spain, and I use a combination of American and French Oak barrels, age 33 months. It’s kind of earthy, it’s got the other elements that Cab doesn’t have or Syrah. Of course, it’s the major variety out of Rioja, Spain. I produce the wine over here and kind of do it in a different style.

I typically age 18 to 33 months in 50% New French Oak. Rhône-style wines (Syrah, Grenache) use much less new Oak (33% new French Oak) and only 18- to 24-month barrel aging.

Grenache is the workhorse of the Rhône Valley [in France], so I also do a little Grenache Rosé.

There’s about a handful of us that make Chardonnay on the west side of Paso, and it’s in a Burgundian style… meaning barrel fermented, barrel aged and sur lie aging (the process of letting white and sparkling wines mature and age on top of spent yeast and other particulate matter.) Typically, no more than five to six months in barrel before bottling. In Europe, winemakers use traditional winemaking techniques centuries old handed down by generation where in New Zealand) we use the same concepts but more mechanized and larger quantities.

Q. What’s the tasting experience like at Torch?
Everything is in the wine cellar itself, which is kind of unique. You have to have an appointment, we come in, we do the tastings, and you’re in the cellar, you see the tanks, we do some barrel tastings.

Most people are just in the tasting room, they just don’t get to see the owner. They get to see everybody else. So, it’s just with me.

Q. Separate from Torch Cellars, what’s been your personal mission as a winemaker?
Travelling really opened my eyes to traditional winemaking. My main objective with that was to just learn as much as I could and try to bring as much of that knowledge back here and try to train people.

I don’t know if I really have a mission; I just know I want to try and make the best wine I can, and I like being a PCA.

Q. Does being a PCA help when being a winemaker?
Six months out of the year I work in the wine side and the other six months I work as an independent pest control adviser (viticulture consultant). It does help me. I get questions on both sides all the time.

I’m trying to help growers be efficient. I get called all the time. It’s been a learning process.

Q. What does sustainability mean to you?
There’s a pest side, soil side, water side and people side. So, all those things taken into consideration, when we farm, sustainability is using the least of all your inputs to create a product.

I tell everybody, you’ve got to farm the soil, not necessarily just the plant because it is what’s in the soil that translates into the wine.



Defend Against Cybercrime

Ransomware and business email compromise usually happen because people click on a malicious link or PDF file (photo by C. Merlo.)

In the world of cybersecurity, they’re called “bad actors,” and they’re not just attacking corporate giants, retail chains and school systems. They’re targeting ag-related businesses too.

Criminal hackers are looking to breach your network, steal your data and compromise your operations. They can hold you hostage, denying you access to your own files unless you pay a hefty ransom. It’s not a question of if but when a cybercrime will occur, experts warn.
“It doesn’t matter what the business is or its size, the threats are very real,” said Doug Davidson, director of technology for GBQ, which Forbes lists as one of America’s Best Tax and Accounting Firms. “Today, 25% of all crime is cyber-related.”

Is your farm or winery vulnerable? If your business uses email or smartphones, it is. If your employees handle payroll, inventory, shipments and customer transactions online, it is. If your wine club conducts business via the internet, you’re at risk. In fact, anything attached to the internet is vulnerable to a cyberattack.

The primary motivation for attacks continues to be overwhelmingly financially driven at 95% of breaches, reported Verizon in its widely read 2023 Data Breach Investigations Report. It also noted the most common form of attack is ransomware, followed by business email compromise (BEC).

“Ransomware continues to be a major threat for organizations of all sizes and industries,” said Verizon.

The three primary ways in which attackers access an organization are stolen credentials, phishing and exploitation of vulnerabilities, the report added.

Threat Risks
As vineyards and wineries increase their use of technology, they must be aware of the security controls they have in place, said Melissa DeDonder, senior manager and director of external IT consulting for Pinion, a national food and ag consulting and accounting firm.
As examples, she pointed to chemical applications in the field, temperature settings during fermentation, humidity in warehouses, all increasingly controlled by automation. Further, there’s third-party risk, where processes such as sales orders and distribution are handled through digital avenues. A customer relationship management system, with customer names, addresses, phone numbers and credit card information, is also vulnerable.

“Can your system be broken into?” DeDonder asked. “What are the risks or breaches that can happen there? How are you securing that data?”

