Remediação do dessecamento de ráquis em uva de mesa Vênus com a utilização de plantas de cobertura

Abstract

Rachis desiccation develops in the apical portion of the bunch and is related to excess potassium in the soil and competition for calcium and magnesium for foliar absorption. It provides poor quality fruits, with low sugar content at the apex that are the end of the bunch due to the change in the distribution of carbohydrates. The Cultivar Vênus table grape presents this disturbance very accentuated, affecting the production and causing the depreciation of the fruits. The objective of this work was to use cover crops to remedy the excess of potassium in the soil, competing and decreasing the amount of nutrients available for the uptake of the vine. Three treatments consisting of cover crops were used: black oat (Avena strigosa), rye (Secale cereale L.), and the control with spontaneous vegetation. Nine plants were used per treatment in single plots, with the planting of cover crops in the lateral strips of the vines. The border was disregarded and each treatment had seven repetitions. The following parameters were evaluated: foliar nutritional analysis, incidence of rachis desiccation, average bunch weight, total soluble solids content, titratable acidity and ratio. In general, the foliar contents of Potassium, Calcium, Magnesium, Manganese and Sulfur are insufficient, while Nitrogen, Phosphorus, Zinc, Copper and Boron are normal in all treatments. Great severity of rachis desiccation occurred in all treatments. There was no difference between the control and the cover crops black oat and rye in the parameters evaluated. [resumo fornecido pelo autor]