Composição físico-química da uva e do vinho Tannat em diferentes coberturas inorgânicas do solo

Abstract

One of the main purposes of using inorganic soil cover is to improve the physical and chemical characteristics of grapes and wine. In addition to this technique, the defoliation that is very common in vineyards also aims to allow more light and air to enter the canopy, providing better color and ripening of the grapes. Therefore, the objective of this work was to evaluate in three experiments, the effect of different soil cover materials in different phenological periods and harvests, cover with different colors and the association of defoliation with soil cover on the quality of Tannat grapes from the region of Rio Grande do Sul Campanha. Treatments with plastic canvas and non-woven fabric, both in white, were used in the period of fruiting and color change, in the 2018 and 2020 seasons. It was observed through the results that the treatment with TNT in the period of maturation in the 2020 harvest it was superior to the other treatments for the average number of bunches per plant. For the variables indicating sugar in the must, the best treatment was with white canvas in the color change in the 2018 harvest. In wine, the anthocyanins and the color intensity were higher in the fruiting with TNT in the 2018 harvest. Therefore, for these conditions, the harvest had great influence on the treatments, being that the soil cover can be an alternative to improve the physical and chemical characteristics of the Tannat grape. For this reason, this work aimed to evaluate the effects of an inorganic material as a soil cover together with the defoliation of plants on fruit yield, quality of must and quality of wine. The treatments with white plastic canvas arranged in the period of fruiting and partial defoliation, in the 2020 harvest, were worked out. We can conclude from the results that the treatment with soil cover without defoliation had greater mass of the bunches. The other variables of the must and wine did not show statistical difference. Therefore, for these conditions, defoliation had no influence on treatments, and ground cover can be an alternative to improve the physical characteristics of the Tannat grape. The experimental design was completely randomized conducted in the 2018/2019 harvest, where the plants were covered during the maturation period of the grapes, consisting of four treatments and four repetitions: soil cover with non-woven fabric (TNT) in blue, yellow colors and red and the witnesses without coverage. After the harvest, physical analyzes of the grapes and chemical analysis of the must, vinification, and later the chemical analysis of the wine were carried out. The data obtained were submitted to the Duncan test at 5% significance level. According to the results found, we can observe that the soil cover with yellow TNT provided a lower color shade of the must and influenced the higher alcohol content of the wine. Therefore, the different colors in soil cover can modify some characteristics of the grape and Tannat wine.