past exam questions Flashcards
A) How is pruning level quantified?
B) Give quantitative levels of severe and light pruning.
C) What are some of the shoot characteristics of severely pruned vines compared to those lightly pruned?
Explain what is meant by yield component compensation?
Question 3. (20 marks)
A) Quantified as the number of nodes left after pruning.
May be expressed as nodes/vine, nodes per metre of row, nodes per metre of canopy, node/unit area of vineyard surface.
B)
- Severe pruning: less than 20 nodes per metre of row
- Moderate: 20 - 75 nodes per metre of row
- Light: greater than 75 nodes per metre of row.
C)
Severly pruned vines, Bare hardly any nodes or buds at all. this pic was on a spur pruned vine
Lightly pruned, Looks like a birds nest with stuff going everywhere. doesnt look likt it will be very well balanced.
Yield component compensation :
level of one component is offset by level of another eg. more nodes left: decrease in shoots/node, berries/bunch and weight/berry ( see next lecture on minimal pruning )
is 3.6 x 2.4 m and it is hedge pruned by machine with a single wire trellis. The typical irrigation amount is 6 ML/ha applied from budburst to harvest by drip. My average yield is 35 t/ha. However, the winery to which I sell my fruit has told me that, unless I reduce m y yield to 25 t/ha or less in future, they will no longer take my fruit. I can’t afford to shoot thin nor do any bunch removal.
a) As my consultant, what do you suggest is the most cost - effective means by which I can reduce my yield to the required level ?
b) Provide me with very precise instructions to achieve this end result.
c) Is there likely to be an improvement in the end - use rating of the fruit and, if so, what is the likely explanation?
(20 Marks)
Summer pruning (trimming slashing): a canopy management tool for improved fruit composition and disease control, used in hotter districts to delay fruit maturation to improve composition (flavour and aroma), but reduces yield by 50 - 60%.
Vegetative cycle: canopies tend to become more shaded and vegetative; yield and quality reduction.
Please discuss the following statement (20 marks)
a) “Bird netting is the best form of bird control in the vineyard”
Netting
• the most effective method but requires careful cost:benefit analysis to ensure it is an economic solution
• Lockout or canopy netting
– Netting, pole caps, staples = $5,000/ha
Approximate cost per ha
– Netting life 5 years = $1000/yr
– Application & removal of net = $1000/yr
TOTAL COST per ha per yr = $2000
Please discus the following statement (20 Marks)
“Alternative varieties are the future of the Australian wine industry”
- Missing an opportunity to develop greater regional distinctiveness
- Better suited to climatic conditions than existing varieties in terms of heat and drought tolerance
- Greater range of flavours eg Asian market
- Better suited to particular wine styles
- White wines with texture
- Can produce low alcohol wines
- Better droubt tolorence
- Better disease tollorence, tougher skins and looser bunches
- Traditional winemaking practices in region of origin may not allow full potential of variety to be expressed
- requires a broad assessment and marketing plan
- takes significant time, effort and money
- winemaking method may be as important as getting the viticulture right
- egskin contact for whites?
- single variety wines are normal for initial evaluation
- but blending may be the norm in region of origin
- May be difficult to get exposure to consumers
Examples for alternative white varieties
- Fiano
- Gruner Veltliner
- Verdejo
- Vermentino
Alternatives for red varieties
- Aglicnico
- Lagrein
- Montepulciano
- Negro Amaro
- Nero d’Avola
On our visit to Yangarra we observed a biodynamic vineyard management system. What was the significant emphasis on soil, canopy, and floor management as a basis of their production system? Out line how the vineyards were managed listing both the positive and/or negative aspects of this approach to vine production relative to conventional management.
(20 Marks)
Boi-dynamics
Considers the vineyard as a ‘holistic’ farming system which includes a connection to the cosmos.Strict adherence to standardsand inspection and must apply to government regulations.Cannot use synthetic products
Precieved advantages of going organic
- grape and wine quality
- marketing
- personal health and safety
- agricultural and environmental sustainability
Two biggest problems
- Inadequate weed management
- Reduced yields
Describe the difference between minimal and mechanical pruning.
