Composition of isabel grapes produced according to the conventional and organic systems.

There is an increasing demand for organic grapes by the grape juice industry of Serra Gaucha, the southernmost and most important Brazilian viticultural region. It is a humid and hot region during the summer time, climatic conditions that promot e the development of diseases caused by a series of fungi species, such as anthracnose, downy mildew, Botrytis and grape ripe rot. To control these diseases, and other problems caused by insects, growers apply fungicides and insecticides on the grapevines, which can result in residues on grapes and in grape juices. In addition, it is necessary to emphasize the impact to the environment ? air, soil, and groundwater contamination, − and to the human being.