How to choose vine driving system

The main objective of vine training systems is to develop and maintain the structure of the stem and woody branches with a determined shape and architecture, in order to facilitate pruning, canopy management, harvesting and vineyard mechanization.

Considering that the vine is a perennial species, the vineyards have a long useful life and the training system is implemented once and cannot be replaced over time, so the choice of the training system is a critical factor in implementation. of the vineyard.

Free, low conduction systems without support structures are the oldest and used mainly in regions with a temperate climate, where there is a need to raise temperatures especially during the grape maturation phase. In these systems, pruning is carried out in the form of a vase and in spurs, resulting in a smaller leaf area and productivity. On the other hand, high training systems allow the development of longer stems and primary arms, which favors greater leaf area and productivity.

The choice of the driving system must take into account different aspects such as: a) expected vigor, capacity and productivity; b) purpose of production (raisins, juice or wine processing and fresh consumption); c) ways of foliage orientation (vertical, horizontal and oblique); d) need for mechanization; d) soil and climate conditions and e) economic factors.

There is no universally accepted classification of driving systems, many variations exist between production regions and more modern adapted systems are continually being developed. Vertical or espalier training systems (Figure 1) are widely used for the cultivation of vines intended for wine production, and can have ascending or descending branch guidance.

However, the evolution of conduction systems over time aimed to improve the microclimate, by increasing the interception and distribution of solar energy, and increasing the exposed leaf surface. The exposed leaf surface varies depending on the components of the conduction system, such as planting density, stem height and canopy orientation, and when it is associated with maximum interception of solar energy, it allows a greater amount of energy to be captured, increasing photosynthetic activity and consequently production.

The use of split canopy was proposed to meet these objectives, with the main successful examples of these systems being Lira (Figure 2), Geneva Double Cortain (GDC), Duplex, Combi, etc. (Poni et al., 2016). In the last two decades, systems consisting of a mobile structure to increase the interception and penetration of light within the canopy have been developed, such as the Lys truss, the Lyre and modular espalier (Castro et al. 1995, Carbonneau, 2009).

On the other hand, Lira and espaladeira are characterized by high density of branches, which increases shading, and can affect bud fertility and adequate exposure of bunches to sunlight, which can compromise maturation and quality. of the grapes. To avoid these undesirable aspects, nutritional and irrigation management must seek to control vegetative growth and vigor, associated with management of the aerial part, pruning, defoliation and pruning of branches that are necessary, especially in more vigorous vines.

The main differences between the Lira and espaldeira training systems are that the first has two vegetation planes, promoting an increase in the density of buds and consequently of branches and bunches, which tends to result in increases in productivity. Furthermore, the microclimate in the cluster region is different, since Lira promotes greater separation of clusters and leaves, keeping the clusters out of the shadow of the leaves, improving the microclimate, which can favor grape maturation.

Horizontal systems, called trellis or pergola (Figure 3), and their variations such as the T-system, have the advantages of promoting maximum expansion of the leaf surface and greater bud load, at a height of at least 2m above the ground, which allows the movement of machines below the conveyance system. The layers of fruits and leaves are separated, which reduces the mechanical damage caused to the fruits by friction between leaves and bunches. Stains and dehydration of berries caused by direct sun exposure are also reduced in this conduction system, which can achieve very high productivity, and for these reasons they are the most recommended for the production of table grapes.

Influence of the driving system on agronomic performance

A long-term research was carried out at the Bebedouro Experimental Field, at Embrapa Semiárido, in Petrolina, Pernambuco (9°08'03” S, 40°18'28” W and 370 m) during the period from 2013 to 2017, totaling eight harvests, in grape cultivars for the production of Syrah red wines (Figure 3A) and Chenin Blanc white wines (Figure 3B).

The experimental vineyard was implemented in two training systems, Lira and espalier, using six rootstocks, with spacing between plants of 3m x 1m in espalier (3.333 plants per hectare) and 4,2m x 1m in Lira (2.380 plants per hectare), with localized drip irrigation system. The soil where the vineyard was located is characterized as a red eutrophic abrúptico plintossolic loam with moderate A, with medium texture and flat relief.

