Exploring the best trellis systems for vineyards

By Alyssa L. Ochs

For today’s modern, successful vineyards, trellises are much more than just a system of wires and posts. Trellises are crucial to a vineyard’s grape quality and productivity because of their impact on airflow, sun exposure and pest and disease management.

  If you’re starting a new vineyard or thinking of upgrading your current trellis system at an existing one, it’s important to know your options and carefully choose the right setup. In this article, we look at the various trellis systems available to vineyards and their pros and cons. By understanding their installation and maintenance requirements, vineyard owners can make the best decisions while factoring in specific grape variety needs, costs, labor demands and future goals.

Types of Vineyard Trellis Systems

  Alexander J. Wiesen, owner of Empire Trellis, told The Grapevine Magazine about the three main types of trellis systems vineyards use. The family-owned, Empire, Michigan-based company specializes in complete turn-key trellis installations and travels for installations within the U.S. and Canada.

  Wiesen explained that vertical shoot positioning (VSP) works well for quality wine production and allows for mechanization. VSP offers beneficial sunlight penetration and uniform ripening of the grapes.

  However, this type of system isn’t ideal for high vigor vines and requires more canopy management. If you don’t diligently remove leaves and thin shoots, canopies can become overly dense, which limits airflow and increases disease risk.

He shared that high cordon trellis systems are low-maintenance and straightforward. They’re ideal for warm climates and make vineyard work easier for crews, while being affordable to manage after installation.

  However, shading can be an issue, and there’s the potential for lower fruit quality with this type of trellis. You may experience unwanted shading below the fruiting zone, which can lead to muted flavors in finished wine.

  Meanwhile, a T-trellis or single wire system is cost-effective and suitable for mechanized pruning and harvest. This system often only requires a single horizontal wire that’s supported by posts, making installation and maintenance easier than other systems.

Yet, Wiesen advised that this approach gives vineyard operators less control over the canopy and that it may not suit premium varietals adequately. This low-input option is a practical choice but may lead to uneven ripening or difficulty managing grapevine diseases.

Trellis Offerings from Empire Trellis

  Empire Trellis offers various solutions for vineyards to consider for their trellis systems. For example, Wiesen’s company offers VSP trellises, which are among the most widely used systems among vineyards, especially for premium wine grapes. He said that VSP systems are ideal for varieties with upright shoot growth.

  Empire Trellis also offers high cordon systems, which are common in warmer regions and work well for vigorous vines. Wiesen said his company’s high cordon systems offer simplicity and help lower labor costs.

  There are T-trellis and single wire systems available at Empire Trellis that provide economical solutions for certain table grapes and are favored among mechanized vineyards.

  “We also work with growers to design hybrid or adaptive systems tailored to unique site conditions,” Wiesen shared while discussing his company’s customizable systems. “For each trellis system, we offer and distribute options for end posts made of wood, line posts made of metal or wood, tensioners, anchors, and wire.

Trellis Products from Walton Lumber  

  We also connected with Wil Hochstetler from Walton Lumber to learn more about additional trellis options. Walton Lumber is a Millington, Michigan company that goes beyond just selling posts, supplying the backbone of America’s vineyards, orchards, pastures, landscapes, and fences.

  The wholesale lumber company has been in business since 1932 and ships high-quality posts and fencing materials nationwide. It specializes in mill-direct shipments in truckload quantities and is committed to being a one-stop source for fencing and trellis solutions.

  “We offer all wood posts,” Hochstetler told The Grapevine Magazine. “We have an array of different species, including red pine, southern yellow pine and lodgepole pine.”

  Hochstetler explained that you can order the posts in a doweled or tapered form. Doweled means the posts are the same diameter from one end to the other. But with tapered posts, the ends vary in diameter, and the posts taper slightly from one end to the other.

General Installation & Maintenance Considerations  

  According to Hochstetler from Walton Lumber, “The best way to install wood posts is with a vibratory post driver mounted on an excavator.”

  Weisen from Empire Trellis emphasized how essential proper installation is to a trellis’ performance and longevity. He explained how the installation process begins with accurate post spacing and alignment, and then anchors must be properly installed, especially if you’re dealing with sloped or loose soil.

  Correct wire tensioning and spacing are vital when installing a new trellis. Weisen also mentioned the need to factor in drainage considerations to avoid post degradation.

 

Regarding maintenance, Weisen said that vineyards should check and re-tension wires each year. They should also inspect the posts for corrosion and damage.

  During these annual inspections, it may be necessary to replace damaged clips or cross arms. Throughout the year, vineyard operators should monitor for signs of stress from wind, machinery, or the vine load.

