Category: Archived Articles

Maximizing Profitability Amidst Industry Challenges

By: Roberto Iturralde, Agronomic Service Representative, Syngenta

As harvest season approaches, wine grape growers face a unique combination of challenges—from fluctuating market dynamics to increasing labor costs and the ever-present threat of disease.

  To stay competitive in today’s market, it’s essential for growers to adopt targeted strategies that balance cost management with optimized production. Though the table grape sector has faced challenges, it has not been impacted as severely as the wine grape industry.

 Weathering Through the Wine Industry

  The current wine grape market presents significant difficulties for growers. According to the Wine Institute, California wine production in 2023 reached only 606 million gallons, one of the lowest levels on record since 2015. Additionally, the state’s 2024 harvest was the lightest in two decades, down more than 25% from the previous year, according to the California Department of Food and Agriculture.

  Compounding these issues, wine grape supply continues to overwhelm demand, lowering the price of wine grape varieties. The same California Department of Food and Agriculture report found that the average price for all grape varieties decreased to $992.51 in 2024, a 4.5% drop from 2023.

  The ongoing supply-demand imbalance in the wine grape industry is forcing growers to make difficult decisions, including reducing vineyard acreage. In a recent interview with Ag Alert, Jeff Bitter, president of Allied Grape Growers, emphasized the continued oversupply and urged for the removal of 50,000 acres in 2025. This follows an estimated 37,500 acres that have already been pulled between the 2023 and 2024 harvests. Bitter hopes these measures will help stabilize the market. 

  As many contracts between growers and winemakers go unrenewed and the return on investment is increasingly uncertain, growers must carefully consider every input cost to maximize their bottom line this harvest.

  To navigate these obstacles, diversification is key. While older vineyards are dropping acreage at higher rates to mitigate supply challenges, younger vineyards have diversified their portfolios by switching wine grape varieties to meet demand needs and stay in business. As harvest season approaches, it may be time for growers to reevaluate variety types to improve the likelihood of their crops being purchased in the future.

  Meticulous vineyard planning will also be vital. Optimizing irrigation, fertilization and canopy management can help reduce input costs while maintaining quality, making grapes more attractive to potential buyers. Balancing these decisions with the realities of market conditions is essential for long-term success.

Optimizing Labor and Equipment for Cost-Efficient Harvesting

  Labor represents one of the highest costs for wine grape growers, especially during harvest. Not to mention the California state minimum wage has more than doubled in the last 12 years – from $8 in 2013 to $16.50 in 2025 – while the price of grapes is on a decline. Thus, efficiently managing labor is crucial, and when paired with the right equipment, growers can significantly reduce expenses while also maintaining productivity.

  One of the most effective ways to manage labor costs is to minimize the number of tasks requiring manual intervention during harvesting. For instance, reducing the number of sprays can cut down on labor needs. By using high-performing solutions with extended control periods, growers can reduce the frequency of applications, lowering both labor and product costs over time.

  Another approach is to plan operations carefully to ensure that labor is allocated efficiently. Scheduling tasks like pruning, thinning and harvesting during optimal conditions can help avoid costly delays and overtime expenses.

  In addition to optimizing labor for cost efficiency, many growers look to machines to fill the gaps when workers are few and far between and at higher costs. The long-held belief that hand-harvested grapes are superior has become increasingly abandoned, as upwards of 80% of California’s wine grapes are now machine-picked. Growers can also choose to alternate between hand harvesting and mechanical harvesters to give vines a break from the rough handling of the machinery every couple of years.

  While the upfront cost of mechanical equipment may be significant, the long-term savings in labor costs can make it a worthwhile investment. Mechanical harvesters can handle large acreage in a fraction of the time that it would take a manual workforce, allowing growers to be less reliant on seasonal labor.

  Additionally, using modern pruning and spraying equipment can speed up operations and improve treatment consistency to help maximize the return on investment. Mechanical leaf and sucker removal can also be done before harvest to help prevent disease, especially in humid environments, and to unmask bunches for picking, which in turn reduces harvesting time. Properly functioning machinery not only saves time but also minimizes the risk of crop damage, which can affect yields and quality. Growers who utilize machinery should take caution to maintain and calibrate equipment regularly to ensure peak performance during harvest.

Early Detection of Diseases

  A profitable harvest season begins with healthy vines, and disease management is paramount to achieving optimal yields. Amidst industry challenges and rising labor costs, every vineyard management decision is critical, including how growers monitor and prevent disease outbreaks.

  Common diseases like powdery mildew can wreak havoc on vineyards if not addressed promptly. It’s essential to identify potential disease outbreaks early by closely monitoring crop development throughout the season. Initial symptoms of powdery mildew may appear on leaves as chlorotic spots on the upper leaf surface. As spores are produced and spread to the lower leaf surface, the infected areas take on a white, powdery or dusty appearance, which may eventually overtake the entire grape surface.

  Regular scouting for disease symptoms can help growers take timely action before the infection escalates. Using advanced technologies, such as remote monitoring solutions and digital imaging, can further improve the accuracy of disease detection.

Proactive Disease Management

  As bud break occurs, sulfur dusting can provide an economical protective barrier on grape leaves and stems, preventing fungal diseases like powdery mildew from infecting the plant. Once there is an active infection, growers will typically transition from sulfur dusting to a more powerful chemical that can provide extended control. As vines mature into the bloom stage through bunch closure and veraison, a premium spray may be necessary for effective disease management to maximize yield potential at harvest.