Layers of Prevention
There are several layers of cybersecurity, but the most basic prevention starts with recommendations from the Cybersecurity and Infrastructure Security Agency, the nation’s cyber defense agency and national coordinator for critical infrastructure security.
“Using strong passwords, updating your software, thinking before you click on suspicious links and turning on multi-factor authentication are the basics of what we call ‘cyber hygiene’ and will drastically improve your online safety,” CISA said. “These cybersecurity basics apply to both individuals and organizations.”

Beyond that, business owners should know what software, hardware and important data they have. That includes computers, printers, routers, security cameras and smartphones.
“We find that most organizations don’t know what they have or where it is,” said GBQ’s Davidson. “If you don’t know what you have, you can’t protect it.”

Another cyber defense is to back up data regularly, FBI agent Brad Swenson told attendees during a “Cybersecurity 101” seminar at World Ag Expo in Tulare, Calif. last February.
“Keep three copies of your data,” Swenson said. “Two of them onsite should be on two different computers, so if one crashes, you still have another. One copy should be out in the cloud or offsite. You can put it on a hard drive and put it in a safety deposit box at the bank.”

“My No. 1 cyber protection advice is to educate your employees,” says Pinion’s Melissa DeDonder (photo courtesy Pinion.)

Swenson also urged people to be careful about what they post online. Bad actors “use that information against you,” he said. “They do their research, figure out who you are, what makes you tick, then use it against you.”

Businesses should also fight cybercrime by adopting a security framework, Davidson said. He likens that to a playbook of controls put in place to identify what you have and what needs to be done to protect it.

One available framework comes from the National Institute of Standards and Technology (NIST). This government agency has developed the Cybersecurity Framework to enhance the security and resilience of the nation’s critical infrastructure. The framework integrates a set of industry standards and best practices to help organizations manage cybersecurity risks. It’s free and accessible at nist.gov/cyberframework.The

Human Element
Unfortunately, businesses’ biggest cyber threat often lies close to home. Verizon’s 2023 report found that 74% of all breaches include “the human element,” with people being involved either through error, privilege misuse, use of stolen credentials or social engineering.

For many businesses, that weak link is employees, especially those who unknowingly click on a link or open a PDF file that contains malware, or malicious software, which allows hackers in.

IT security expert Doug Davidson says 25% of all crime today is cyber-related (photo courtesy GBQ.)

“My No. 1 protection advice is always to educate your employees,” said Pinion’s DeDonder. “Ransomware and BEC happen because employees, executives or owners click on something.”

Cybersecurity training teaches people what to watch out for, whether it’s a malicious email link, PDF file or website. And once-a-year training isn’t enough, added DeDonder.
“It’s got to be constant and repetitive.”

Among other cyber-hygiene practices DeDonder advocates are patching, or updating, your system and backing up critical data you and your business can’t afford to lose. Then test your online security controls that are in place.

“And make sure you have enough of a technology budget to protect your business,” she said.

Reporting Cybercrime
If your system has been compromised, you should contact the FBI, according to Swenson. He advised victims to start with the FBI’s Internet Crime Complaint Center at www.iC3.gov. The site offers a complaint form that, once filled out, will be routed to the appropriate FBI field office so the agency can start taking action.

If a cybercrime involves a financial theft, “the quicker you can notify us, the quicker we can take action to stop that money movement,” Swenson said. “If you let us know within 72 hours of a fraudulent wire transfer, we have mechanisms in place to halt it. In the instances I’ve seen, the money gets returned.”

While Davidson recommends anyone who’s had a cybercrime event to report it to the FBI, he believes the first person you should call is your attorney.

“An attorney can help do some of the investigative work under privilege,” he said. “Then call your insurance carrier if you have cyber liability insurance.”

Bottom line: Be suspicious. Be careful what you download and what you share. Make sure your business has controls in place to detect, respond to and recover from a cyber threat or actual event. Don’t let bad actors catch you unprepared.

Cybersecurity Terms to Know

Hacking: Attempts to intentionally access or harm information assets without authorization by circumventing or thwarting logical security mechanisms.

Ransomware: A type of malicious software that threatens a victim by destroying or blocking access to critical data or systems until a ransom is paid.

Business email compromise: A type of cybercrime where the scammer uses email to trick someone into sending money or divulging confidential company information.

Spoofing: When someone disguises an email address, sender name, phone number or website URL, often just by changing one letter, symbol or number, to convince you that you are interacting with a trusted source.

Phishing: A targeted attempt to obtain sensitive data by duping victims into voluntarily giving up account information and credentials.

