what type of disease is botrytis and what are the effects?
fungal disease can be good for fully ripening grapes or bad on ripening grapes and can cause gray rot
what are the two most damaging fungal diseases?
powder mildew-also known as oidium
downey mildew-also known as perenospera
describe fungal diseases
spread by airborne spores and are an issue with warm humid conditions which are ideal for fungus
describe pierces disease
bacteriological contamination of host vine causing premature leaf fall. Can be spread by sharpshooters (glassy winged sharpshooter) or leaf hoppers
describe continental climate
far from ocean effects, hot summers and colder winters. Sometimes experiences less rain that maritime
describe Mediterranean climate
warm dry summers, mild wet winters and low humidity. Short summer growing seasons not good for grape growing
(abnormal fruit set) grape bunches that have a high proportion of small seedless grapes to normal seed bearing grapes caused by bad weather
at what age are most commercial vines dug up?
25-30 years however old vines 20-100 years can produce great quality
a newly planted or grafted vine will produce grapes in what year?
1-2 years but are substandard and generally removed to allow vine to focus on trunk and roots
what is field grafting?
cutting a small incision of the trunk and inserting an uprooted cutting from a desired vine in another vineyard
true or false? The warmer it is the faster the plant respires and the quicker the acid levels drop, cool nights are beneficial for ripening grapes
true because it minimizes acid loss when photosynthesis is occuring
what are two key components to a vines metabolic process?
photosynthesis-green leaves produce sugar from sun
respiration-opposite of photosynthesis sugar and chemicals are broken down to produce energy for roots and leaves
are vitis vinifera self propagating?
yes pollen is blown by wind to polinate a flower which then develops a seed
clone vs field selection
clone is taken from a single plant
field selection is taken from many vines
a vine that develops different characteristics than its parents or fellow clones, pinot blanc and pinot gris a mutants of pinot noir
what notable character do north american vines have over vinifera?
natural resistance to phylloxera root louse
* growers learned vinifera shoots could be grafted on American trunks to get resistant vines
what is the second type of grape species used commercially typical of North America?
labrusca produces well known concord grape, sweet but not good for wine because of its foxy character
define cross or crossing
offspring of sexual reproduction of different subspecies within the same species. Cabernet sauvignon is a cross between cab franc and sauvignon blanc
offspring of sexual reproduction between two closely related species such as vinifera and labrusca
is there a certification necessary for biodynamic growing?
yes through a private company called demeter international
what is the unit of measurement used in France to measure alcohol
baume milimeters / 100 millimeters of wine
what is the measurement used in germany to measure alcohol?
oechsie (density of grape must-1.0) x 1000
define guyot trainning
each vine is trained along a wire single guyot in one direction double guyot in 2 directions
define head training or bush training
no trellis used and the vine grows like a bush or a miniature tree
what was the cause of Europe's vine devastation and what was the remedy?
phyloxera they grafted american rootstock to the plants