Vine response to spur and cane pruning criteria differing in the respect to the sap flow paths is affected by plant material and growth conditions

The longevity and profitability of a great part of the world’s vineyards have been notably challenged by the increased incidence of the grapevine trunk diseases (GTD) in recent decades. Growing evidence shows that pruning, when done in an inappropriate way, enhances the GTD incidence. Winter pruning is an essential practice that allows directing the grapevine growth, as well as, adapting production to the productive potential of the plot. However, good pruning practices are being forgotten leading to more aggressive pruning techniques that increase the damage over the plants, causing a detrimental economic impact on the winegrowing sector. The aim of this study was to characterize the response of the grapevine when different criteria are systematically applied to conduct the cuts during pruning. Experiments were conducted on four adult vineyards, two planted in northern Spain (SP) and two in southern France (FR). SP vineyards were planted in ‘Tempranillo’ grafted onto Richter 110 and trained in a double cordon Royat while FR vineyards were planted in ‘Cabernet Franc’ grafted onto 3309C and trained in a simple Guyot. In the four vineyards, three alternative pruning systems were systematically applied: i) cuts leaving protection wood (PW); ii) cuts leaving protection wood and respecting the sap flow (PW+SF); and iii) aggressive pruning, without protection wood or respecting the sap flow (AGGR). In ‘Tempranillo’ trained in a double cordon Royat system, AGGR increased the pruning weight and the shoot weight during the winter pruning and tended to decrease the removed vegetation during the green pruning. In ‘Cabernet Franc’ trained in Guyot, PW+SF decreased the shoot number and pruning weight compared to AGGR and PW, however, green pruning was affected differently in the two monitored FR vineyards. Results evidence that the application of different criteria when performing cuts during pruning affects the grapevine growth, although their effects depend on the training system and the growing conditions. Maintaining these trials for at least three years will provide more robust data to determine the effects of pruning criteria on the development and production of the vines.