The aim of this work was to assess the effects of a cover crop, on the vegetative growth and production of grapevine. Three permanent cover crops: Agropyron elongatum (Host) Beauv. (tall wheatgrass), Trifolium pratense L. (red clover), the association Secale cereale L. - Bromus catharticus Vahl (cereal rye-rescuegrass) and two annual species: Sorghum sudanense (Piper) Stapf (Sudangrass), X Triticosecale Wittmack (triticosecale) were compared, with respect to no till soil management by herbicides application. The study was developed in a cv. Malbec vineyard with surface irrigation and in a vertical shoot positioning trellis system, located in Mendoza, Argentina. Parameters related to vegetative expression, grape production and its oenological potential were determined. Permanent covers of red clover, tall wheatgrass and the mixture cereal rye-rescuegrass restricted grapevine vigour compared to open soil (control), diminishing shoot growth, size of leaves and pruning weight. A lower yield production was also observed, with smaller clusters and a reduction of clusters per vine; with greater amounts of total anthocyanins and polyphenols. Permanent cover crops decreased titratable acidity and free amino nitrogen in the must; which slightly delayed alcoholic fermentation, although without stuck fermentation. In the wine tasting evaluation, wines coming from the three treatments with permanent cover crops were preferred by tasters and they appear with greater varietals authenticity. The introduction of a permanent cover crop reduced vegetative growth and yields of the grapevine, modifying the balance vigour/production of the vineyard, and therefore the composition of grapes and wine, without the need to conduct specific cultural operations.