List some advantages of minimal pruning?
Why is minimal pruning not suited to all varieties?
What varietal and trellis considerations are needed for mechanical pruning?
(20 Marks)
Minimal pruned vines
- Trend to lighter pruning in many areas has come about for several reasons:
- Increased yield with significant decrease in hand pruning costs.
- Hard pruned vines are not more drought tolerant.
- To achieve maximal response to irrigation, necessary to prune more lightly.
- Higher yield, better quality fruit, reduced costs.
- Less bunch rot due to looser bunches, smaller berries.
- Bunches tend to be more uniformly distributed, nearer to the canopy exterior.
- The grapevine has a great capacity for self regulation
- Pruning does not have as much effect on yield restriction as previously thought (see last lecture, Winkler’s data)
- Minimally pruned vines out - yield trad pruning, but varies with region, season and variety, eg good with Sultana (trad cane pruned), good with Sauvignon blanc in cool climates.
- Minimal pruning relies on vine - self regulation:
- Node number per cane is reduced naturally by abscission of terminal shoot.
- Leaf area much larger in first month after bud - burst.
- More shoots and bunches
- Smaller bunches and berries
Mechanical pruning
- Refers to cutting canes (hedging back to spurs) to required spur length (usually 5 - 40 cm above cordon) with hand clean - up.
- Mechanical pruning estimated 60% of cultivated vine area in Aus. (mechanical harvesting 90%).
- Much reduced cost compared to hand pruning
- Hand clean - up performed each year to regulate node number more carefully if necessary and reduce accumulation of old and dead wood, downward facing and outward pointing canes.
- More naturally upright vines are more suited to mech. pruning: Cabernet Sauvignon, Cabernet Franc and Semillon.
- VSP easiest to prune mechanically because it is easier to see where to position cutting blades to get spur length.
- Dense wood around fruiting zone requires more aeration by vertical shoot positioning.
- Cuts to two year old wood can make vine susceptible to Eutypa.
Results: similar to minimal pruning
- Bearer length is not constant (0 - 6 nodes), important to maintain constant height to maintain same spur length each year, prevents long shanks.
- More nodes are left.
- Generally longer bearers lead to increased bunches per shoot (distal nodes are more fruitful than basal).
- After initial increase in yield, it usually decreases through 2nd and 3rd years.
- No direct correlation with wine quality.
- As per MP higher yields in cooler areas can produce ripening problems.
- Trellises need to be designed with mechanisation in mind, as well as product specifications.
- Identify and describe two methods by which grapevines are commercially or traditionally propagated.
For each describe the basic physiological parameters required for successful propagation of grapevine tissues and why they are important to the process. (6 marks)
- We discussed many propagation techniques that can be used to change varieties and or rootstocks in a selected vineyard. As a person in charge of a large commercial vineyard you have been asked to convert a 10 Ha vineyard from one variety to another. Which approach would you take and sell to the owne rs of the company? Please justify your answer. (9 marks)
Types of propagation
1. Seeds - only in breeding
- – Sexual reproduction will change the phenotype
- – Time period
- – Limited recurrent hybridisation
2. Hardwood cuttings / rootlings
- own - rooted vines, rootstock/scion)
• Selection
- Appearance
- Mother vine health and nutrition
Cutting specifications
- Own - rooted canes:
- 8 - 12 mm diameter medium length internodes
- For bench grafting:
- Straight, 7 - 10 mm diameter
Taking cutting
- Scion wood: 30 - 40 cm long
- Rootstock wood: 40 - 45 cm
Timing
- In theory, cuttings can be taken any time after leaf fall and planted directly in field
- For some rootstock varieties, e.g. Ramsey, best to take as soon as possible after leaf fall when starch (CHO) content is highest
Treatments
– Hydration
– Fungicide treatment
- protects against Botrytis
- usually only for cool room storage
- Available products:
- Vibrex flora (Chlorine dioxide)
- broad spectrum bacterialcide, fungicide, algaecide
- 2 mg/L sodium hypochlorite (1 - 5 days)
- Chinasol (banned in Australia)
- Benlate (0.1%)
- Hydration (dilution of fungicide)
Storage
- Open - nursery (in ground)
- Sand bed (completely covered, hydrated, well drained)
- Cool room
- 1 – 2 ° C better than 4 - 5 ° C
- Re - hydrate often (keep sealed)
- Dark
- Plant within 48 hrs
Callusing cuttings
- Callus development - need (H 2 O, air, heat)
- Field versus Indoor
- Field allows several batches per season, each taking only a few months
- Indoors can use shorter cuttings than in an open nursery (less wood)
- e.g. as short as 2 nodes
- Indoors can start in winter
3. Softwood cuttings (as for hardwood)
4. Layering
- – replacement of missing vines
5. Grafting and budding
- change scion of existing vine (top - grafting or top - working)
- resistant rootstocks
- Grafting is the process of joining parts of plants together so that they will unite and grow as a single plant (many methods).
