Lyre / U-System — Horizontally Divided Double-Curtain Trellis for High-Vigor Sites

The Lyre, or U-system, is a horizontally divided trellis where a single vine trunk branches into two bilateral cordons that diverge laterally and then run along parallel cordon wires. Viewed from the end of the row, the canopy silhouette resembles the shape of the musical instrument that gives the system its name. Shoots are managed by vertical shoot positioning, angling upward and outward at roughly 10 to 15 degrees from vertical to create two distinct, separated canopies per vine. The bearing wood consists of equidistantly positioned spurs along each cordon, and support for the trellis normally consists of row and end posts set into the soil to form a V-shaped or U-shaped configuration.

• Single trunk divides into two bilateral cordons, each running along a separate parallel cordon wire spaced approximately 1 meter apart horizontally
• Shoots are trained upward by vertical shoot positioning, separating the two canopies and opening the center to light and air
• Cordon wires are positioned at roughly 1 meter above ground, with moveable catch wires above to support growing shoots
• Horizontally divided design requires wider row spacing than VSP or vertically divided systems, increasing land and trellis costs per hectare

The core rationale for the Lyre system is managing high-vigor vineyard sites where a single-curtain VSP trellis becomes overwhelmed by vegetative growth. On fertile soils with ample water, vines trained to VSP produce dense, shaded canopies that compromise fruit ripening, encourage fungal diseases, and demand repeated hedging passes. By physically separating the canopy into two curtains, the Lyre increases the proportion of leaf area exposed to photosynthetically active radiation and improves airflow through and around the fruit zone. Divided canopy systems such as the Lyre can simultaneously improve fruit composition and support higher yields by expanding exposed leaf area and increasing bud numbers retained per unit of row length.

• Open canopy structure exposes more leaf area to direct sunlight, supporting sugar accumulation and aromatic development in the fruit
• Improved air circulation through the separated curtains reduces humidity around bunches, lowering botrytis and mildew pressure
• Suits medium-to-high vigor sites where VSP becomes chronically shaded without intensive and repeated summer hedging
• Divided canopies are inappropriate in low-nutrient soils or where rainfall and irrigation are limited, as the system demands strong vegetative growth to function correctly

Establishing a Lyre trellis requires a more complex and costly infrastructure than a standard VSP, including sturdy posts, bilateral wire guidance, and careful shoot positioning throughout the growing season. Once cordons are established, ongoing management involves positioning shoots upward and outward into the two curtains at least twice after bloom to maintain canopy separation and keep the center of the vine open to sunlight. One advantage the Lyre has over the Geneva Double Curtain is that fruit is positioned under the canopy rather than on top, reducing the risk of sunburn and excessive phenolic accumulation that can occur with exposed fruit on downward-trained systems. The system is compatible with mechanical harvesting, though the divided structure requires careful calibration of equipment.

• Shoot positioning must be performed at least twice after bloom, combing shoots outward and upward to maintain separation between the two curtains
• Fruit hangs beneath the canopy in the Lyre, providing shade protection against sunburn that can be a risk in GDC and other exposed-fruit systems
• Higher infrastructure and labor costs at establishment, but the system can justify its investment through improved fruit quality on high-vigor parcels
• Compatible with mechanical harvesting when properly configured, unlike some other divided-canopy designs that present access challenges

The Lyre and the Geneva Double Curtain (GDC) are both horizontally divided canopy systems, but they differ fundamentally in shoot direction and variety suitability. In the GDC, cordons are trained high and shoots are encouraged to hang downward, making it well-suited to American cultivars and French-American hybrids that naturally trail. The Lyre positions cordons lower and trains shoots upward, matching the upright growth habit typical of most Vitis vinifera cultivars. A further practical distinction is that the Lyre places fruit under the canopy, reducing sunburn risk, while GDC positions fruit at the top where it can be more exposed. Both systems are designed for high-vigor, productive sites and require wider row spacing than single-curtain trellises.

• GDC trains shoots downward from high cordons; Lyre trains shoots upward from lower cordons, suiting the upright habit of most Vitis vinifera varieties
• Lyre fruit is positioned under canopy cover; GDC fruit sits exposed at the top of the hanging curtain
• Both are horizontally divided, spur-pruned systems designed for high-vigor, medium-to-high-yield sites requiring canopy division
• GDC cross-arm configuration differs structurally from Lyre's bilateral diverging cordon design; both require wider row spacing than vertical systems

The Lyre system remains a specialist tool rather than a mainstream choice, applied where site vigor genuinely justifies the additional infrastructure and management complexity. In Bordeaux, Château Bertinerie has implemented the Lyre across its entire vineyard with the direct long-term guidance of Carbonneau himself, and is cited as one of the largest Lyre-trained estates in France. Beyond Bordeaux, the system has found documented use in Oregon, where estates such as King Estate use Lyre for high-vigor blocks of Pinot Gris and Gewurztraminer on fertile soils. Bel Lago Winery in Michigan has adopted the Lyre specifically for Cabernet Franc, citing the system's suitability for that variety's upright growth habit. Research comparing training systems on Merlot by Carbonneau and colleagues at Montpellier found the open Lyre produced wines among the most concentrated of all tested systems under moderate-vigor conditions.

• Château Bertinerie, Bordeaux, is cited as among the largest Lyre-trained estates in France, managed with direct input from Carbonneau over more than 30 years
• King Estate Winery in Oregon uses Lyre on approximately 5 percent of its 465-acre estate, primarily for high-vigor Pinot Gris and Gewurztraminer blocks
• Bel Lago Winery in Michigan installed Lyre specifically for Cabernet Franc, citing the variety's upright growth habit as a strong fit
• Research by Carbonneau and colleagues found open Lyre wines among the most concentrated of tested training systems under moderate-vigor conditions for Merlot

The Lyre system performs best where site vigor provides the vegetative growth required to fill two canopy curtains effectively. It is most commonly encountered in productive, fertile sites across the New World and in selected high-vigor European parcels, particularly where soils are deep and water availability is reliable. The system is a poor match for low-vigor, low-nutrient Mediterranean environments or for sites where rainfall or irrigation is insufficient to sustain a full double canopy. In cool climates such as Oregon and parts of England, it has been used on higher-fertility soils to manage vigor and improve ripening. Carbonneau himself described the Lyre as best suited to temperate climates, and compared its open, elevated structure to a more uniform and linear version of the traditional Gobelet system.

• Best suited to fertile, well-watered sites with medium-to-high vine vigor; unsuitable where soil nutrition or water is limited
• Used in Oregon, Michigan, parts of Bordeaux, England, and various New World regions where site fertility creates canopy management challenges
• Not appropriate for low-vigor Mediterranean environments where head-trained bush vines or VSP on narrow spacing remain more practical and economical
• Carbonneau described the Lyre as well-suited to temperate climates and noted its conceptual relationship to an open, uniform Gobelet