  Incorporating an effective fungicide into a comprehensive spray program can significantly aid in disease protection and prevention. A FRAC 3/7 fungicide like Aprovia® Top delivers preventive activity and extended broad-spectrum control of powdery mildew and other common grape diseases, which reduces the need for frequent applications and lowers overall input costs.

  A versatile tank-mix option can serve as a valuable resistance management tool and can also be effective in rotation programs with other modes of action. Consider a fungicide that also offers plant health benefits, which can lead to higher yield potential and quality fruit at harvest. Combining fungicide use with cultural practices, such as improved air circulation through canopy management, can further reduce disease pressure.

  Balancing disease prevention with cost management is an ongoing challenge for growers. By investing in high-quality products that offer long-term efficacy, growers can reduce the number of inputs required over the season, while maximizing ROI and yield potential.

A Look into the Future

  Preparing for the harvest season requires wine grape growers to adopt a multifaceted approach that addresses economic, operational and agronomic challenges. By understanding market dynamics and adapting vineyard management practices accordingly, growers can better position themselves for success in an uncertain industry. Efficient labor and equipment utilization further enhance operational effectiveness, while proactive crop monitoring and disease prevention can maximize yield potential and improve fruit quality.

  In these challenging times, strategic planning and innovation are vital for continued success in the wine grape industry. By implementing these tips, growers will be better equipped to navigate through future complexities and uncertain times.

  For more information about Aprovia Top fungicide, visit https://www.syngenta-us.com/fungicides/aprovia-top

Author Biography:

  Roberto Iturralde is an Agronomic Service Representative with Syngenta in Fresno, CA. He is also a Certified Crop Advisor and Pest Control Advisor, specializing in permanent crops including grapes, tree nuts, citrus and more. He can be reached at roberto.iturralde@syngenta.com.

Legalese:

  Syngenta hereby disclaims any liability for third-party websites referenced herein.

  All photos are the property of Syngenta or are used with permission.

  © 2025 Syngenta. Important: Always read and follow label instructions. Some products may not be registered for sale or use in all states or counties. Please check with your local extension service to ensure registration status. Aprovia® and the Syngenta logo are trademarks of a Syngenta Group Company. All other trademarks are the property of their respective third-party owners.

Hard to Believe but We’re Almost at Harvest Already Again!

By: Thomas J. Payette, Winemaking Consultant

Preparing for harvest is critical and really preparing for harvest happens all during the year if you think about it.  It’s not a one day process just before the first load of fruit arrives on the crush pad.  Or I hope not.  We will go over the planning process of how to be most prepared and confident when the fruit of the harvest starts to arrive.  Part of the plan may include taking a vacation so read on!

Obtain an Erasable Wall Calendar:  This will be the most useful tool for your planning from bottling, to fixing equipment and ordering yeast/chemicals etc.  I prefer a large erasable calendar so one can plan out 4 to 6 months at a minimum.  Have cellar worker use this for any projected time off also.  It is a great communications tool!  This calendar is your overall master plan.

Note Taking During Harvest:  This is the first step and the key step for subsequent success in future harvest to come.  Make notes of any production pitfalls, machinery issues, fruit handling upgrade wishes etc.  Keep visiting this list and make sure to plug budgetary items at the appropriate time.  I like to use our “daily transaction log” for this note taking detail.

Best Time to Start:  Start preparing for the harvest planning exercise by optimistically looking at the vineyard and expected fruit or juices for the harvest seven or eight months in advance.  Plan, order and negotiate any cooperage or tanks space adjustments early on to fit upcoming predicted production.

Plan Tank Capacity:  With an initial vineyard projections in hand start to forecast open tank capacity and cooperage.  Plug into this projection tanks you expect to have bottled by harvest.  Is there enough tank capacity?  Is there an overrun plan?  Would large tanker trailers be available if needed for excesses?  Think through as many options as possible.  If you calculate you need more volume capacity– get that on order and moving on its way toward your winery.  Avoid last minute crisis.

Make a Bottling Schedule:  Make sure to plan exactly what you need to bottle to integrate properly with the sales goals and to empty the amount of tank space needed.  This will need to be coordinated with the warehouse personnel and taking into consideration warehouse space.  Stick with the bottling schedule since it is integral to your projected bulk wine volume tank space requirements needs.  Speak with sales to understand their expected sales rates and understand if any varietals will be placed on special accelerating predicted sales rates.  Plan.

Visit the Machinery in the Winter Months:  Start reviewing worn out belts, replace and repack bearing that are showing wear.  Motors; bearings; gearbox; chains etc.  Order spare parts of anything that seems worn or in need of repair soon.  Create a plan.  Upgrade the machinery and adapt to making the crush process easier.  Look at pomace removal systems and explore options.  Perform these repairs and reviews while you have the time to take action.  (The same theory applies during harvest.  By this I mean to work on your bottling line during harvest!)

Review the Cellar Journal/Log:  Looking at entries in the cellar log will often jar the memories of items that needed refinement from the prior harvest prior.  This will help in the planning process of what may need attention for next harvest also.

