Michigan Vineyards Thrive with Guyot Pruning System

By Andi Anderson

Over the past four decades, Michigan's wine industry has transformed significantly. Once dominated by cold-hardy hybrids, the state now boasts approximately 70% of its vineyard acreage planted with Vitis vinifera varieties like Riesling, Pinot Noir, and Chardonnay. This shift is attributed to advancements in viticultural practices, including site selection, canopy management, and disease control, coupled with a warming climate.

A pivotal change in vineyard management has been the adoption of the Guyot pruning system, paired with vertical shoot positioning (VSP) trellises. 

This method, well-suited for cool climates, involves annually renewing fruiting canes, allowing for better control over crop load and improved fruit quality. The system's compatibility with mechanization also enhances efficiency in vineyard operations.

Key guidelines for effective Guyot pruning include:

• Spur and Cane Positioning: Prune the renewal spur to two buds, ensuring the distal bud produces the next year's fruiting cane.
• Maintain a Low Vine Head: Select renewal spurs close to the trunk to facilitate uniform shoot emergence and prevent the crown from rising.
• Manage Bud Count According to Vigor: Adjust cane length and bud number based on vine vigor to maintain balance and avoid overcropping.
• Understand Bud Fertility: Recognize that certain cultivars may have lower fertility in basal buds, necessitating adjustments in pruning practices.
• Select the Best Cane: Choose healthy, well-oriented canes for fruiting, keeping backups in case of damage during pruning.
• Avoid Inward-Facing Shoots: Exclude canes oriented toward the row interior to prevent damage from equipment.
• Protect Crown Buds: Avoid injuring basal buds near the cane's base, as they are crucial for developing next year's renewal spurs.
• Minimize Cuts on Old Wood: Make pruning cuts on two-year-old wood to reduce susceptibility to trunk diseases.
• Respect the Desiccation Cone: When cutting into older wood, leave space for the natural desiccation cone to form, minimizing dieback.

The Guyot system's adaptability makes it relevant beyond Michigan, benefiting other cool-climate regions like New York's Finger Lakes and Ontario's Niagara Peninsula. By focusing on vine balance and precise pruning, growers can achieve consistent yields and high-quality fruit, essential for premium wine production.

As Michigan continues to refine its viticultural identity, the Guyot pruning system stands out as a cornerstone practice, aligning with the state's climatic conditions and supporting its reputation for producing exceptional wines.

Photo Credit: istock-jhvephoto