Viticulture Definitions Flashcards
(22 cards)
Extreme Heat
Above 95F, vines shut down
Drought Definition
Typical vine needs 250mm during the season to avoid stress
What makes a threat “Great”?
Breadth - how wide is the problem?
Depth - how bad is the problem?
- yield, quality, intensity of damage
Speed - how fast does the problem spread/ do damage
Solution -is there a known cure??
Detection - how easy is the problem to spot?
Red Blotch
VECTOR: three cornered alfalfa hopper
no known cure.
Leaves turn red, lose their ability to photosynthesize. Sugar production diminished – not able to attain brix higher than 21-23 Brix.
Red blotch interferes with secondary metabolism responsible for flavor precursors. Phenolic maturity slows down color & mouthfeel components difficult to attain. In early days days of the virus, hangtime can fix this but not later!
Red blotch was disccovered in the US.
symptoms more pronounced in red varieties
Pierce’s
Flavescence Dorée
Examples of Fungal Diseases
Downy
Powdery
Grey Mold/Botrytis Cinera
Trunk Diseases
Examples of Viral Diseases
Fanleaf
Leafroll
Red Blotch
Example of Bacterial Disease
Flavescence Dorée
Powdery Mildew
(OIDIUM)
odium - podium - powdery no H20
- Airborne, germinates under dry conditions!
Threatens Yield and Quality - causes berries to split!
Reduces berry sugar levels, juice color & acidity
Chardonnay is more susceptible than PN
Breadth: - GPM management has been estimated to cost as much as 37% of the gross value of production in places where GPM pressure is significant (references PNW)
Prevention
- PM hates UV sunlight - leave more exposure to sun in canopy
- Treatments:
– sulfur in wettable formula: spray weekly during peak
– KMS - potassium metabisulfite
– HML32 Potassium based liquid soap applied w/ copper fungicide (organic)
EXAMPLES: Root Applied Sciences, air monitoring early detection service. detects 2 weeks in advance. Ridge in Santa Cruz Mountains said saves 2 sprays a year - typically 10 sprays so 20% case savings.
Chandon de Briailles
started experimenting w/ skim milk to prevent oidium in 2013; now approved by EU as of 2020
biodynamic as of 2005
also used by Chantreves
was in a book about growing vegetables (rather than in a viticulture book)
work with a local farm - was a discarded product for the farm
started with milk + sulfur and just skim milk – milk worked just as well as the one combined with sulfur
no sulfur that comes from petro chemicals
- no need to take a break after spraying ; no irritation
- photosynthesis works better
no problems with reduction
- lactoperoxidase- creates free radicals with sunshine
lactoferrin -
preventative & curative
need to spray with 10-20% of milk in solution
is contact product, must be sprayed on all the leaves (good coverage)
still have sulfur as a solution for use if needed
Brett brothers have been experimenting with whey
Chandon de Briailles
4 hours to farm 11 ha
Downy Mildew
YELLOW SPOTS ON LEAVES; feathery patches on undercide only!
kills leaves, no photosynthesis
WARM WET NIGHTS
more aggressive than powdery.
Problem ESPECIALLY in Europe
Bordeaux mixture - copper + sulfite
infection near flowing can lead to total crop loss
Lanson - normal yields are 12,000kg/ha, in 2021, got 1,000 kg/ha
ESCA
“ESCA COMPLEX” grouping of different fungal trunk diseases, thus manfiests differently
BLACK GOO! fills vascular tissues; prevents nutrients from forming. starves the vine, causes vie death/necrosis
warm/wet conditions - airborne spores affect deadwood during rainfall
infection through pruning
has similar symptoms as other conditions (salt toxicity, frost damage etc.) so hard to tell what the problem is
EUTYPA
BLACK PYRAMID - TRIANGLE DEATH (EUTYPA DIEBACK)
“Eutypa lata” - responsible fungal species
Can take several years after infections for symptoms to show
Caused by extend of pruning woods!
Remove diseased wood - “curetage,” vine dentristy
Treat Pruning Wounds
Example:
Eutypa, big issue in Martinborough. Can graft new vine onto the unaffected part of the trunk to try to save the vine. Dry River rootstock 5BB - 46 year old root stystem. Graft has a shortcut to a large feeder system, w immediate nturient and mineral.
Leaf roll
Leafroll lowers sugar content of grapes – growers are paid based on tonnge and sugar content. no cure, can replant vines to slow spread.
Prevention: sexual confusion; mating disruption
Kistler uses 3309 rootstock as it shows leafroll resistance (in addition to drought resistance)
“Grape mealybug management is ranked as the number one issue for wine grape growers in Washington,”
Yield
Measurement of grape production
weight / unit of land
- pounds / ton
weight of grapes per vine
kg
volume of liquid / unit area of land
WHY DOES IT MATTER?
- quality & REVENUE
less fruit rate of sugar accumulation increases for the fruit that remains
Yield conversions!
ton/acre -> hL/ha
1 American ton /acre = 15 hL/ha (white wine)
1 American ton / acre = 19 hL/hared wine
—> to turn hL/ha into tons/acre divide by 15 or 19
100 L red wine = 130kg grapes
At planting density of 10,000 plants /ha
45 hL/ha = 0.45 L per vine
At planting density of 6,000 plants / ha
35/hL/ha = 0.58 L /vine
1 ha = 2.5 acre
1 ton grapes = 700 L
(more for white grapes than red)
4500 kg/ha –> 45 hL/ha
10,000 kg/ha = 64 hL/ha in champagne
Yields
Style:
* Chateau d’Yquem- 8 hl/ha
* Royal Tokaji – 10 hl/ha
* Champagne- 2022 the upper cap was 16,500 kg/ha or 105 hl/ha
* Sherry- 80 hl/ha Jerez Superior and 100 hl/ha elsewhere (but can reach 150 hl/ha)
Climate (Hot vs Wet)
* Symington Douro Port – 25 hl/ha (< 1.5 ton/acre) - 300mm annual rain per year
* South Australia – 2 tonnes/ha or 15-30 hl/ha – 300 - 400mm annual rain per year
* Southern Bell Murcia Jumilla – 10-20hl/ha- 300mm annual rain per year
* Priorat – 10 hl/ha – Avg 2,350 /ha (range from 2,500- 9,000) - 400-600mm annual rain per year
* Rias Baixas – 50 hl/ha – 84 hl/ha (max) (Average is about 64 hl/ha) – 1000-1500 vines/ha – 1600 mm annual rain per year
Regulation (maximum)
* Champagne- 2022 the upper cap was 16,500 kg/ha or 105 hl/ha
* Bordeaux AC- 55 hl/ha St. Emilion Grand Cru 40 hl/ha
* Soave – 140 hl/ha
* Beaujolais – 50 hl/ha
* Rheingau - 84 hl/ha
Cade Winery 15/hL /ha in howell mountain
central valley is 100-200 hL/ha
planting density conversion
10,000 vines / ha
1 meter x 3 meter
this is the highest density commonly found!
1 degree of latitude in miles
70 miles
altitude & temp relatinoship
1 degree celsius cooler, per 180m gained ~200m)