In the Spring:  Start to count picking lugs, bins and gondolas.  Review vineyard data projections for tonnage and get a grasp on how that tonnage will be transported to the winery.  Inspect wagons and gondolas.  This review in the spring will allow enough time to make adjustments and to plan for these upcoming events.  Make plans for harvest help and contact any interns you plan to place

Early Summer:  Have a solid vineyard crop estimate submitted by each grower.  With more solid fruit estimates in hand refine your tank and vessel needs for the winery.  Start thinking about yeast, nutrients, ML and stylistic production goals.  How will these be achieved?  Start taking further action to fix and refine the machinery for the crush pad.  This is a time of year better suited for this work weather wise outdoors and allows for errors to be fixed with ample time.  Remember European crush equipment may take time to get replacement parts.

Mid Summer:  Have a review done of your chilling system.  Is it operating properly?  Will there be enough tonnage for the increased capacity?  Do you care to relocate any tanks?  Will refrigeration/glycol lines need to cut for adding additional tanks?  Will this impact your bottling schedule?

 Two months before harvest:  Place an order for yeast, enzymes, nutrients, ML cultures, tank cleaning chemicals, citric acid, ect.  Have comfortable shipping dates discussed with your supplier to avoid rush fees.

•    Start to address clutter in the winery and on the crush pad.  Contact the appropriate people to solve any situations that exist.  Having the proper elbow room at the start of crush is crucial for mobility during crush.

•    Fix and or replace any leaky transfer hoses.  Order needed gaskets; clamps etc to make sure the hoses can be repaired and assembled without leakage.

•    Order all fresh lab chemicals to get you through the entire crush season.  Date them as they arrive.  Clean house :  Out with old… in with new.

•    Develop and refine any written protocols (Lees filter press operation, tank cleaning, press cleaning, crusher cleaning etc) for upcoming harvest helpers or interns.  If interns will be from another country try to have your protocols translated or have interns do this at the end of one of the previous seasons.

•    Physically rehearse step by step the harvest crush pad process on the crush pad.  Have everyone understand the grape/must/product flow that will be anticipated for each style of wine.

•    Discuss possible two shift scenarios if you envision this may be something you are considering.  Most people are receptive to this option if they can mentally prepare.  Less success is achieved if the idea is new and forced.

Start a List of Odd Jobs:  I have often found this to be very helpful when fruit is delayed and harvest helpers are apt to just stand and wait.  Painting the outside fence, sprucing up the winery entrance or repairing picnic tables for common area can be some examples.  All wineries have project lists that are usually very long and this can help cross those off the list.   This is a great point score with owners and keeps employees busy.

  Once all the bottling is finished and some breathing room potentially exists start to work on and repair the bottling line during harvest.

Take a Vacation:  (Serious)  Once you have successfully completed the bottling and all your harvest chemicals are either in house or confirmed on their way….take a vacation and make sure your other staff take a vacation.  This is the dangling carrot that keeps us all challenged and ultimately relaxed going into a harvest.

Low Stress:  Start your harvest in a low stress relaxed environment while taking notes on future needs and improvements so each year will become smoother and smoother.  Your low stress start will allow you to handle the complexities of harvest with confidence, courage and excellent judgment.  Your winemaking will shine as a result of your planning – not the other way around.

In Short and Summary:  Start taking notes this upcoming harvest and plan your machinery maintenance very early.  Use a calendar to help keep this project moving along, bottle up all the wine projected and be ready for the expected tonnage to arrive and perhaps a few extras.  Be ready for anything!

By: Alyssa L. Ochs

Smart equipment investments are essential to running a profitable, sustainable, modern vineyard that aligns with your business goals. Some of the most affordable and versatile equipment solutions are small tow-behind implements that work well between rows of grapevines.

  Tow-behind equipment is especially beneficial for small and mid-sized vineyards with tight budgets. With the right mulchers, spreaders, mowers, deleafers, and harvesting tow behinds, you can maneuver tight spaces and rely less on manual labor to save costs and overcome worker shortage issues.

  To learn more about compact, nimble machines that aren’t unnecessarily complicated or overpriced to strain your budget, we connected with several industry leaders offering small tow-behind equipment for vineyards.

BDI MACHINERY: Time-Saving Deleafers and Optimal-Coverage Sprayers

  BDi Machinery, based in Macungie, Pennsylvania, offers a wide selection of vineyard equipment. BDi sells many types and sizes of sprayers, hedgers, leaf removers, shredders, cultivators, pruners, mowers, row mulchers, and other specialized machines.

  Paul J. Licata from BDi Machinery explained that his company focuses on growth and cultivation mechanization equipment and is the exclusive importer of OLMI Pneumatic Deleafers for vineyards in the U.S. OLMI is the pioneer, innovator, and premier brand of Pneumatic Deleafers, which encourage optimal grape development and lead to improved grape health and quality wine.

  “An OLMI deleafer does not harm grapes during any period of use, since the OLMI leaf remover does not work in contact with vegetation,” Licata said. “It allows work in any kind of vineyard and has short application times. The OLMI in pre-harvest facilitates manual harvesting with a saving of time of 30 percent, while with mechanical harvesting it eliminates moisture in the fruiting area so a greater cleanliness of the crop can be reached. Also, fungicides and other impurities in the tanks of the harvester can be reduced. Even in this phase, the deleafer does not harm the grapes.”

  Licata shared that this deleafer requires 50 PTO HP for a single diffusor head machine and 85 PTO HP for a multi-head diffusor head model machine. Maintenance and inspection after each use stage during the growing season involve checking the filter, greasing points, oil levels for the compressor and gearbox, and the fan coupling joint.