Variables related to vigor and production components were studied. Averages were obtained for three crops harvested in the first semester and five crops in the second semester of each year. Analysis of variance and comparison of means were performed using the Tukey test (p < 0,05).

The results obtained demonstrate that the vines of the Syrah and Chenin Blanc cultivars produced a greater number of bunches in the Lira training system (Figure 4), both on average for the first and second semester harvests. This occurs because the Lira has two vegetation planes and, therefore, a load of buds maintained after pruning that was approximately 30% greater than in the espalier.

As a consequence of the greater number of bunches, there was an increase in production per plant in the Lira training system in both cultivars and in the averages of the two annual pruning times (Figure 5). Lira increased the productivity of Chenin Blanc vines in the São Francisco Valley with increases of 25% and 41% for crops harvested in the first and second half of the year, respectively. In the Syrah cultivar, there was no increase in productivity in the training system in Lira, despite the greater number of bunches and production per plant, since in Lira, the density of plants per hectare was lower than in espalier. This productivity was approximately ten tons per hectare in the first half of the year and eight tons per hectare in the second half of the year, with similar values ​​in both training systems.

The training system had little influence on the bunch mass, obtaining bunches weighing 175g (average of harvests in the first semester) and 198g (average of harvests of the second semester) in Chenin Blanc vines trained in espalier and 206g (average of harvests of the first semester) and 250g (average of the second semester's harvests), in the Lira driving system. In turn, the Syrah cultivar presented slightly heavier bunches in the espalier (144g and 164g) than in Lira (130g and 139g).

The vigor of the vine was measured in this work by the mass of the branches eliminated after pruning. The training system in Lira increased the mass of Chenin Blanc vine branches in the averages of the two annual harvests, but in the Syrah cultivar, this increase was only observed in the average of the harvests of the second semester (Figure 6).

The mass of branches is used to obtain the Ravaz index, which is a parameter for evaluating the balance between production and vigor. Chenin Blanc and Syrah vines grown in Lira were more balanced, based on the Ravaz Index. Smart and Robinson (1991) suggested a ratio of 5:1 to 10:1 as optimal for moderately vigorous vines. In the Lira training system, the Chenin Blanc cultivar presented values ​​of 9,9 and 6,8, respectively, in the average harvests of the first and second semesters of the year, being within the recommended range and therefore with adequate balance. In turn, the Syrah cultivar also presented higher Ravaz indices in Lira compared to espalier, with values ​​of 8 and 5,2 for the harvests of the first and second semesters of the year, respectively. Despite the lower values ​​in the Syrah cultivar, they are still within the recommended range above 5:1 according to Smart and Robinson (1991). The balance between vegetative and reproductive growth is an essential tool to achieve quality and stable production over several harvests, with economic profitability for producers.

The closing thought

The Lira training system should be used in the cultivation of Syrah and Chenin Blanc vines in the São Francisco Valley to increase productivity and promote the development of more balanced plants, or with a better relationship between production and vigor. However, other aspects must also be observed when choosing the conduction system, such as its influence on the quality of the grapes and the wines produced.

Basic recommendations for whatever type of driving system used by the producer

1) Maximize the interception of solar radiation by leaves and bunches, with the aim of increasing yield, improving fruit quality and disease control.

2) Properly position trunks, string and sticks to avoid shading between plants.

3) Promote exposure to solar radiation in the renewal zone, that is, basal buds that will form spurs in the following pruning to maintain bud fertility and vine productivity.

Main advantages of lyre and espalier driving systems

1) Separation between the fruiting and vegetative regions (shoot ends).

2) It promotes aeration and reduces humidity inside the vineyard.

3) Lower implementation cost.

4) Independent rows, allowing the gradual expansion of the vineyard.

5) Allows mechanization of pruning and harvesting.

Patrícia Coelho de Souza Leão, Embrapa Semiarid

Growing Vegetables and Fruits October 2020

With each new edition, Cultivar Hortaliças e Frutas publishes a series of technical content produced by renowned researchers from all over Brazil, which address the main difficulties and challenges encountered in the field by rural producers. Through research focused on controlling the main pests and diseases in vegetable and fruit cultivation, the Magazine helps farmers in the search for management solutions that increase their profitability. 

chip