Vine Training in the Veneto
- By Jacky Blisson MW
- 06 Jan 2021
- 5 MIN
- Level 301
Vitis vinifera is a liana, meaning that, left to its own devices, it will use trees or any other vertical support to climb upwards in search of sunlight. Since its domestication, some 6,000 to 8,000 years ago, a multitude of vine training systems have been developed.
Pergola Vine Training in the Veneto
The pergola system is one of the most ancient methods of cultivating grapevines, seen as a natural succession to the Etruscan system of training Vitis vinifera up elm trees. The pergola system consists of a series of vertical poles supporting an overhead trellis system. The vine branches are attached to the trellis wires, forming a canopy.
Various forms of pergola training systems have been employed in Italy, with many still in use today. In the Valpolicella, Soave, and Bardolino regions of the Veneto, the most popular such system is pergola Veronese. In this system the overhead trellis framework is tilted at a 90° angle, with one to four shoots of 10 to 15 buds left on each vine.
A Move to Mechanization
By the 1980s and notably into the 1990s, negative critical opinion on pergola training systems had spread throughout Veneto and much of Italy. The low vine density of pergola training was felt to stimulate excessive vegetative growth and high vine crop loads resulting in poor quality grapes. Pergola training is labour-intensive as vineyard work cannot be mechanized. Pergola systems are also expensive to install. Masi Agricola oenologist Andrea Dal Cin estimates the total additional cost at 40% more than Guyot-trained vineyards in their Valpolicella DOC vineyards.
The EU and Italian governments sponsored incentive programs to help Venetian wine producers switch over to the Guyot training method, a form of cane pruning highly prized in quality wine regions like Burgundy. While this proved a positive move for many producers, it had a number of detrimental effects on the vineyard landscape.
Pulling up pergola-trained vines and replanting led to a significant loss of old vines in the region, and with it a loss of genetic diversity, as well as a decrease in plantings of many indigenous varieties deemed less popular at the time.
Renewed Interest in Pergola Veronese
Recent studies have revealed qualitative advantages to pergola Veronese which is leading key Veneto producers to revisit this traditional training method. The most significant finding is that its dense, sprawling canopy provides better shade for grapes in increasingly hot growing seasons.
A three-year study conducted by Masi Agricola on Corvina vines showed that those trained on pergola Veronese experienced less colour bleaching and retained higher anthocyanin levels. In comparison, the Guyot-trained vines developed thicker skins to protect against sunburn, leading to firmer, more astringent tannins. Similar research conducted in Soave by Dr. Federica Gaiotti, demonstrated that delicate aromatic compounds in Garganega were better preserved in the well-shaded pergola Veronese vineyards.
Masi found that the shaded pergola Veronese vines ripened up to two weeks more slowly, yielding grapes with superior sugar/acid balance and fuller phenolic maturation. Based on these findings, they are moving back to pergola Veronese training for future plantings in their best hillside vineyards. However, they will continue to use Guyot training in more marginal, valley floor sites where maximum sunlight exposure is needed to ensure full ripening.
Pergola Veronese is also thought to reduce fungal pressure due to increased air circulation under the canopy. However, conflicting points of view exist on this point, as Guyot-trained vines generally have greater airflow within the canopy.
While Soave has maintained the tradition of majority pergola-trained vines, Valpolicella’s landscape is more mixed nowadays. Cost, desired production volumes, site, and quality ambitions are all significant considerations producers face when deciding upon their training system.