Grape growing options Flashcards
What are the three advantages of conventional viticulture (i.e., monoculture)?
- Mechanization (decrease labor costs)
- Reduction of competition from other plants
- Ability to optimize for the specific variety, increasing yields while minimizing costs. Optimization would include:
a. Irrigation
b. Nutrition level
c. Treatments against hazards, pests, and diseases
- Ability to optimize for the specific variety, increasing yields while minimizing costs. Optimization would include:
What are the three disadvantages of conventional viticulture (i.e., monoculture)?
- Plants are much more prone to disease and pests (due to uniformity), and thus need more treatments or protection
- Nutrients can be depleted as there is no natural ecosystem to replenish nutrients, requiring more applications of fertilizer
- Residual chemicals can contaminate groundwater or air
What is the overall approach of sustainable viticulture?
Develop and in-depth understanding of the vineyard to predict and prevent a pest or disease before it occurs, and to time applications to when they will have maximum effect, to minimize treatments.
What are the four steps of integrated pest management (IPM)?
a. Setting thresholds at which action needs to be taken
b. Identifying and monitoring pests
c. Setting up preventative measures
d. Evaluating and implementing control options (if thresholds are exceeded and preventative measures are not effective)
What are the four advantages of sustainable viticulture?
- A more thoughtful approach, with attention to the economic, social, and environmental impact
- Minimize interventions needed through scientific understanding of pests and diseases
- Reduction of synthetic and traditional treatments
- Cost savings
What are the two disadvantages of sustainable viticulture?
- Term is not protected and therefore can be used without a set standard
- National rules may be set too low (e.g., in NZ, virtually all commercial growers)
What are the 4 key features of organic viticulture?
- Application of compost: slow release of nutrients, improve soil structure, and biomass in soil
- Natural fertilizers (animal dung, natural calcium carbonate, etc.): restore natural balance in vineyard
- Cover crops: prevent erosion and contribute to improvement of vineyard ecosystem (e.g., by ploughing in (“green manure”))
- Reduction of monoculture: growing cover crops, planting hedges, and establishing islands of biodiversity
What are the 4 advantages of organic viticulture?
- Better vine health and disease resistance
- Better soil heath
- No spraying of synthetic chemicals
- Cost savings in not having to buy synthetic chemicals
What are the disadvantages of organic viticulture?
- Possibly small reduction in yield generally
- Possibly significant reductions in yield in difficult years (e.g., long periods of rainfall or high humidity)
- Increased reliance on copper sprays, which may lead to buildup of copper in soils
- Cost and time in seeking certification [and possibly higher labor costs, which vary based on location]
What is biodynamic preparation 500 (horn manure) and what is it said to do?
a. Stuffing cow manure into a cow’s horn, burying it in winter, then dynamized (stirring in water, first one way then the other–the water “memorizes the power of the preparation so it can pass it to the vineyard”), then sprayed onto the soil as compost.
b. Said to catalyze humus formation.
What is biodynamic preparation 501 (horn silica) and what is it said to do?
a. Fill cow’s horn with ground quartz (silica), burying for 6 months, then dynamized and sprayed onto soil.
b. Said to encourage plant growth.
What are the advantages/disadvantages of biodynamic viticulture?
- Similar to organic (limited research comparing the two)
What are the 4 key features of regenerative viticulture?
- Restore a vineyard site to a functioning agroecosystem (ecosystem modified for agriculture) to improve resources and limit inputs
- Soil health is top priority, as it will improve the health of the entire vineyard
- Biodiversity (above and below ground) is essential (e.g., encouraging organisms with symbiotic relationships, like mycorrhizal fungi)
- Grape growers improve their well-being by reducing the cost of synthetic inputs and limiting exposure to harsh chemicals
What are 4 common practices of regenerative viticulture?