  “Well-maintained trellis systems are safer for crews, better for vine health and more cost-effective over time,” Weisen said.

Ensuring Your Trellises Last Long-Term 

  According to Hochstetler at Walton Lumber, “Treated wood posts will last 25 to 30 years.”

  Weisen agreed that a well-installed and maintained trellis system can last up to 30 years; however, longevity depends upon the materials used and the environment.

  To extend the lifespan of your vineyard trellis system, Weisen recommended using galvanized or stainless-steel components that will resist corrosion. You can also choose treated wood posts to prevent rot and aim to prevent soil saturation around the posts.

  Additionally, Weisen suggested that vineyards make a point to inspect and replace worn hardware before it fails. It is also important to take steps to protect trellis systems from tractors and other implements you commonly use in the vineyard.

How to Choose a New Trellis System  

  If you are looking to buy a trellis system for the first time for a new vineyard or upgrading from the system you already have, it’s important to consider several factors, such as your climate, slope, and grape varietals.

  “Post size is an important factor when planning a trellis system,” advised Hochstetler from Walton Lumber.

  “Are you planning to harvest the crop with a harvester?” he continued. “If so, you should use posts no bigger than four inches, so the posts do not interfere with the harvester.”

  “The strongest wood posts are southern yellow pine,” Hochstetler added.

Weisen from Empire Trellis said that grape varietals must be a consideration because some varietals need more sun or airflow, while others benefit from shade. He said climate is significant because vigor control and canopy exposure strategies differ between hot and cool regions.

  Soil conditions and vigor are also factors, as well as slope and topography.

“Steeper slopes may require shorter rows, special anchor systems or custom configurations,” Weisen said.

  When choosing a new trellis system, it’s also wise to keep future mechanization goals in mind as some trellis systems are better suited to machine pruning and harvesting. By staying focused on your budget and long-term goals, you can balance the initial cost of a trellis system with the long-term return on investment.

  An additional consideration Weisen mentioned is labor availability.  “Systems that reduce labor inputs, such as VSP with machine assist, are gaining popularity,” he said.

The Future of Trellis Systems  

  At first glance, trellis systems may seem relatively straightforward. Yet, as vineyards evolve with the times, so do the structural designs that support them.

  Trellis systems are seeing innovations and high-tech advances in terms of automation, materials used and data management to help grape-growers run efficient and adaptable operations.

  For example, Wiesen has seen increased automation in the industry and noted that trellis systems will need to adapt to accommodate machine automation with pruning, weeding, spraying, harvesting and shoot positioning.

  There are also new materials being explored for trellis systems, such as composite posts and corrosion-resistant alloys. These materials are gaining traction among forward-thinking vineyards because of their longer lifespan potential and sustainability.

  Meanwhile, planting and trellis design are beginning to be driven by integrating sensors and monitoring systems. An increasing number of vineyards are considering the impacts of climate change and intensifying weather patterns that affect growing grapes.

  “More vineyards are rethinking canopy structure to manage sun exposure, wind and water stress,” Wiesen said. “Sunshades are also becoming more popular.”

  Although technology will never replace the specialized skills and intuition of an experienced grape-grower, these innovations offer opportunities to make vineyard management more efficient and sustainable. By exploring these new tools, vineyard owners can overcome and adapt to changing conditions to spur on the next generation of successful winemaking.

Howdy! Welcome to grape breeding in Texas

By Andrej Svyantek, Ph.D., Department of Horticultural Sciences, Texas A&M University, AgriLife Research

Grapevine improvement is a numbers game. One metric ton of fresh wine grapes likely contains more than one million grape seeds (after accounting for variation in berry mass, seed set, rachis mass, and other factors). That’s a lot of potential grapevines. In the wild, grapes play this number game to their advantage, using their sweet sugars, colorful pigments, and delicate aromas to conscript birds and beasts to pick their berries and spread their seeds. When dropped to grow, grape seeds are deposited with a little bit of fecal fertilizer on their way to becoming the latest vine to try their hand against Mother Nature’s Phylloxera, freezes, and foliar diseases. Of all the many billions of seeds sprouting forth each year from compost piles and spread by bird splat, few may have what it takes to shape the growth of our anthropocentric grape and wine industries.

  Intentional crossing, imposed environmental constraints, and an applied breeder’s eye can help improve the odds of finding a vine worthy of training, naming, and growing as a new cultivar. These odds are further increased through the addition of tools that either enhance a breeder’s data collection process, boost selection accuracy, or expand the genetic variation in a meaningful manner.

