Wine Grape Growing
ACCLIMATION. Phase during late summer when shoots stop growing and become brown and woody, and tissues acquire increased cold hardiness.
ACID FORMING FERTILIZER. Fertilizer which increases acidity and lowers the soil pH after it is applied and reacts with the soil.
ACID SOILS. Soils with a pH less than 7.0.
ADJUVANT. A pesticide adjuvant is broadly defined as any substance added to the spray tank, separate from the pesticide formulation that will improve the performance of the pesticide. This can include everything from wetter-spreaders to feeding stimulants.
AIRBLAST SPRAYER. It is a sprayer that uses a large, axial fan which directs spray into the vine canopy.
ALKALINE SOILS. Soils with a pH greater than 7.0.
ALLEYWAYS. Intentional breaks in vineyard rows to facilitate the lateral movement of equipment and workers.
AMERICAN HYBRID. Grape varieties which were produced in by crossbreeding (usually crosses between one or more native American varieties and one or more European traditional wine varieties).
AMERICAN VITICULTURAL AREA (AVA). American Viticultural Area (AVA) A delimited, geographical grape growing area that has officially been given appellation status by the Alcohol and Tobacco, Tax and Trade Bureau (TTB). Two examples of AVAs are Napa Valley and Sonoma Valley.
ANION. A negatively charged ion such as chloride, sulfate, carbonate, or bicarbonate.
ANNUAL WEEDS. Reproduce primarily by seed on an annual basis.
ANTHOCYANINS. The natural compounds found in the skins of red wine grapes which most strongly influence a red wine's color. These are the compounds that impart red, blue, or purple colors to the fruit and leaves of the grapes.
APICAL DOMINANCE. The tendency of the bud located at the highest point on a cane or shoot to grow the most vigorously.
APPELLATION. An appellation is a legally defined and protected geographical indication used to identify where the grapes for a wine were grown. If a wine label cites an appellation (e.g. Russian River Valley), 85 percent of the grapes must be grown in that appellation.
ARM. A short branch of old wood extending from the trunk or cordon on which canes or spurs are borne.
ASTRINGENCY. Astringency is the drying, roughing and sometimes puckering sensation that is experienced after tasting most red wines.
AVA. Stands for American Viticultural Area, and is used to represent a winegrowing region in the United States. These regional designations are controlled by the Federal Tax and Trade Bureau (TTB). Unlike most European appellations, an AVA specifies only a location. It does not limit the type of grapes grown, the method of vinification, or the yield, for example. Some of those factors may, however, be used by the petitioner who wants to define an AVA’s boundaries.
AVAILABLE WATER-HOLDING CAPACITY (AWC). The portion of water in a soil that can be readily absorbed by plant roots. It is the amount of water between field capacity and permanent wilting point. Usually measured in either %, in/ft, in/in, mm/mm, or m/m.
AXIL. Area of the stem between the upper side of a leaf and the supporting stem.