- Scion, rootstock, union
- Budding is used when the scion comprises a single bud plus a small piece of stem.
Grafting and budding are techniques used for:
- Resistant rootstocks
- Change varietal mix of the vineyard
- Eliminating pathogens
- And may be used before and after vineyard establishment
Risk assessment is critical for both
- Does the benefit outweigh the cost?
Question 4 . ( 1 0 marks)
Why is vineyard monitoring important when managing a vineyard
Please discuss the followin statement;
a) “Organic and biodynam ic vineyard practices are more sustainable than conventional vineyard practices ” (20 marks)
Sustainable practices are based on farming that is not only good for the environment, but also makes economic sense. This means that a farmer may largely use organic practices, but if some of those practices don’t make economic sense (eg – they’re too expensive), the farmer might skip some of them. Just as with biodynamic wine, there is no formal certification for a wine to be sustainable, but there are several associations that winemakers can join to formally list themselves as a sustainable vineyard.
Please discuss the following statement
b) “Grape growing in the Riverland is unsustainable” (20 marks)
Riverland growers should enjoy some much-needed relief this season thanks to small increases in the price of both red and white wine grapes.
Heightened demand for Australian grapes due to a range of domestic and international factors has seen prices improve by 17 per cent for red grapes and 7 per cent for white grapes.
It comes after years of hardship for growers who have struggled to stay afloat amid oversupply and poor grape prices.
“We’ve been very pleased this year that the pricing sequence since mid-December has been very positive,” Riverland Wine executive director Chris Byrne said.
Why is it important to understand the nature of damage a bird can cause in the vineyard? In your answer provide examples of the types of damage that can occur.
Question 6 (10 marks)
Pecking
plucking
biting squashing or tearing
You are planning to plant a vineyard in the Adelaide Hills in spring 20 17 . You have owned the land for several years and the potential site is c urrently used for grazing sheep. There is an existing small dam which you intend to enlarge for the purpose of vineyard irrigation. A soil survey of the intended site has been completed.
The house of your nearest neighbour is 100 m from the potential viney ard boundary. List the six most important actions that you should now take before the end of 2015 .
Question 7 (10 marks)
Principles of Biodynamic viticulture
- Holistic approach based on teachings of the Austrian philosopher Rudolf Steiner in the 1920s.
- Holistic management approach that incorporates the integration of crops, livestock, soil and the health of the farmer
- Strong association with spiritual science:
- Acknowledge the influence of cosmic and terrestrial forces
- Enrich all on the farm with life’s energy
- Biological - organic practices
- Dynamic
Growing vines Bio-dynamically
- Uses the philosophy of organic farming but goes beyond this
- Considers the balance of the ecosystem and its connection to the cosmos
- Avoids raw manures but incorporates ‘preparations’ to compost; improves nutrient cycling
- Emphasis on soil fertility and humus effect
- Emphasis on ‘Bio’ (Greek) - life
Key Inputs
- Incorporation of compost
- Spray 500 (Horn Manure)
- Spray 501 (Horn Silica)
- Production of the preparations (502 - 507)
- Lunar cycle
- Biodiversity
Certification process
- Contact & application
- Questionnaire
- Inspection
- Application review
- Contract