- Limit tilling (which sequesters carbon, among other things) and limit irrigation
- Add compost to increase organic matter in the soil and replace nutrients
- Cover crops to prevent erosion and reduce water loss
- Animals (like predators) can create natural controls for pests
What are 5 advantages of regenerative viticulture?
- Soils rehabilitated, decreasing need for synthetic inputs
- Carbon sequestered
- Vineyards become more resilient (limiting effects of climate change)
- Biodiversity improves along with animal welfare
- Lives of grape growers improve through less exposure to harmful chemicals
What are 5 disadvantages of regenerative viticulture?
- Not legally defined, so claims may be exaggerated
- Growers need to experiment with what works in their vineyard, which takes time and resources
- Once a plan is established, results take time, which is difficult and costly
- Producers can’t rely on inputs in case of disease or climate issues, which may reduce yields
- Certification costs
What is the goal of precision viticulture?
The goal is for all key interventions (like pruning, leaf removal, treatments, irrigation, crop thinning and harvesting) to be tailored to small plots, increasing quality and yield and reducing treatments.
* Examples: Changing rootstocks halfway along rows as soil fertility increases, or increasing leaf-stripping in areas of high vigor
What are 2 advantages of precision viticulture?
- Detailed understanding of variations between and within vineyards
- Variable-rate application technology: Ability to tailor a wide range of interventions (choice of variety and rootstock, canopy management, treatments, harvest dates) to individual blocks or even rows of vines, with the aim of improving yields and/or quality
What are 2 disadvantages of precision viticulture?
- Initial cost of remote data collection
- Cost of sensors and software and of consultants or trained staff to interpret the data and make interventions based on it.
Who practices precision viticulture?
Considerable upfront costs means that it is only an option on large scale viticulture or high-value smaller estates (and in practice mostly in CA and Australia)
What are the 6 key aims of canopy management?
a. Maximize the effectiveness of light interception by the vine canopy
b. Reduce shade within the canopy
c. Ensure the microclimate for the grapes is as uniform as possible so they ripen evenly
d. Promote balance between vegetative and reproductive functions of the vine
e. Arrange vine canopy to ease mechanization and/or manual labor
f. Promote air circulation to reduce disease pressure
What 6 factors does the yield that represents a balanced yield (with respect to vegetative vs. reproductive functions) depend on?
- Climate (warmer/sunnier/wetter can ripen more grapes)
- Variety (Cab Sauv will ripen a larger yield than Merlot)
- Rootstock
- Disease
- Vine age
- Style of wine (grapes for rosés can have less ripe tannins)
What are the two extremes that are to be avoided in achieving a balanced yield?
i. Avoid a vegetative cycle (where too much shade of buds results in lower yields the next year, possibly leading to under-cropping)
ii. Avoid over-cropping, where not enough carbohydrates are stored in the truck, cordons, and roots, which weakens the vine in future years
What are 6 effects of promoting sunlight exposure to grapes?
a. increased sugar levels in grapes through increased photosynthesis in the vine
b. increased tannin levels and greater polymerisation, leading to less bitterness
c. more anthocyanin (color) development in black grapes
d. decreased malic acid (due to greater respiration and thus metabolism of malic acid)
e. increased levels of some good aroma precursors and aroma compounds (such as terpenes)
f. decreased methoxypyrazines
What are 6 ways in which varieties (or clones) can be more or less well adapted to a cimate?
- Time of budding (e.g., early budding more at risk of frost)
- Duration of annual lifecycle (e.g., early ripening better for cool; late-ripening better for warm/hot)
- Tolerance of drought
- Resistance to disease (e.g., Cab Sauv less prone to grey rot than Merlot)
- Winter hardiness
- Vigor (e.g., Sauv Blanc on fertile soils with water requires vigor management)
Other then climatic factors, what are 6 other consideration in choice of variety/clone?
