Wine Grape Growing
YIELD. The amount of wine or grapes produced per unit area, usually measured either as ton/acre, tons/ha or, in much of Europe, hl/ha. Many factors such as planting density, pressing regime, grape variety, and style of wine affect the conversion of weight of grapes into volume of wine but 1 ton/acre is very approximately equivalent to 17.5 hl/ha.
YIELD-TO-PRUNING-WEIGHT RATIO. A measure of the balance between vegetative growth (current season) and fruit production.