Seminar 2 Flashcards
What is the difference between species and cultivar?
Species is the larger group or family name. For this purpose, it’s Vitis Vinifera.
Cultivar = grape variety or the specific type of Vitis vinfiera. For example, Chardonnay, Pinot Noir.
How did the cultivar family develop?
Crossings and human intervention. The cultivar family grew over the course of centuries. Today there are 6000 - 7000 known cultivars.
Humans played a big role in the selection process
What species is cultivated in most wine producing countries?
Vitis Vinifera
How were vines reproduced in the past?
Through the process called layering.
Make a hole near the vine. Carefully bending the cane, bend it down into the hole. This cane will grow roots and have a life of its own. Eventually it will produce it’s own grapes. Vineyards with this type of propogration looked like a jungle.
Why was the layering method abandoned?
Phylloxera. Layering the cane under the soil made it easier for phylloxera to attack the roots. Vine would die after 3-4 years.
What is ampelography?
The study of vine, study of the shape of the vine.
What is the name of the organ which anchors and supports the vine (hint it winds around the wires) ?
Tendril
What is the name of the plant growth that develops from the rootstock of grated vines?
Sucker
What happens to the vines in the winter?
Become dormant, it’s a period of rest.
How do growers protect their vine stocks against the cold in winters?
A process called hilling up. Putting earth around the stock against the cold. As well as pre-pruning, leaving some canes in case of spring frost, hoping one survived.
What are the good and bad points of winter frost?
Good: As long as it doesn’t go below -15/-18 degrees Celsius, the plant goes dominate. Allows it rest. Also it’s antibacterical. Kills pests, bacteria, and larva.
Bad: Winter frost can be problematic and lead to serious consequences if temperatures reach extremely low levels (below -15 degrees Celsius) in a hurry or after a mild spell. This situation can be fatal for the vine stock and thus call into question several years of harvest. The vine is then frozen in depth leading to the death of the plant.
How do growers know that winter is over in their vineyards?
When you see sap at cane, also called Tears of the Vine. Once they see this they prune the vines with sharp and clean secateurs.
What are the weather conditions for bud burst?
Spring above 10 degrees Celsius. Usually in March.
What is the purpose of pre-pruning?
To leave some of the canes on in case of a spring frost, hoping one will survive.
What is the principle of Guyot pruning?
Original idea was to increase the yield.
Single guyot pruning: 1 cane, 5-7 buds
Double guyot pruning: 2 canes, 10-14 buds.
What do growers do with the canes they cut when pruning?
A few different things can happen. Shred, burn, or compost them. Now it’s suggested to collect them and turn them into fuel. Below are the problems associated with some of the methods.
1.) Cutting (shredding) many vines are infected. Problem with this is they are introductions bacteria into the soil.
2.) Burn them. Problem with this it pollutes the air. Since the canes are green, they create a lot of smoke and CO2 when burned.
What does plowing down consist of?
Plowing down is removing the earth around the stock that was placed there during the “hilling up” process. At this time the winegrower also irrigates the soil and weeds it.
What most a grower pay attention to when tying down?
Not to break the buds or the canes. It’s best to do in humid or rainy weather when the canes are more moldable. Classically this is “women’s work”.
Why is de-suckering a necessary task? How do growers do it?
Suckers keep growing, 1.5 m in a year. Once they lignify (become harden) you need sharper tools, easier to do when they are young.
What is the best weeding method?
By hand is the best method.
How do growers fight spring frost?
1.) Light barrel fires called bougies.
2.) Large fans
3.) Helicopters (not as common)
4.) Sprinklers, which help to keep the temperature above freezing.
Read more here: https://www.decanter.com/learn/winemakers-prevent-frost-ask-decanter-367606/
What is the pollinating agent of vines?
Vines are self-pollinating, a hermaphroditic plant. Wind/air carries pollen to help with this process.
Why is rain bad during flowering?
When a rain occurs during flowering, it can cause something called “stuck caps”.
The flower parts of a vine are contained inside a “cap”. These normally fall off at the start of flowering to reveal the reproductive parts of the flower.
Stuck caps can create issues in two ways…
1.) They can stop the fertilisation of that flower. If the flower isn’t fertilised then no berry is formed (so this can affect yield)
2.) A stuck cap is a source of infection for bunch rots (a group of diseases). The most common bunch rot is botrytis.
What is the name of the stage during which grapes take their shape?
Setting
