Composição físico-química de Vitis vinifera ‘Cabernet Sauvignon’ sob diferentes clones, níveis de poda e desfolha

Abstract

The management of the vegetative canopy can modify the architecture of the vine and have effect on the components of production of the plant. Like the pruning, the elimination of the leaves in the period of maturation of the vine, allows the obtainment of higher quality grapes. Another factor that has been allowing expressive gains in the viticulture in terms of quantity and quality is the clonal selection. Therefore, the goal of this work was to evaluate the physical and chemical composition of Vitis vinífera„Cabernet Sauvignon‟ under different levels of dry pruning correlating factors like clones, defoliation and homogeneous areas. The experiment was realized in the periods of 2015/2016 and 2016/2017 in the Bueno Bellavista Estate Vineyard that is located at BR 293, Km 143, in the city Candiota-RS. The experimental area totalizes 4,6 hectares of grapes of the Cabernet Sauvignon variety, implanted in 2010 grafted on rootstock „101-14', clones 169 and 685, density of 4545 plants per hectare, conducted on vertical trellis system. The experimental design was entirely randomized composed by two factors, where each repetition was composed by 3 plants, totalizing 48 plants/area and 96 plants to the total. The work was divided into three experiments: Pruning x Clones, Pruning x Defoliation, Pruning x Area, where the prunings were performed in spore cord, totalizing two gems for each spur. The plants were pruned in order to allow it to stay with 8 spurs with 16 gems, 7 spurs with 14 gems, 6 spurs with 12 gems and the witness with no alteration in the number of gems, according each treatment. The variables analyzed were: average mass of the bunches, average mass of the rachis, must yield, total soluble solids, total sugars, density, reducing sugars, pH and acidity. The obtained data were subjected to analysis of variance and Tukey test by the RBio program. In the experiment 1 (pruning x clones), the results showed that there are significant differences between the clones 169 and 685, being that the 685, showed to be superior compared to the clone 169 to the analyzed variables. In the experiment 2 (pruning x defoliation) the results of the physical analyzes showed that plants with defoliation showed to be superior to the variable average mass of rachis, density and total sugars, not having interaction between the factors. In the experiment 3 (pruning x area), it is concluded that there are significant physiological differences in the plants located on internal homogeneous areas of the same vineyard, just like there is interaction between the factors Pruning x Area.