Level 4 Viti Flashcards
Define a Low Vigour site What planting density should be used? What type of trellising?
<0.5m deep, limited water in growing season, low fertility Hi Density >5k plants/ha (unless where water very limited) VSP with single or double guyot
At what temp is a vine dormant?
<10c
How thick, how long should shoots be?
Pencil thick 12~15 nodes long
What rootstock might you use in areas with very cold Winters?
Vitis Amurensis
What element is shot into the sky to disperse hail? What else protects against hail?
Silver Iodide Towers charged with static electricity Netting Site diversification
What temp is considered too cold for grape growing
One that is below -20c more than once every 20yrs Or Has a mean temp <1c for the coldest month
What are the 4 stages of Berry growth / ripening?
Herbaceous phase Veraison Maturation Sur-Maturation
What is ‘Floral Initiation’?
Where embryonic flowers develop in the dormant bud the year preceding budburst
What planting density for Poor soil?
High density
What is preparation 501?
Horn Silica, fine ground Silica buried in cow horn over the Summer. Sprayed on vines 2~4 times a year. Supposed to improve photosynthesis
What are Anthocyanins and where, in the grape, are they found?
Provide red wine colour, found immediately beneath grape skin (Peripheral Pulp)
What factors increase / decrease water requirements in the growing season?
Vine density, soil water holding capacity, time of rainfall, wind
A sandy soil in a high rainfall area is likely to be deficient in which nutrients?
Potassium, Calcium, Sulphur
What is a really good rootstock to use where the soil is dry and stony and prone to drought?
110R Richter
Which rootstock performs best in saline soils?
1103P Paulsen
What are the symptoms of Downy Mildew (Peronospora)? How does it like to grow? How is it treated?
Fungus. Lives in (not on) vine tissue. Damages green part of vine esp. young leaves. Yellow oil spots on surface of leaf w white downy patches underside. Needs rainfall/water and warm temps. Highest risk years are rainy Winters, Springs and stormy/warm Summers Control canopy management to avoid leaf bunching Spray Bdx mix (Lime and Copper Sulphate) every 20mm rain, 15~20cm growth, 10~14 days
How are Cordon de Royat, GDC and Sylvoz normally pruned?
Cordon / Spur pruned
Your vine has stunted shoots with small yellow cupped leaves, the grapes are OK but yield is substantially decreased. What is the disease and how did it occur?
Eutypa dieback / Dead Arm / Dying arm Fungus entered pruning wounds
Who original proposed the concept of Biodynamic farming?
Rudolf Steiner
What are the symptoms of Leafroll Virus? How does it like to grow? How is it treated?
Symptoms seen in Autumn; red (black grapes) and yellow (white grapes) leaves with downward rolled edges. Reduce yield -50%. Sugar -30%, delay maturity 4 weeks. Wines made less colour, alcohol, flavour and body Disease spread by planting infected cuttings and vines Mealybugs a poss vector in S. Africa No cure! Dig up vineyard and re-plant
What are three key elements of a vineyard site assessment?
Soil profile Water supply Soil fertility
What is the main effect of Canopy Management?
Affects the climate in the fruiting zone, therefore style and quality of wines
What is the difference between ‘Prompt’ and ‘Latent’ buds?
A Prompt bud breaks in the same year A latent bud breaks the following Spring
What 4 things can affect the chemical composition of a grape?
Grape variety Climate and soil (terroir) Viticultural management Seasonal / weather variations