  As a breeder, my goal is to reduce the amount of time and money spent on developing new grapevines by refining methodologies and technologies. As a grape grower, my goal is to create vines that are productive, durable, and simultaneously both easier and more economical for our farmers to grow. As a parent, my goal is to develop vines that are a delicious component of healthy eating habits. Finally, as a new Texan serving our farmers, my goal is to develop vines that are suited to the needs of our state so we can put food on the table and drink in the glass for our families and friends.

  Texas is graced with a rich and growing viticultural history. Early grapevine introductions date back to the 17th century Spanish missions that brought Vitis vinifera from Europe. This was followed by reciprocity with the exchange of North American Vitis to Europe for use as rootstocks, courtesy of the work of Thomas Volney Munson of Denison, TX. Cumulatively, our state is gifted with just about 171.9 million acres; it is home to many distinct viticultural regions and eight established AVAs. However, growing grapevines in Texas is not without challenges. We can lump our obstacles into abiotic (think drought, heat, and soil or water conditions), biotic (think Pierce’s disease, Black Rot, Grasshoppers or Phylloxera), and chaotic (think hurricanes and tornadoes, extreme temperature swings, and hail). As a grapevine breeder, each obstacle is a new opportunity for work. The open communication of farmers’ struggles helps breeders identify new targets and traits so that future cultivars are better adapted to the on-farm needs of our growers.

Genetic Variation, the Basis of Breeding

  As a diploid organism, bunch grapes (Vitis) have two copies of each of their nineteen chromosomes (one from each parent). Each chromosome contains unique sequences with genetic variation built up through chromosomal aberrations (structural changes to chromosomes) and point mutations (shifts in specific base pairs or their order). These genetic variations are shuffled through the process of meiosis when gametes are formed (pollen and ovules); the combined shuffling and inherent variation from both the seed and pollen parents give rise to seedlings, each drastically different from the next.

  Taking this variation into account, breeding a new grapevine variety is kind of like buying a winning lottery ticket several thousand times in a row. Each individual DNA base pair in a plant’s genome is what drives variation; they can be viewed as individual balls of the lottery where the winning alignment is a desirable expression of a trait contributing to a new cultivar. The genomes of our grapevines are composed of only about 500 million base pairs. This complexity leads to a considerable number of possible lottery tickets. When there is a difference at a single DNA base pair, we call it a single-nucleotide polymorphism (SNP). These SNP differences can shift the state of alleles (think of alleles as the varying forms of a given gene); when alleles differ, it drives shifts in the plant’s phenotype (observable traits associated with things like resistance, resilience, production, and quality).

  As plant breeders, we are playing the lottery with each specific cross we make. After emasculation and pollination, we are gambling that our new seedlings’ DNA will contain impactful SNPs that shape a majority of “winning” alleles across the approximately 30,000 genes of the Vitis genome. More “winning” alleles contribute to a more desirable phenotype for our growers, processors, and consumers. Plant breeders are playing the odds in attempting to align favorable parents, select favorable seedlings, and win the lottery for our growers with the goal of transforming meaningful genetic SNPs into industry shaping sips with each new grape cultivar released.

Fortunately, we are not gambling blindly like a bird plucking and plopping berries along a fence row. After crossing, the tools a plant breeder utilizes on the path to a new cultivar are phenotypic selection, marker-assisted selection, and genomic selection. These tools are critical, and their useful application is dependent on the presence of genetic variation within our crop plant.

Tools of the Trade

Genetic Variation:  For all crops in the U.S. (including grapevines), the genetic variation that allows breeders to serve growers is housed in the USDA Germplasm Repositories. These repositories are our most valuable resource for viticulture’s present and future success. They are our first ingredients when we start cooking up a new cultivar and they are our last line of defense as we battle against pests, diseases, and environmental challenges. Without these repositories’ collections of plant biodiversity, all breeding would be incapacitated and incapable of forging a better future for U.S. farmers.

Phenotypic Selection:  As breeders, phenotyping (measurement of a trait) is the single most important factor in selection and cultivar release. This process is critical for identifying plants that will perform for growers because it is an observation of the plant’s actual performance. For grapes, we have multiple phenotypes of interest. To serve our growers, we need environmental stress tolerance, biotic stress resistance, and yield. However, with grapes we are often as interested in improving chemistry and end-product quality, such as wines. Phenotypic selection is expensive and challenging for many traits due to the cost and time associated with data collection, the time required to wait for that trait to expose itself, the inherent sources of variation that impact plant performance, and the required environmental or biotic constraints for selection of certain traits (we cannot test for drought tolerance during a deluge). Traits that require mature plants (like wine chemistry), traits that require pest and disease pressure, and traits that require extreme climate events (like Winter Storm Uri to test the hardiness of vines in Texas) all can benefit from marker assisted and genomic selection techniques.