  “We provide complete post-purchase support for the startup and training of the machine use,” Licata said. “Whenever there is a need, we and our customers are in direct contact with the OLMI Italy factory for all customer needs, and we offer a one-year warranty.”

  He shared that the typical return on investment for an OLMI deleafer is 1.5 to 2.5 years, depending on the size of your vineyard operation.

  Licata also told us that BDi Machinery imports CIMA Low-Volume Atomizer Sprayers, which are the pesticide sprayers of choice for growers who want quality, clean fruit. They offer a better alternative to traditional high-volume air-blast “soaker sprayers” that don’t have consistent pressure control.

  “The CIMA Blitz Trailer Model T50 – 300 Gallon with a TC.2M2M spray head is a very common solution for our customers for single row, and TCF.2M2M spray head for multi-row,” Licata said. “The CIMA makes droplets in the 100 to 150µ range. In contrast, a high-pressure “soaker sprayer” commonly makes droplets in the 250-400µ range.”

  “Since droplets are three dimensional, when you break down a large droplet, it has many smaller droplets inside of that large droplet,” he explained. “Therefore, with a CIMA Atomizer Sprayer, you will have many more droplets available for better coverage. This type of spray method also allows you not to have to spray to a drip. Unlike typical high-pressure air blast sprayers with air speeds around 80 to 100 mph, the atomizer-style delivery system coats all surfaces of the canopy with air speeds around 170 to 200 mph, achieving better quality of coverage and yielding a cleaner crop.”

CLEMENS TECHNOLOGIES: In-Row Cultivating and Mechanical Weed Control

  Another company, Clemens Technologies, offers efficient and sustainable machine solutions that make winegrowers’ daily work in grapevine rows easier. Clemens Technologies was founded in 1952 and is based in Germany. The company launched in the early 1970s with a specialization in mechanizing all work steps in vineyards and orchards.

  Clemens’ first product line featured specialty cultivators for working the soil in steep hill conditions. From there, the company developed a steadily perfected line of soil-working equipment, especially mechanical solutions for in-row cultivation and weeding to avoid the use of herbicides. Clemens’ machines operate worldwide in all vineyard conditions, row spacings, and varieties.

  Since 1988, Clemens Technologies USA has been based in Woodland, California, offering these vineyard solutions to the U.S. wine industry. Here, Clemens provides products for under-row care, soil cultivation, canopy management, tool carriers, high-wheel tractors and crawlers, and vineyard management software.

  Owner and president Thomas Clemens explained to The Grapevine Magazine that his company specializes in in-row cultivating and mechanical weed control. Clemens’ equipment solutions are designed year-round for mechanical weed control in vineyards and orchards, especially in the spring and summer.

  “The well-known Clemens Radius under-vine-weeder undercuts the weeds and detects the vine,” Clemens said. “Is mounted to a tractor or tool carrier either in front, in the rear, or in between the axles. It is driven by tractor hydraulics, like most of the Clemens products. There are multiple versions and accessories for the Radius.”

  “For high weed situations and no-till vineyards Clemens offers a brush system, called Multiclean, which mows the weeds in between the vines,” Clemens went on to share. “Also, this unit is hydraulically-driven and has the same mounting options as the Radius.”

  In addition to these pieces of vineyard equipment, Clemens Technologies has offered a range of machines for canopy management since the early 2000s. These products include pre-pruners, hedgers, shoot-binders, and leaf-removers.

  Clemens told us that all his company’s products are low-maintenance and easy to service. If repairs are needed, parts are always available in Clemens’ Woodland, California warehouse.

  “Modern tractors are equipped with sufficient hydraulic remotes nowadays,” Clemens said. “If not, we offer joystick controls to provide a comfortable and most efficient way to control the equipment. Most of the Clemens units are available in one-sided or two-sided versions. During intensive discussions with the customer, we configure the right setup for each individual vineyard situation.”

GEARMORE: Various Attachments to Make Tractors More Productive

  Based in Chino, California, Gearmore sells reliable tractor attachments exclusively through servicing tractor dealers. For over 50 years, it has served the vineyard, farm, ranch, landscape, municipal, and construction industries. Gearmore’s primary service areas are California, Nevada, Arizona, New Mexico, Texas, Hawaii, Baja California, and Sonora, Mexico. However, it also sells products nationally and globally.

  Its selection of vineyard implements includes sprayers, vine trimmers, deleafers, pre-pruners, compost spreaders, and sulfur dusters. Skid steer mowers, mower shredders, soil conditioners, air blast sprayers, and in-row cultivators are other products available.

Innovations in Modern Tow-Behind Equipment

  Many vineyard managers have been gradually shifting away from large, heavy, and complex machinery that damages vine rows and compacts soils. Instead, they’re looking for more manageable equipment solutions that can easily be hitched to tractors and navigate tight rows over challenging terrain. Vineyards between five and 50 acres of rows benefit tremendously from this approach.

  Vineyard managers rely on tow-behind equipment to achieve sustainability goals by reducing soil compaction and promoting long-term vine root health. Variable-rate technology, data-logging features, and GPS guidance further enhance product offerings with greater automation and precision. Lightweight, eco-friendly equipment materials like aluminum can further minimize vineyard impacts and boost soil health.