- Style of wine
- Yield (aiming for inexpensive, pick high yielding varieties/clones)
- Cost (some varieties, like Pinot Noir, are more difficult/expensive to grow)
- Law (e.g., EU regulations)
- Availability (perhaps limited by high demand or lack of supply)
- Market demand (demand for wine (accounting for fashion) and route to market)
What are the 4 criteria for selecting rootstocks?
- Resistance to pests
- Water (tolerant of drought, water-logged soil, or salinity)
- Soil pH (high or low)
- Vigor (high or low)
How can rootstocks be better suited to differences in water?
i. Tolerance of drought because of deep/quick rooting: hybrids of V. rupestris and V. berlandieri, such as 110R or 140R
ii. Tolerance of water-logged soil: based on V. riparia, such as Riparia Gloire
iii. Tolerance of salinity: based V. berlandieri, like 1103P
What are examples of rootstocks suited to different soil pHs?
i. Low pH: 99R and 110R, both hybrids of V. rupestris and V. berlandieri
ii. High pH: based on V. berlandieri, such as 41B
What are examples of rootstocks suited to different vigors and why one would want them?
i. Low vigor (can advance grape ripening in cool climates): based on V. riparia, such as 420A and 3309C
ii. High vigor (can boost vine growth and yields in unfertile and dry soils, or use for sparkling wine aiming for delicate aromas and high acid): based on V. rupestris, such as 140R
What is the one advantage and two disadvantages of clonal selection?
- Advantages
a. If all vines grow in a similar way and fruit ripens at the same time, may be simpler - Disadvantages
a. Perhaps less diversity of fruit, and thus less complexity
b. Perhaps equally susceptible to disease or pest
What are the 2 advantages and 2 disadvantages of mass selection?
- Advantages
a. Increases diversity in the vineyard and larger region
b. Vineyard owner uses their own material, which can enhance quality or yield at their site (and used for marketing) - Disadvantages
a. Selecting and monitoring vines takes work
b. If parent vine is infected by disease, it will likely be passed to the new vines
What is mass selection?
A vineyard owner takes cuttings from their own best-performing vines and cultivate them (perhaps sending to a nursery for grafting).
What is soil health and what 4 factors contribute to it?
Capacity of soil to act as living ecosystem. Related to:
* Structure of soil (good drainage, water-holding capacity, sufficient oxygen, erosion resistance, root penetration)
* Amount of organic matter and humus in soil (improves structure and water-holding capacity)
* Number of living organisms in soil (like earthworms and microbes that break down organic matter into humus and inorganic nutrients)
* Total amount of available nutrients
What are 6 primary interventions with respect to nutrient management?
- Fertilizers
- Cultivation (plow soil to disturb weeds’ roots)
- Herbicides
- Animal grazing
- Cover crops
- Mulching (spreading biodegradable materials)
What are the two types of fertilizer?
- Organic: derived from fresh or composed plant or animal material, possibly mown and plowed cover crop (“green manure”)
- Inorganic (synthetic): Manufactured from minerals extracted from the ground or synthetic chemicals
What are 3 advantages of organic fertilizer?
- Often cheap or free
- Some high in humus and therefore good for soil structure and water retention
- Nutrition for soil organisms, promoting living matter in soil
What are 3 disadvantages of organic fertilizer?
- Requires labor to incorporate into the soil
- Nutrients become available to the vine gradually (which may be a good thing)
- Bulky and expensive to transport and spread
What are 2 advantages and 2 disadvantages of inorganic fertilizers?