Marker Assisted Selection:

Researchers merge phenotype with genetic markers to develop molecular maps for breeders to follow on the path of grapevine creation. This process of associating traits with regions along chromosomes is called Quantitative Trait Loci mapping. The knowledge of which chunks of DNA explain variation in plant response become very important for breeders hoping to use this information for marker assisted selection (MAS). MAS allows a breeder to screen seedlings for things like disease resistance (without exposing them to pathogens) and wine color (without waiting for their fruit). MAS tools require a substantial investment of researchers’ time and effort, but they have a massive time saving impact for breeders in selection.

Genomic Selection:  For crops with many target traits (like grapes) that are under control of many genomic regions (like grapes) where farmers demand whole-plant improvement and high-quality cultivars (like grapes) a technique called genomic selection is necessary to address these highly quantitative traits. Developing an integrated genomic prediction platform for Texas and other grapevine breeding programs is essential to making the most of researchers’ efforts past, present, and future.

  In 2025, Texas A&M University launched a Grapevine Breeding Program into the turbulent waters of viticulture, research, and cultivar development. As a new program, our efforts are geared towards developing methods to rapidly screen promising progeny. This is geared towards increasing the odds of winning the lottery for Texas farmers using Vitis’ natural variation, informative markers, and genomic and phenomic selection procedures so we can deliver environmentally durable grapevines with rugged resistance for our growers. Starting a new grapevine breeding program at Texas A&M University is a challenge, but it is a numbers game that we can win for our farmers if we keep the numbers on our side.

Adiós For Now!

  My name is Andrej Svyantek. You can reach me at andrej.svyantek@ag.tamu.edu for collaborations, discussions, or just to describe your dream grapevine.

By: Judit Monis, Ph.D.

The symptoms of red blotch virus infection become more pronounced and progress in vineyards late in the summer towards the fall season. Therefore, it is timely to provide an update in this issue of the magazine.  In addition, this summer I attended a session on Grapevine red blotch disease at the 76th National ASEV (American Society of Enology and Viticulture) Conference held in Monterey, California.   Here I will summarize information on the biology, symptoms, transmission, and management of the virus responsible for red blotch disease plus a brief synopsis of two relevant ASEV oral presentations. 

Red Blotch Disease

  Red blotch is one of the most important viral diseases in grapevines.  The main symptoms are expressed in red-fruited grape varieties in the late summer/fall season.  It is difficult to distinguish symptoms of leafroll from red blotch disease. Because of this and until 2012 in which the virus was characterized, growers thought that their vines were infected by a yet uncharacterized species or strain of leafroll virus.  Grapevine red blotch virus (GRBV) genetic material is DNA rather than RNA, belongs to the Grablovirus genus  within the Geminiviridae family.   Foliar symptoms include reddening, or yellowing of leaves depending on the grapevine variety.  Very often, Grapevine red blotch virus infection displays leaf discoloration which usually appears spotty or blotchy.   In red fruited varieties, GRBV infected vines may display red veins, but red veins have also been observed in non-infected vines, and many red-blotch infected vines do not display red veins.   In white-fruited varieties red blotch disease displays yellow blotchy discoloration in leaves. genus Visual diagnostics can be complicated by the fact that grapevines often carry mixed infections of viruses and other pathogens.  The most important negative effect of red blotch virus infection is the reduction of sugar in fruit resulting in lower Brix values and delayed fruit maturity.  Two different genetic groups (clades) of GRBV have been reported but no differences in their biology or effect on symptoms in vineyards have been described.  Just as seen with leafroll, the symptom expression of GRBV infected vines is affected by climatic conditions and the author has noted differences in the effect on sugar reduction in sunnier and warmer areas (i.e., California coastal areas with more fog and lower sunshine yield fruit with lower sugar concentration than the same grape clones grown inland with more sun/heat exposure).

Transmission, Spread of Leafroll and Red Blotch Viruses

  Work by researchers at Cornell University and the University of California reported that the three-cornered alfalfa hopper (Spissistilus festinus) can transmit the GRBV in greenhouse and laboratory conditions.  It is interesting that grapevine is not the preferred host for Spissistilus festinus that prefers to feed on legumes, grasses, and shrubs.  Furthermore, the insect is not able to complete its reproductive cycle in grapevines.  Because the virus is spreading in areas where the three-cornered alfalfa hopper is not present, research is in progress to determine if other insects are capable of transmitting the red blotch virus.   Recently, it was shown that Tortistilus albidoparsus (another tree hopper) is a vector capable of transmitting GRBV.  The rapid expansion of this virus in vineyards  in USA and other countries (Asia, Europe, and South America ) was due to propagation and grafting of cuttings from infected vines.  