Data Incident: A security event that compromises the integrity, confidentiality or availability of an information asset.

Data Breach: An incident that results in the confirmed disclosure (not just potential exposure) of data to an unauthorized party.

Malware: Any malicious software, script or code run on a device that alters its state or function without the owner’s informed consent.

Sources: Verizon’s 2023 Data Breach Investigations Report; FBI.gov; Microsoft.com

FBI’s Cyber Safety Tips

The FBI is the lead federal agency for investigating cyberattacks and intrusions. Here are some tips the FBI offers to protect yourself from cybercriminals:

Keep systems and software up to date and install a strong, reputable anti-virus program.
Be careful when connecting to a public Wi-Fi network and do not conduct any sensitive transactions, including purchases, when on a public network.

Create a strong and unique passphrase for each online account and change those passphrases regularly.

Set up multi-factor authentication on all accounts that allow it.

Examine the email address in all correspondence and scrutinize website URLs before responding to a message or visiting a site.

Don’t click on anything in unsolicited emails or text messages.

Be cautious about the information you share in online profiles and social media accounts. Sharing things like pet names, schools and family members can give scammers the hints they need to guess your passwords or the answers to your account security questions.
Don’t send payments to unknown people or organizations seeking monetary support and urging immediate action.


Even sophisticated field equipment should have cybersecurity controls in place, experts say (photo by C. Merlo.)

‘Touch-Free’ Vineyard Proved Concept

Garrett Van Brocklin, a sales technician for Clemens Vineyard Equipment Inc. in Woodland, Calif., uses a Clemens Shoot Thinner for canopy management on a high wire vineyard at the UC Davis, Oakville Station in Napa County in 2021 (all photos courtesy UC Davis.)

Prompted by labor availability and ever-increasing labor costs, winegrape growers have increasingly turned to mechanization, first with harvest and then with other cultural practices.

The move didn’t come overnight and has been more of an evolution, said S. Kaan Kurtural, founder of Kurtural Vineyard Consulting in Davis, Calif. In addition, a fully mechanized production system isn’t for every grower, and they must weigh their production practices before making the jump.

But Kurtural has proven it can be done, whether growers are planting a new vineyard or wanting to convert over an older one.

For more than 20 years, he has studied mechanized winegrape production first at California State University, Fresno, and then at UC Davis, until earlier this year. One of the most recent projects he led was establishing a “touch-free” experimental winegrape vineyard at the UC Davis Oakville Station.

“15 years ago, there wasn’t a lot of economic necessity to do mechanized practices,” Kurtural said. “However, grape prices have not changed in the last 25 years. Now it’s become a necessity, and there’s been a change in the ways vineyards are planted and farmed.”

Controlling labor costs has become a focus as state minimum wages increase annually. That’s because labor tied to pruning and harvesting account for more than 80% of overall vineyard labor costs, according to research conducted by Kurtural and several colleagues.
George Zhuang, UCCE viticulture advisor in Fresno County, conducted four studies in 2019 that estimated the costs and returns of establishing and producing winegrapes in the southern San Joaquin Valley. The research, which looked at nearly complete mechanization, involved four varieties: cabernet sauvignon, chardonnay, rubired and colombard.
Based on the studies, fully implemented mechanization reduced production costs from $3,000 to $2,500 per acre, or 17% less.

Because the studies were completed four years ago, Zhuang said he couldn’t help but expect the savings to be even more today with the state’s annual increase in minimum wage.

“If you still use my numbers, the savings have jumped from $500 to at least $700,” he said.

Aiding the transition are the growing number of U.S. equipment manufacturers that have developed machines to box prune vines in one pass, Kurtural said. Many European machines, on the other hand, are designed more for the VSP (vertical shoot-positioning) trellis system and only prune on one plain.

Trellising is Key
Choosing the proper trellising that provides 360-degree machine access without cross arms or wires getting in the way is key to making full mechanization successful, Kurtural said.
Other factors to consider include topography, cultivars, rootstocks, vine and row spacing, irrigation systems, climate and yield potential. Cultivars that can be trained to have straight trunks and lateral cordons lend themselves to mechanized management. In addition, those with strong basal bud fruitfulness, such as chardonnay and cabernet, are better suited to mechanized management than varieties like Thompson seedless with lower basal bud fruitfulness.