  Another industry innovation trend is multi-function, modular tow-behind platforms, which are versatile tool carriers able to accommodate multiple attachments. Vineyards can consolidate multiple tools into a single platform for spraying, cultivating, mowing, and other tasks while minimizing downtime. Some systems include digital dashboards, quick-swap interfaces, and remote diagnostics using Wi-Fi connectivity.

Choosing and Maintaining Your Tow-Behind Equipment

  Vineyard managers can avoid common maintenance and operational challenges by implementing regular maintenance plans at defined intervals and as specified by equipment manufacturers. Regularly inspect your tow-behind equipment by greasing it and checking the fluid levels and belt tension.

  “Importantly for BDi Machinery customers is the stocking of parts and support materials for all the brands we represent,” Licata from BDi said. “Anyone can sell a machine, but the service, parts, and support is where the rubber hits the road. Customers know they can always count on BDi Machinery, with also additional direct factory technical support should that ever be needed.”

  Licata also advised that customers must understand the specific tow-behind equipment tractor requirements before making any purchase. The relevant and essential technical tractor specifications include the tractor HP, PTO HP, hydraulic flow rates at remotes, and electrical outlets for controls. It’s also necessary to assess your vineyard application criteria, such as row width, row height, trellis system, growing system, irrigation system, and soil density.

  Looking ahead, we may see future innovations involving autonomous tractors and tow-behind units guided by GPS and robotic systems. Meanwhile, self-leveling mowers and sprayers can help vineyard managers make real-time adjustments based on their terrain. Other high-tech tools to watch in the years ahead are performance tracking tools to help you monitor tow-behind equipment usage, labor needs, and maintenance schedules.

  Embracing innovations in vineyard tow-behind equipment can give winegrowers a competitive edge while maintaining an authentic, hands-on production approach. With precise, well-designed machinery that improves both vine health and worker productivity, tow-behind equipment has come a long way from its original, humble beginnings.

A Living Foundation Beneath the Vine

Cover Crop of Native Texas Wildflowers in the Texas Gulf Coast

By: Daniel Hillin and Justin Scheiner, Ph.D. – Texas A&M AgriLife Extension Service

Soil is more than just the ground beneath our boots. For grape growers, it is the living foundation of every vine, vintage, and bottle. Sometimes overlooked as just an inert medium, soil is now understood as an extremely complex and dynamic ecosystem. The concept of “soil health” has emerged as a cornerstone of modern viticulture, blending ecology, chemistry, biology, and sustainability. But what exactly is soil health, and what all does it encompass?

  The USDA Natural Resources Conservation Service (NRCS) defines soil health as “the continued capacity of soil to function as a vital living ecosystem that sustains plants, animals, and humans.” It’s a functional definition that shifts the focus from soil as a passive growing material to one that is alive and responsive. Unlike “soil quality,” which often refers to inherent characteristics like texture or fertility, soil health emphasizes the dynamic, living processes that can be improved or degraded over time.

The Biological, Chemical, and Physical Components

  At the heart of soil health is life itself. Billions of bacteria, fungi, protozoa, nematodes, and arthropods form a vibrant web underground, collectively known as the soil food web. These organisms decompose organic material, cycle nutrients, build soil structure, and suppress pathogen activity. In vineyards, a diverse and active biological community helps buffer vines against stress while simultaneously supporting nutrient uptake. For example, mycorrhizal fungi form symbiotic relationships with grapevine root systems, thus extending their access to water and certain nutrients. In Texas vineyards, especially those with minimal tillage and ground cover, growers report higher earthworm activity and microbial respiration rates—an encouraging sign of thriving biology.

  Healthy soil must also provide the chemical building blocks of plant growth. This includes essential nutrients such as nitrogen, phosphorus, potassium, magnesium, calcium, and a suite of micronutrients such as iron, zinc, and boron. Nutrient availability depends not just on how much is present, but how accessible those nutrients are to plants. Soil pH, salinity, and cation exchange capacity (CEC) all influence nutrient dynamics in the soil and ultimately the amount of nutrients available to the plant. In many Texas vineyards, high-pH calcareous soils can tie up micronutrients like iron and zinc, leading to deficiencies even when these nutrients are present in adequate quantities. Maintaining balanced fertility through soil and petiole analysis and amendments is key to supporting chemical soil health.

  The physical structure of soil influences everything from water infiltration to root growth. Soil texture (sand, silt, clay), aggregate stability, and bulk density all play a role in shaping the vines root environment. Healthy physical properties help support vigorous root systems, allow for both timely drainage and water retention, and help mitigate soils from compaction and erosion from everyday vineyard tasks.

  Click Series Gravelly Soil Under Vine in the Texas Hill Country

Soils in the Texas High Plains AVA are often deep and sandy with good drainage, while some areas in the Texoma and Hill Country AVAs tend toward heavier clay soils that can compact easily. In vineyard systems, with frequent traffic, narrow row spacing, and fixed irrigation lines are common, compaction becomes a critical concern. Growers can enhance physical soil health by minimizing mechanical disturbance, avoiding traffic on wet soils, and incorporating organic matter to improve structure.

  Often called the “gold standard” of soil health, organic matter is central to physical, chemical, and biological functioning. It improves water-holding capacity, fuels microbial life, and increases the ability of the soil to retain nutrients. In soils with naturally low organic matter, increasing soil organic matter (SOM) levels in vineyards is a process that requires a long-term investment. Practices such as compost applications, cover cropping, reduced tillage, and mulching can incrementally build organic matter content year to year. In Texas, where soil organic content is naturally low due to high temperatures and erosion risk, establishing and maintaining a cover crop and adding compost or biochar can make a significant difference.

