Wine Grape Growing
VARIETY. A clone, or series of related clones, propagated vegetatively from a single parent plant (monoclonal origin) or several genetically similar parents (polyclonal origin). Cultivar is used interchangeably.
VeRAISON. Stage of ripeness signaling the start of berry softening and color change (pronounced "veh ray zon," French).
VIGOR. Vigor is the quality or condition that is expressed in rapid growth of the parts of the vine. It refers essentially to the rate of growth. It depends on a combination of factors, including soil type, texture, and depth, water and nutrient availability, and variety choice. Inherently, some grape varieties are more vigorous (e.g., Syrah and Sangiovese) than others, which in turn can produce canopies with an excess amount of leaf area that require more intense management.
VINE CAPACITY. Vine capacity defines the maximum amount of shoots that the vine can support and fruit that will ripen.
VINE DENSITY. Important vineyard parameter, the number of vines planted per unit of area (usually acre).
VINTAGE. A term that describes both the year of the actual grape harvest and the wine made from those grapes. In the United States, the label may list the vintage year if 95 percent of the wine comes from grapes harvested that year.
VITICULTURE. The science of growing grapes.
VITIS. The scientific designation (genus) that includes all grape species.
VITIS VINIFERA. European grape species, which are the classic standard for wine making.
VMD. Volume median diameter (VMD) is a term used to describe the droplet size produced from a nozzle. VMD is defined as the diameter at which half the spray volume is in droplets of larger diameter and the other half of the volume is in smaller droplets.
VSP (Vertical Shoot Positioning). A method of vine training in which annual canes are tied horizontally to the wires and all new shoots are positioned vertically.