Element One, Varietal Selection, Propagation and Tolerance to bad stuff Flashcards
Main criteria when selecting Vines? (4)
Adaption to the Climate
Resistance to disease
Adaptation to soil conditions
Economic characteristics
Nurseries developed a large numer of hybrid rootstock by crossing V Berlandieri with V Riparia and V Rupestris, why?
Riparia and Rupestris have poor calcium tolerance, (European Soil) and Berlandieri and high but dont graft or root well from cuttings.
Late 1950 hybrid occupided 30% of french vineyard area, why?
Downy mildew resistant hybrids was put in.
What hybrid is still today used in germany and the sixth most planted red variety?
Regent
what do mass selection or “selection massale” do?
before harvest, marking out the best plants to take cuttings from during the winter. Or Eliminating plants instead of selecting them.
Clonal selection started in? (Country)
Germany on Silvaner
The criteria for clonal Selection is? (7)
- Yield
- Sugar concentration and must acidity when ripe
- Quality of phenolic and aroma content
- Resistance to disease, drought, cold ect
- freedom from viral infection - fan leaf, leaf roll, vein necrosis, corky bark and stem pitting
- ease to grafting
- Cost
Disadvantages in clonal selection? (4)
Closely related - spread of disease
Specialised and only suitable for some regions
Increase in yield and overproduction
reduction of the vines genetic resources
Vines are not often planted as seeds - why?
propagation from cuttings is quicker and easier. and allow grafting to Phy-resistant root.
when taking hardwood cuttings, what is important? (2)
Collected in autumn or winter, high levels of carbohydrate reservs.
Wood to be well-ripened and healthy, green cell layers and full of sap.
Cuttings, how long when taken and stored, what about pests?
30 - 40 cm and stored in 5°c, heat up in 50°c for 30 min to kill pests.
The cutting needs to grow successfully and why? (3)
Plenty of water, as the leaves grow faster the the roots.
Warmth, temp at 15-25°c are best.
Loose, well-drained soil. High water holding, good drainage and protection from the vine weevils.
Field-grafting is abandoned in favour of bench grafting, why?
indoors during winter, and machine not by hand as before
How is Bench Grafting done?
Done in doors during winter, stored in damp sawdust.
Soaked for 24-48 h, scion dipped in paraffin wax to just below graft union to stop it from drying out.
High humidity 90% with good drainage and a temp at 21-29°c for 3-5 weeks. The Scion and Rootstock will now join together, re-dipped in paraffin and kept cold 1-4°c prior to planting. Planted and keep at 18-21°c for 7-10 days.
Grafted rooted cuttings are sold as?
Rooted cutting, One season in a vine nursery.
Or as potted plants, Greenhouse and can be planted out within 10months of grafting.
What is chip-budding and T-budding?
Where a bud from a new varietal is inserted on to the trunk of the old one.
What is Cleft-grafting?
Sawing the trunk of the vine and inserting canes of the new variety into the cleft.
Where works Cleft-grafting well?
on young vines in warm climates, need well aftercare of the plants..
What are the symptoms of an Phylloxera infestation? (4)
- Vines die of drought in patches that grow in size every year.
- the roots are infected and covered in insects, yellow-brown and lemon-yellow eggs.
- Nodosities (white or yellow) near the root tip on young vines and swelling on older roots.
- pale green leaf galls on the under-surface of the leaves.
What is the difference between how the nematodes species “Pratylenchus and Melodogyne” and “Xiphinema” effect the vine?
Pratylenchus and Melodogyne - damage by fedding off the roots
Xiphinema - tansmit viral diseases.
What is the best way to get a resistant American rootstock to function in lime soils?
Crossing V Riparia/V Rupestris and V Berlandieri to a hybrid and sufficiently resistant to avoid chlorosis
Excess acidity can give problems to rootstocks, what?
Aluminium toxicity
High levels of salinity can give problems to rootstocks, what?
Disrupt water uptake and vine nutrition
What rootstocks is best used in damp conditions?
Vitis Riparia
