Viticulture Flashcards
When does budbreak usually occur?
March or April (Northern Hemisphere)
- the first small shoots and leaves will break through the buds left intact by winter pruning
- at this stage, the vine is vulnerable to frost.
When does flowering occur?
6-13 weeks after the initial budbreak, depending on the climate
What takes place during flowering?
Embryo bunches (small green clusters) bloom into small flowers for about 10 days, and the self-pollinating grapevine begins the process of fertilization, which leads to fruit set
- As the vine flowers, it is extremely susceptible to the damaging effects of cold, frost, and wind
What happens during veraison?; when does veraison occur?
Sugars are moved from the leaf system to the fruit, and the grapes begin to truly ripen. The grapes soften and change color - turning from green to red-black or yellow-green - and acidity decreases.
Veraison usually occurs in August (Northern Hemisphere)
When does cane ripening occur?
In tandem with veraison (in August), as the stems on each shoot begin to lignify, accumulating carbohydrates to sustain the plant through the winter
What is vendange?
harvest
What is the preferred mean annual temperature for vines?
btwn 50 - 68°F, with an ideal of 57 °F
What is the avg. summer temperature required for red grapes to successfully ripen?
70°F
- white grapes prefer an avg. summer temperature of 66°F
What is photosynthesis?
With the aid of sunshine, plants convert carbon dioxide into organic compounds, including sugars
Explain cordon training.
cordon training - the vine has at least 1 permanent cane that extends from the trunk called and arm or cordon. The arm or cordon grows thick and gnarled over time, and has fruit-bearing shoots will emerge from it each season.
What is the min. amount of sunshine required to support viticulture?
1,300 hours
