Best Practices
Pruning Premium Wine Grape Varietals
The annual dormant pruning of vineyards on the North Coast has great impact on the growing season. The pruning task is made up of two main operations: pre-pruning and pruning.
Pre-pruning is used to help spread out field work (with the result being more sustainable "year round" employment for staff), control total pruning costs, and allow for disease management. In limited situations, late pre-puning can facilitate a later bud break, resulting in passive frost protection. We covered this in an earlier post.
Pruning is done after pre-pruning and will help determine yield and quality. Many consider the final pruning of the vineyard as the most important operation of the year. Pruning introduces additional variables including: labor availability, employee safety, hand pruner’s skill, cost and timing of operations. Walsh is currently experimenting with the use of electronic hand shears to prune a vineyard (see photo below).
Shown is an electric pruning shear used by Walsh. This tool significantly lowers the physical impact on employees and helps specifically with cane pruning systems, because the tool facilitates making large cuts in older wood effortlessly.
Employee conditions and safety, are priorities for both machine and hand pruning operations, specifically:
Field conditions for both machine and manual pruning during operations
Skill level and management required for supervision and training
What height the head of a vine is established or the cordon is placed?
Safety equipment needed: Glasses, gloves
Determining all pruning equipment, as well as R&M strategies required for both hand and machine operations
Pruning can be a risky operation. It is important that vineyard operators educate, train, and research this topic. Your vineyard manager must be an expert, with regards to pruning safety.
General Pruning Concepts:
Identifying the desired quality while maximizing yield suggests understanding the balance in a vineyard between vine vigor and cropping levels
Historical yield and maturity data
Wine sensory analysis from prior crops on that site
Aerial imagery (NDVI) may help evaluate weak and vigorous areas allowing the grower to develop pruning pre-pruning and finish pruning strategies
Cool or warm (hot) climates may affect considerations: cane vs cordon & bud fruitfulness should be considered before final pruning has been done.
Finished pruning on the North Coast is more typically done by hand and will not require use of mechanized methods. Significant variables include: manual hand labor cost, labor needed, and skill level required.
Trellis type and structure
Canopy Characteristics to Consider When Pruning:
Vine vigor measurements (pruning weights, shoot length etc.)
Shoot lengths
Bud counts
Shoot density
Leaf layers
Pruning weights
Ultimately pruning will impact canopy micro-climate, the resulting wine quality, and disease control. Walsh pruners insure that the canopy will have adequate sunlight throughout the canopy; leading to appropriate air circulation and good spray penetration. The average Walsh pruner has been with the company for 10+ years.
Outside links worth visiting for more information on safety and pruning operations: