Grapevines are one of the most widely grown fruit crops in the world. Widely popular, grapes are regarded in many cultures as "the queen of fruits," since centuries. Many factors such as biotic and abiotic stress contribute for yield loss in grapes. Among the diseases, downy mildew which occurs throughout the crop cultivation seems to be more important. Downy mildew is a highly destructive disease of grapevines in all grape-growing areas of the world. Control of this devastating disease is more favorable achieved through the use of fungicides. This book aims to provide comprehensive information to understand the potential of various symptoms, occurrence losses and spread and management of grapes downy mildew pathogen by use of copper compounds.