Medlin Clay Soil Midrow in the North Texas Region

Managing Soil Health in Vineyards

  Soil health can be observed in the field and measured in the lab. Observable indicators include aggregate stability, root depth, soil smell, and biological activity (like earthworms). Lab tests might assess organic matter content, microbial respiration, bulk density, or nutrient profiles. While no single test captures all aspects of soil health, combining multiple indicators over time helps growers make informed decisions. Some vineyards are beginning to adopt composite soil health indices that synthesize biological, chemical, and physical data into one management tool.

  Soil health in vineyards is not static, it is something growers can actively build through thoughtful, region-specific management. Key practices begin with minimizing soil disturbance by reducing tillage and avoiding equipment passes when soils are wet, especially in heavy clay regions prone to compaction. Protecting the soil surface with cover crops or mulches not only guards against erosion but also supports biological activity and enhances organic matter over time. Cover crops improve soil structure by creating pore spaces, regulating soil temperature extremes, and increasing water infiltration, especially after rainfall.

  Organic matter contributes to thermal regulation in the root zone, protecting vines from temperature extremes. Texas soils, especially in the High Plains and Hill Country, often suffer from naturally

low organic content due to warm climates that accelerate decomposition. Adding compost, tilled cover crop residue, or biochar, and selecting materials with balanced carbon-to-nitrogen ratios help stimulate microbial life and lessen nutrient immobilization.

  Annual Ryegrass Utilized as a Cover Crop in the Texas High Plains Region

Proper drainage is another critical factor. In poorly draining soils, growers are encouraged to conduct percolation tests and consider pre-plant interventions like subsoiling or installing French drains. For clay-heavy soils, deep ripping before planting and inter-row cover crops can help break up compaction layers. Sandy soils, though well-drained, may struggle with nutrient leaching requiring split fertilizer applications and nematode-resistant rootstocks.

  Ultimately, managing soil health is a holistic, site-adapted process. Incorporating these strategies improves vine performance and ensures optimal vine health in the face of Texas’s highly variable climate while contributing to consistent wine quality.

Texas Terroir: Soil Diversity and Potential

  Texas’s diverse wine regions—High Plains, Hill Country, North Texas, West Texas, and the Gulf Coast—showcase a broad spectrum of soil types that shape not only how grapes grow but also how wines taste. Each region presents unique soil-driven opportunities and challenges for the vineyard management approaches and ultimately the wine expression.

  High Plains: The Texas High Plains, known for its elevation and arid climate, is dominated by well-drained sandy loam soils over a layer of caliche. These soils allow deep root penetration and efficient drainage, reducing disease pressure. However, they tend to be low in organic matter and nutrients, requiring strategic inputs such as fertilizer, cover crops, and irrigation. Wines from this region often exhibit full bodied styles with pronounced fruit character.

  Amarillo Fine Sandy Loam Soil in the Texas High Plains Region

Hill Country: Soils in the Hill Country are as varied as its landscape, everything including granite-based sandy loams, shallow limestone, and even clay-rich profiles. Wineries report that local limestone-based soils impart a distinct minerality to wines and these soils are prized for their drainage and root penetration qualities. The mix of soil types enables a wide range of grape varieties to thrive, including Tempranillo, Viognier, and Mourvèdre.

  North Texas: This region, encompassing the Texoma area, features soils with high clay content and silty loam overlays. These soils can retain water well but may require aeration and organic matter to improve structure and avoid compaction. The historical roots of grape growing in this area, especially with both hybrid and vinifera varieties, are well-suited to the regional soils and climate.

  West Texas: West Texas includes parts of the Davis Mountains and desert-influenced zones with volcanic, granitic, and calcareous soils. These high-elevation soils are often shallow and rocky but mineral-rich, offering excellent drainage and imparting complexity to wines. Managing soil structure and organic content is vital in this region, where water retention can be a challenge.

  Gulf Coast: The Gulf Coast wine region features flatter terrain with sandy, often acidic soils and high humidity. While disease pressure is higher, the well-drained sandy soils help minimize root zone saturation. Grape varieties like Blanc du Bois and Black Spanish, and the new UC Davis “Walker Varieties” known for their resistance to Pierce’s Disease, thrive in these conditions. Maintaining organic matter and cover crops is key to controlling vine vigor and maintaining soil resilience.

  This soil diversity across Texas is not just an environmental feature, it’s a functional tool that can be utilized. By understanding the foundational properties of their region’s soils, growers can make informed decisions about vineyard designs, rootstock selection, fertility management, and irrigation rates, all of which directly impact wine quality and vineyard longevity.

  Overall, soil health is not a singular trait. It is the integration of biology, chemistry, and physics, shaped by time, management, and environment. For grape growers, cultivating healthy soils is as foundational as pruning or irrigation. In Texas and beyond, managing soil as a living ecosystem is no longer a luxury, it’s a necessity for long-term vineyard sustainability. Investing in soil health means investing in the future of the vine, the vineyard, and the wine itself.

References

Helwi, P. 2020. Nitrogen Management in Vineyards. Texas A&M AgriLIfe Extension Service. HORT-EHT-143.

