Viticulture- part 2 Flashcards
In the Northern Hemisphere, when the growing season begins and ends?
Begins with budbreak in March or April, and ends with harvest sometimes between August & November.
In the Southern Hemisphere, when the growing season begins and ends?
Budbreak occurs in September or October, with harvest between February and May.
What is happening with the vines when the temperatures begins to warm and rich 10 degrees Celsius?
The vine begins transporting sap containing nutrients and energy stored in the roots to the buds to initiate shoot growth.
What is happening with the grapes during “Veraison”?
The grapes start to change their color, plus flavor and sugar begin accumulating in the fruit, acidity and astringency decrease and the fruit begins to soften.
What does pruning means?
Last year’s vegetative growth is removed to make way for the new growth during the coming season. During pruning viticulturists determine the number and position of buds that will turn into shoots.
How can rain or irrigation affect the fruit in negative way?
Can cause the fruit to swell and may dilute sugar, acid and flavor concentration.
Explain why pests & diseases are problem for vineyards?
Pests and diseases threaten health and longevity as well as the quality and quantity of the current season fruit.
Phylloxera is native to?
Mississippi Valley of the eastern United States
In which year Phylloxera was discovered in Europe and where?
1866 in the southern Rhone France.
What type of pests are Nematodes?
They are parasites, that feet on roots, limiting the capacity of the vine to uptake water and nutrients.
Insects are differentiated by the type of feeding that they do, name 2 sucking insects?
leafhoppers
sharpshooters
How is powdery mildew called in French?
Oidium
*Affects all green parts of the plant, marking grapes, leaves and shoots with its white dusty mildew growth, first recorded in England in 1847.
How growers tret powdery mildew in the vineyards?
With sulfur spray, or systemic fungicides on the canopy.
How is different (Downy Mildew from Powdery Mildew)?
Spreads only trough water, attacks green plants especially young shoots and leaves.
Causes oily yellow spots on leaves
*Treated trough regular spray of Bordeaux blend, a mixture of sulfur copper and lime
What is Organic Farming?
Organic Farming avoids the use synthetic chemicals that are commonly used in farming such as:
conventional fertilizers
herbicides
pesticides
systemic fungicides
*Many people believe incorrectly that organic and biodynamic vineyards do not use fungicide sprays. In fact, organic fungicides are typically applied more frequently than their conventional counterparts
How is Biodynamic farming different than Organic farming?
Biodynamic shares many of the principles of Organic farming, with key distinction for Biodynamic with 9 extra preparations applied to the vineyard.
What type of fungal diseases is (Eutypa Dieback) aka dead arm?
Caused by Eutypa lata fungus.
Spores are caried by rain and enter the the vine trough pruning wounds.
it has drastic effect on yield, but not on the quality of the fruit.
What type of fungus diseases is Esca?
Thrives in warm climates, but exists worldwide, and there is no control or cure.
*Esca is result of a complex of fungi, rather than a single organism, on young vines will weaken growth, affect berries development and discolor the leaves.
- in older vines affects the wood, causing the trunk and arms to soften, and rot from the inside
What about Black Rot? (Fungal-Diseases)
*Native to North America, spread to Europe with the importation of Phylloxera-resistant rootstocks.
*Fungus originating as a black spot on the vine’s shoots, leaves & berries, can be controlled trough fungicides sprays.
What about Bunch Rot? (Fungal-Diseases)
*Caused by number of fungi species, reduce crop yields and may affect the character of the wine with moldy 0ff-flavors.
*Positive Bunch Rot (Botrytis Cinerea)
*Negative Bunch Rot (Gray Rot)
Pierce’s Disease? ( Bacterial Diseases)
Most commonly transmitted by the glassy-winged sharpshooter a leafhopping insect, causing the vines incapable of producing chlorophyll, killing it within one to five years.
Leafroll Virus? (Viral Diseases)
*Caused by at least 9 different viruses, may be responsible for as much as 60% of the world’s grape production losses, reducing yield and delaying ripening.
*Spread trough propagation of infected vines, or by insect like the mealy bug, but it will not kill the vine.
Fanleaf Degeneration? (Viral Diseases)
Spread by nematodes, feeding on infected roots, affected vineyards must be removed.
Flavescence Dorée? (Phytoplasma Diseases)
*First appeared in Armagnac in 1949, Leafhopper insects and propagation of infected vines spread the disease.
*Delay budbreak and slow shoot growth, causing bunches to fall of the vine and berries to shrivel, no cure exists.
