VITICULTURE

INTRODUCTIONIn this module, we will introduce the basic terms and concepts of viticulture the science of fine wine grape growing. We will also cover the annual life cycle of the vine and exactly what a grape vine needs to thrive and survive during the growing season. Remember, the growing season is in opposite months in the Southern Hemisphere.

MODULE OBJECTIVESIn this module you will learn:The basic terms and concepts of viticulture the science of grape growingThe anatomy of a wine grape and grape vineAn introduction to the annual life cycle of the vine

WHAT IS VITICULTUREViticulture is the branch of agriculture that involves the science of grape growing. It has been said that wine is the second oldest beverage after water; and grapes have been cultivated for the purpose of winemaking for thousands of years. It is only within the last century that grape growing has become elevated to its current status that is a combination of science and art.

ANATOMY OF A WINE GRAPEStem: usually removed before the grapes are pressed or crushed. Sometimes stems are included in red wine fermentation to increase the amount of tannins in the finished wine.Skin: skins of red grapes provide color and tannin. White wines are made without skin contact. The outside of mature grape may contain up to 100,000 yeast cells which may be used for fermentation.

ANATOMY OF A WINE GRAPEPulp: produces the juice, or must, as it is called during fermentation. The pulp provides water, fruit flavors, and sugar required for fermentation.Pips: or seeds are not crushed during the wine-making process as they contain bitter oils which would spoil the wine.

ANATOMY OF A GRAPE VINETendrilBunchLeafNodeCane/ArmTrunkSoil lineRoots

ANNUAL LIFE CYCLE OF THE VINEDormancyBud-BreakFoliage DevelopmentFloweringFruit SetRipening of FruitHarvestLate Harvest

DORMANCY: WINTERWhile the vines are dormant during winter, most of the work in the vineyard involves pruning or cutting back the canes leaving a few buds for the next seasons growth.

Weeping is the first sign of the new growing season, and takes place in:February for the Northern HemisphereAugust for the Southern HemisphereAt that time, the soil temperature rises to 50, warm enough for the vine roots to begin to collect water. Then sap rises up through the vine and oozes from the cane ends which have been pruned during the winter.Pruning for spring growth continues at this time but the vines are very vulnerable to early spring frosts which can freeze and kill the new buds.

BUD-BREAK-SPRINGIn spring, bud-break takes place some 2030 days after the vine starts to weep. The exact date varies with different grape varieties.MarchApril in the Northern HemisphereSeptemberOctober in the Southern HemisphereDuring bud-break the first new growth of the season appears. At this time spring pruning continues and the vines are secured to training wires. Aerating the soil is another important vineyard activity and the threat of frost continues.

FOLIAGE DEVELOPMENT: SPRINGFollowing bud-break, small shoots emerge from the vines and tiny green embryo clusters form. These small clusters will eventually become grapes. This foliage development happens in spring:AprilMay in the Northern HemisphereOctoberNovember in the Southern HemisphereAt this time the vines are sprayed for pests if necessary, and the vineyards are fertilized.

FLOWERING: LATE SPRING/ EARLY SUMMERFlowering of the vines takes place late spring/early summer, approximately eight weeks after bud-break:MayJune in the Northern HemisphereNovemberOctober in the Southern HemisphereThe weather must be dry and frost-free, and temperature is critical: 68 77 is optimum.

FRUIT SET: SUMMERFruit set takes place in summer:JuneJuly in the Northern HemisphereDecemberJanuary in the Southern HemisphereAfter flowering the fruit evolves rapidly, with the exact number of grapes per bunch varying with the specific grape variety. Spraying, summer pruning, and weeding all continue in the vineyard at this time.

RIPENING OF FRUIT: SUMMERThe fruit begins to ripen during verasion, the stage when the grape skins change color and the flavors begin to develop. This happens later in summer:August in the Northern HemisphereFebruary in the Southern HemisphereDuring this time the sugar content in the grapes increases. Also, the tart malic acid in them decreases while the more important tartaric acid increases. The seeds of the grapes also begin to mature as well as the tannins. In the vineyard spraying and weeding continues. Leaf pulling and canopy management (trimming the leaves of the vine to make sure the grapes receive enough sunlight to fully ripen) also takes place.

HARVEST: LATE SUMMER THROUGH MID FALLHarvest takes place late summer through mid-fall: AugustOctober in the Northern HemisphereFebruaryApril in the Southern HemisphereIt varies with different locations, specific grape varieties, and wine styles:Generally, whites grapes are harvested before red grapes. Harvest for sparkling wine grapes takes place before still wine grapes.Grapes used for late harvest, dessert wines are harvested last. Harvesting is done either by hand or machine. Most fine wine in the U.S. is made from hand-harvested grapes.

LATE HARVEST: LATE FALL THROUGH MID WINTERLate-harvesting grapes for dessert wines takes place:November - January in the Northern HemisphereMay - July in the Southern Hemisphere Some dessert wines are made from grapes affected with botrytis.Botrytis is a mold, that forms in some growing regions under certain conditions. While disastrous when it develops on red wine grapes (called gray rot), botrytis is responsible for many of the worlds greatest dessert wines.November in the Northern HemisphereMay in the Southern HemisphereWith the first hard frost, grapes for ice wine are harvested. With the arrival of winter, the growing season begins again with dormant pruning.

REVIEWYou should now have a good understanding of:The basic terms and concepts of viticultureThe anatomy of a wine grape and grape vineThe basic annual life cycle of a vine