Lazcano, C., Decock, C. and Wilson, S.G., 2020. Defining and managing for healthy vineyard soils, intersections with the concept of terroir. Frontiers in Environmental Science, 8, p.68.

Scheiner, J., and M. Cook. 2024. Understanding Vineyard Soils. Texas A&M AgriLIfe Extension Service. HORT-PU-290.

By: Judit Monis, Ph.D., Plant Health and Vineyard Consultant

Presently there are many laboratories that provide testing services for the detection and diagnosis of plant pathogens (disease causing agents).  It can be confusing to the grower, vineyard manager, and/or nursery staff to decide which laboratory to choose.  My recommendation is to work with a plant pathologist who can provide guidelines towards the best option.  At the time, there is no accreditation that is specific for grapevine diagnostic laboratories.  Therefore, each laboratory is free to develop their own testing and sampling methodologies.   

  My expertise in grapevine disease diagnostics and my past work on developing state-of-the-art testing laboratories puts me in a position to evaluate the different choices for my clients.  The short answer is that there is no “one lab that fits all”.  In my experience, it is best to choose a lab based on the knowledge and capabilities specific to the needs of the project. 

  This article will describe the different methods used for grapevine pathogen diagnostics and discuss how they are best applied depending on needs.  In some cases, you may have to submit samples to different laboratories to test their proficiency.  However, different labs may offer different services or may be more knowledgeable in the detection of  certain bacterial, fungal, or viral infecting pathogens.  Therefore, a lab may be a better fit depending on the testing needs.

Different Testing Scenarios

  Just as there are different laboratories that offer testing services, there are different reasons for submitting samples to a testing laboratory.  Generally, I am called to a vineyard to determine the cause of a problem after the vineyard was planted.  This is not an ideal situation, as I have to “play” detective to determine if the disease originated at the nursery (i.e., plants were infected before planting) or at the vineyard (i.e., transmission occurred after planting).  Therefore, planning before planting is of upmost importance.  It is best to learn that the propagation or planting material is free of important pathogens before planting either at a vineyard or the nursery. 

  It is possible that specific symptoms of disease are present and can help decide which tests to run.  But it is also possible that infected vines will not show any symptoms at all.   Depending on these different scenarios, I am able to help devise the best sampling  strategy as well as what laboratory would be best suited for each situation.

Description of Common Laboratory Methods

Microbiological Culture:  Fungal and bacterial pathogens can be cultured and isolated in specialized (selective or semi-selective) media.  However, microorganisms often compete with each other.  For example, saprophytic (those that feed in dead material) bacteria and fungi grow much faster than pathogenic ones.  Consequently, the faster organicism’s often outcompete  the slow growing ones, making the diagnosis of certain bacterial or fungal pathogens difficult.  Here is where laboratory expertise is important to avoid a biased diagnosis.  Often times the laboratory may not be able to report the disease causal agent by using a traditional microbiological culture, but could apply sophisticated molecular methods in combination with culturing methods.

  In some cases, the identification of the fungal taxonomic family (i.e., species of the Diatripaceae or Botryosphaeriaceae family isolated from a canker) or bacterial genus (Agrobacterium species isolated from a typical gall) may be sufficient to decipher the cause of the problem.  Phytoplasmas (a special type of bacteria that lack cell walls) and viruses cannot be cultured and their identification must be carried out using molecular and serological methods.

ELISA, PCR, RT-PCR, qPCR:  ELISA is the abbreviation for “enzyme-linked immuno-sorbent assay, and consists the binding of a protein (coat protein, in the case of a virus) on a plastic test plate that was coated with specific antibodies.  A positive reaction is seen when there is a change of color in the wells of the test plate (colorimetric enzymatic reaction). ELISA detection is limited to the amount of virus present in the sample.  Therefore, it is rare for contaminations when this method is applied in the lab.  ELISA is an antibody-based test, although it is different from the rapid home tests that detect the flu and COVID 19.  PCR, is the abbreviation for polymerase chain reaction (this is a molecular based test).  The technique allows the multiplication nucleic acid from the concentration of pathogen present in the vine.

  The process is specific, and utilizes copies of small portions of the pathogen’s genome (called primers) to start the copying process. The amplification is repeated many times, with each copy making more copies, so after the completion of an appropriate number of PCR cycles, more than a billion copies of the nucleic acid is produced. For RNA viruses the detection is done using RT-PCR (RT stands for reverse transcription, a molecular way of copying the RNA to produce DNA).  PCR and RT-PCR are sensitive techniques used for the detection of grapevine pathogens.  Quantitative or Real Time PCR is a modification of PCR that can provide the relative quantitation of the pathogen present in a sample (abbreviated as qPCR and qRT-PCR).

  The sensitivity and specificity of the detection of pathogens can be influenced by the season as well as the part of the vine from which samples are collected. While ELISA is generally thought to be less sensitive than RT-PCR, ELISA has a broader spectrum of detection and can detect a range of virus variants. On the other hand, PCR is very specific, this can be an advantage but also a disadvantage. 

  If the detection is too specific, it could miss the detection of isolates of the same virus even when small changes (mutations) are present.  TaqMan, is a special type of qPCR that in addition to specific primers uses a specific probe to increase the sensitivity of the test.  Because the test is so specific, it is known to miss detection of viruses prone to being mutated in grapevine samples.  