Virus Diagnosis and Disease Management

  The distribution and concentration of red blotch virus is uniform in infected vines.  In fact, the  detection of red blotch virus can be performed any time of the year.   Further, work performed in my lab showed that red blotch virus can be detected in high titers in any part of the vine.  The work showed that red blotch virus can be detected in any tissue tested, new or mature leaves, petioles, green or lignified canes, as well as cordons and trunks. 

  Keeping red blotch viruses out of the productive vineyards relies on clean planting stock programs.  Because the causal virus is graft transmitted and has biological vectors it is important to implement a monitoring and sampling program at the nursery and production vineyards.  Vines that are symptomatic or that test positive must be removed from the vineyard to avoid spread.  Depending on the disease incidence (I have developed a statistical sampling formula to calculate and help make decisions), the removal of a few vines or the whole vineyard is recommended. The use of chemical control, although might be used to control GRBV vector is not presently recommended. However, the choice of cover crops that are less appealing to its insect vector’s diets might minimize their presence in the vineyards.  

Highlights of ASEV Presentations

Effect of GRBV in Wine Quality:  Raul Cauduro Girardello (University of California at Davis) presented research to determine if the length of time the vines are infected with GRBV have an effect on wine sensorial and grape chemical quality components.  The study was performed with wine produced using grapes grown in an infected Merlot vineyard block located in Paso Robles (California Central Coast).  The parameters analyzed in grapes were: soluble solids, titratable acids, pH, and phenolic composition. The wine produced were analyzed for basic chemical composition, volatile and phenolic compounds. In addition, descriptive analyses provided and evaluation of the wine’s sensory attributes.  The study found no substantial difference in the analyzed fruit and wine parameters regardless of the time since the vines were infected.  Interestingly, wines produced from recently infected vines were affected (not significantly), sensorially.  Furthermore, the descriptive analyses demonstrated that panelists were able to distinguish the wine’s attributes based on how long the vines were infected.  It would be interesting to learn if the results would be different in other growing areas such as Sonoma and Napa Valley vineyards.

Control of GRBV using Spray-Induced Gene Silencing:  Christian Mandelli (Oregon State University, Corvallis) presented research on the application of double stranded RNA (dsRNA) to induce what plant virologists know as RNA interference.  Compared with animals, plants do not have an immune system to defend themselves from the infection of viruses (or other pathogens).  However, plants have developed a gene-silencing mechanism to respond to viral infections known as RNA interference (RNAi).  Pathogen derived resistance has been applied to many plant species including grapevine (i.e., development of rootstocks resistant to fanleaf disease) using genetic engineering methods.  Unfortunately, these rootstocks are not being used due to the lack of popularity and acceptance of genetically modified organisms (GMOs) by consumers.  The study presented at the meeting proposes to bypass the use of GMOs by spraying small portions of double stranded RNA (dsRNAs) onto plants.  The researchers report the finding of  “hotspots” in the GRBV genome that can be targeted by the plant’s RNAi machinery to induce viral gene silencing, inhibiting the viral replication, ultimately suppressing viral infection.  If the research is successful, a method for foliar application (spraying) of small interfering dsRNAs  would provide resistance to GRBV replication and therefore reduce the detrimental effects of the virus.  The project is interesting  because the application of spray-induced gene silencing would provide a non-GMO strategy that could mitigate GRBV infection in vineyards.

Conclusions

  Exciting new research is promising and may allow growers and nursery personnel to control GRBV infection.  However, the production of clean planting grapevine stock still remains the number one prevention strategy to keep newly planted vineyards free of viral and fungal diseases.  Presently, there is no clear recommendation on the needed isolation of foundation or nursery mother blocks and production vineyards. A prudential distance and isolation will help avoid infection of clean planting stock from diseased blocks. We know that the lack of symptoms does not correlate with a healthy diagnostic result.  Therefore, it is recommended to test a statistical sample of the nursery propagated material to confirm the material’s health status. Obviously, nurseries and growers must determine the health status of grapevine stock prior to planting to avoid the propagation and/or introduction diseased vines to the vineyard.  But as important is to isolate and monitor newly planted vineyards to avoid the introduction and propagation of disease via insect vectors. 

  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 the vineyard.   Judit (based in California) is fluent in Spanish and is available to consult in all wine grape growing regions of the word.  Please visit juditmonis.com for information or contact juditmonis@yahoo.com to request a consulting session