In several trials, the single high wire trellis system performed the best, reducing labor costs by more than 90% and increasing fruit yields without reducing quality. Known by other names, including high-cordon machine pruned, the system involves training bilateral cordons on a single wire about 60 to 72 inches off the vineyard floor. Canes are allowed to flow over the sides to create a kind of parasol over the fruiting zone. The leaves don’t totally block the sun, instead acting like a sun screen to filter rays that hit the fruit.
The single-wire system isn’t far removed from the California sprawl, where bilateral cordons are topped by a single catch-wire, and canes are allowed to sprawl over the sides to create a canopy covering the fruiting zone. Where the single-wire system differs is it lacks extraneous wires that may interfere with mechanical pruning blades, saws or sickles.
The single-wire system also elevates fruit higher off the vineyard floor, minimizing damage from spring frosts that are colder closer to the ground. Recent UC research led by Kurtural also has found the system protects fruit from heat waves or increasing temperatures by keeping it farther away from heat radiating from the vineyard floor.

The VSP system, on the other hand, uses a fruiting wire about 36 to 40 inches from the ground. Three to five additional movable wires allow for shoot training. The fruit is exposed to the sun, making it prone to sunburn. The lower fruiting wire also makes buds and new leaves more susceptible to spring frosts.

While the California sprawl system works for mechanization, cross arms with two catch wires can cause big problems for mechanical pruning or shoot thinning.

In addition, the single-wire system typically helps balance canopy size with fruit load without affecting grape quality. In fact, Kurtural said, the new systems actually enhance desirable chemical components such as anthocyanins within the fruit.

“We initially started work to see if [full mechanization] would be economically profitable for the grower,” he said. “Once we established that, we noticed that the quality was much higher at the farm gate. In the end, the wine was preferred by taste panels as well.”

Mechanical Pruning
Along with harvest, dormant pruning is one of the most labor-intensive and costly cultural practices tied to winegrape production, according to Kurtural’s research.

Over the years, he and his colleagues have found that mechanized box pruning, where bearing spurs are pruned from the top, bottom and sides, mostly closely resembles hand pruning. The initial prepruning pass leaves a box with dimensions ranging from about 4 to 6 inches wide and about 4 inches tall.

Because mechanical pruning is not selective, follow-up mechanical shoot thinning after bud break and the danger of frost has passed helps achieve the desired shoot density.

Making the Switch
Zhuang, who cooperated with Kurtural in some of his previous trials, said nearly all new vineyards being planted in the south San Joaquin Valley are on single high-wire trellises.
“It’s very obvious right now based on my observations that all of the new plantings of winegrapes are on single wire or high quads shooting for 100% mechanical pruning,” Zhuang said.

Because yield is the top goal of south San Joaquin Valley producers, he said shoot thinning and leaf removal aren’t that popular.

Payton Hoover, a parts manager with Vmech, of Fresno, drives a tractor that pulls a Vmech Chariot with dual precision pruners for pruning on high wire vineyards at the UC Davis Oakville Station in Napa County in 2021. Westside Equipment acquired Vmech in June 2023.

Zhuang was part of research with Kurtural in 2019 that examined the feasibility of converting a hand-pruned San Joaquin Valley vineyard to mechanization. The 20-year-old head-trained merlot vineyard was planted on traditional trellising that involved two eight-node canes laid on a catch wire in opposite directions and two eight-node canes attached to a 66-inch-high catch wire. Although the system could be mechanically harvested, it didn’t lend itself to mechanical dormant pruning or shoot removal.

As part of the trial in the Madera vineyard, they converted 8 acres of vines to a cordon-trained spur-pruned California sprawl system or a bilateral cordon-trained mechanically box-pruned single high wire system. Of the two, the single high wire proved more successful for mechanical pruning in the San Joaquin Valley, where more than half the state’s winegrapes are grown.

Retraining the vines also resulted in yields and fruit quality as good or better than from hand-pruned vines. Once the project was completed, the vineyard owner converted the remaining 45 acres of vines to the single high-wire system.

But Zhuang said there is a caveat when converting vines to a new trellis system.
“We see a lot of those old vineyards in the south San Joaquin Valley have a lot of trunk disease, so there’s a lot of dead arms,” he said. “Typically, we don’t recommend growers convert those vines because diseases like Botryosphaeria and Eutypa will come back and impact your new vines.”

But if the vineyard is relatively healthy without a lot of dead arms, Zhuang said it would be a good candidate for conversion.