  This is why running both ELISA and RT-PCR consecutively is recommended for the reliable detection of grapevine viruses, as each method is designed to detect different portions of a virus.   Since Grapevine red blotch virus is a DNA virus, and ELISA is not available, I recommend that PCR is performed to amplify at least two different locations of the viral genome.

Rapid Tests for the Detection of Grapevine Red Blotch & Grapevine Pinot Gris Viruses

  A single use strip test based on the recombinase polymerase amplification (RPA) assay has been developed for the detection of Grapevine red botch virus (GRBV) and Grapevine Pinot Gris virus (GPGV).  The manufacturer claims that these tests can be performed in the field. However, to obtain reliable results, the assays should be conducted by experienced technicians in a clean laboratory.  If a lay person were to attempt to run this type of assay, the assay instructions must be carefully followed. 

  The protocol includes many steps that require measuring small quantities of reagents (microliters).   Thus, it is worthwhile to have an experienced laboratory run these tests.  Laboratory personnel are used to running different protocols and are trained to keep the sample and other materials free of contamination.  Another drawback of these rapid tests is that these are only available for two grapevine viruses.  As I have noted in other articles, the symptoms caused by grapevine pathogens can confused.  For instance, a negative GRBV result, may give a false reassurance that the vines in the vineyard are healthy when they could otherwise be infected with leafroll (GLRaVs), Vitiviruses, a combination of these, and/ or bacterial or fungal pathogens.

Loop-Mediated Isothermal Amplification (LAMP)

  Like PCR, LAMP is a nucleotide amplification method that uses primers to initiate the copying process of the pathogen’s nucleic acid.  It differs however as the reaction often does not require the extraction of nucleic acid and is performed at a constant temperature (isothermal).  These LAMP assays have been developed in South Africa for the detection of GLRaV-3 and at Cornell University for the detection of GRBV.  Training of the methodology for the detection of GRBV was covered in various sessions by the Napa Valley Vineyard Technical Group. 

  The technique is  more sensitive than PCR.  Because LAMP assays are very sensitive, it is prone to contamination (i.e., yield false positives).  Like RPA, the operator will need to follow carefully a protocol that requires the measurement of very small volumes of reagents.  The technology also requires the initial investment of laboratory equipment and a clean area to perform the operations.

Next Generation or High Throughput Sequencing

  The next generation sequencing (NGS) also known as high throughput sequencing (HTS) is a powerful method that allows a laboratory to detect any organism present in a sample.

  When NGS or HTS is applied, the complete sequence of the plant genetic material and its microbiome is obtained.  Generally, during the sample preparation, the pathogens specific sequences are enriched to increase the sensitivity of the assay (for example the lab may be interested in amplifying only fungal sequences).  The data obtained will be analyzed using a software that compares the bacterial, fungal, viral, or other microorganisms (beneficial or pathogenic) sequences present in the sample with those available in a database (known sequences that are published).  The method can provide relative quantitative data, generally expressed in percentages, of each organism found.  

  The NGS has been widely used in research and has allowed the discovery and characterization of important viruses such as Grapevine red blotch virus and many Vitiviruses. Presently, this technique is being applied commercially to test plant and soil samples for the detection of bacterial and fungal microorganisms.  It is recommended that a plant pathologist with expertise in bacterial, fungal, and/or viral taxonomy be available to associate the presence of the microorganisms found with disease symptoms (or potential disease development).

Why Results Can Vary When Submitting Samples

  Throughout my career I have heard the complaint of many clients about obtaining different testing results when samples are submitted to different laboratories.  This  can be due to operational errors by the lab personnel but can also could be due to submitting the wrong sample type or its labeling.  A false positive, is the reporting of a positive result when the sample is not infected.  This can be due to contamination in the lab but also due a mix-up in the field or in the laboratory.  There are many reasons for the reporting of a false negative: a lack of sensitivity of the assay used, the pathogen(s) are present in low concentrations, uneven distribution of certain pathogens in the vine.  Furthermore, submitting the wrong sample will not yield trust wordy results.  For example, once we received foliar samples to determine the cause of vine decline suspected to be caused by viruses.  However, the panel we ran showed no evidence of infection of the viruses associated with these symptoms. 

  When I visited the vineyard, during vine inspection I noted that every plant had huge galls caused by Agrobacterium vitis (now called Allorhizobium vitis).  Had the correct sample been submitted to the lab we would have been able to provide the correct diagnosis to the grower.

  To determine which laboratory is best suited for client’s testing needs, I frequently help perform inter-laboratory comparative tests.  This allows my clients to find a laboratory of choice to submit samples regularly.  The process involves submitting samples to different laboratories, requesting the same panel or tests and compare the results with what is expected.  For the process to work, it is important to collect and submit samples  with known infection status.  Further, the collector must be able to prepare homogeneous samples collected from the same vine material represented equally in each of the samples submitted to each laboratory.  My involvement in the process includes sample collection, interviewing  the laboratory manager to obtain more information on the personnel’s knowledge and capabilities, and analyses of results.

  Judit Monis, Ph.D. provides specialized services to help growers, vineyard managers, and nursery personnel avoid the propagation and transmission of disease caused by bacteria, fungi, and viruses in their vineyard blocks.   Judit (based in California) is fluent in Spanish and is available to consult in all wine grape growing regions of the word.   You can also schedule virtual vineyard consultations.  Please visit juditmonis.com for information or contact juditmonis@yahoo.com to request a consulting session.