Advantages:
* Can be very tailored
* Nutrients readily available to the vines
Disadvantages:
* Do not improve soil structure or ecology (no benefit to soil organisms)
* Often more expensive to purchase (but cheaper to transport)
What are two advantages of cultivation of weeds?
i. No chemicals, so can be used in organic and biodynamic
ii. Can incorporate fertilizer and mown cover crops into soil
What are 4 disadvantages of cultivation of weeds?
i. Can damage soil structure and ecology by (i) breakdown of organic matter and (ii) disruption of earthworms
ii. Costly: skilled labor and machinery
iii. Buries seeds, encouraging weeds to grow back
iv. Can increase vine vigor, as there is no competition for water or nutrients (not a problem in low vigor sites)
What are the three types of herbicides?
i. Pre-emergence herbicides: Persist in surface layers of soil, and (i) absorbed by weeds’ roots and (ii) inhibit germination of seedlings.
ii. Contact herbicides: Kills green parts of weed they contact.
iii. Systemic herbicides: Taken in by leaves, travels up and down the weed in the sap to kill the plant.
What are three advantages of use of herbicides?
i. Cheap: little labor and machinery
ii. Highly effective, especially in under-row area
iii. Less damaging to soil structure than cultivation
What are four disadvantages in use of herbicides?
i. Risk of poising operator, consumer, and environment, and do not encourage vineyard ecosystems.
ii. Weeds can become resistant, so dosage may need to be increased (example of glyphosate-resistant ryegrass in South Africa).
iii. Can increase vine vigor too much as there is no competition for water or nutrients (not a problem in low vigor sites).
iv. Not allowed for organic or biodynamic.
What are three advantages to animal grazing?
i. Can be used in organic and biodynamic
ii. Animals can provide manure
iii. Animals can be a source of meat
What are three disadvantages to animal grazing?
i. Vines must be trained high or grazing must happen out of growing season
ii. Requires labor for animal care if they belong to vineyard owners
iii. Animals are often susceptible to vineyard pesticides
What are three examples of types of cover crops?
i. Legumes (beans, clover)
ii. Cereals (ryegrass, oats)
iii. Natural vegetation (but less control)
What are four advantages of cover crops?
i. Can be used in organic and biodynamic
ii. Increases soil biological activity and biodiversity
iii. Can influence vigor of vine by introducing competition for water and nutrients
iv. Good surface for machinery, especially in climates with high annual rainfall
What are three disadvantages of cover crops?
i. Reduction of vine vigor through competition (not a problem for high vigor sites)
ii. Difficulty of mowing under-row area, which increases time and labor
iii. Not suitable for steep slopes, as slippery when wet
What are three advantages of mulching?
i. Can be used in organic and biodynamic
ii. Can reduce water evaporation (good in dry sites)
iii. Can be a source of nutrients and humus, which promotes soil biological activity and good soil structure (esp in poor soils)
What are three disadvantages of mulching?
i. Is very bulky, so expensive to transport and spread
ii. Only effective in a thick layer, so a lot is needed
iii. Can increase vigor too much if no competition for water or nutrients (not a problem for low vigor sites)
What are the two general approaches to addressing water management?
- Irrigation
- Drainage
What are six steps to increasing water efficiency?
i. Use of water-efficient irrigation plus better monitoring (e.g., drip and regulated deficient irrigation)
ii. Use of drought-tolerant varieties (e.g., Granache) and rootstocks (e.g., 140R)
iii. Reducing evaporation (e.g., by applying mulch)
iv. Reducing competition (e.g., removing weeds)
v. Increasing humus in soil to improve retention (e.g., adding organic matter)
vi. Promoting growth of deep vine roots (e.g., through cultivation)
What are 4 advantages to drip irrigation?
- Economic use of water
- Can control water to individual rows or blocks of vines, tailoring management and possibly resulting in higher yields and quality
- Can be used to supply fertilizer (“fertigation”)
- Can be used on slopes
What are 4 disadvantages of drip irrigation?
- High cost of installation; moderate cost of maintenance
- Clean water required or drippers quickly clog
- Even with clean water, drippers gradually clog with algae, bacteria, or minerals/salts, so some maintenance is required
- Can’t be used for frost protection (aspersion)
What are 3 alternative irrigation methods other than drip?
- Flood irrigation
- Channel irrigation
- Sprinklers
What are the three advantages or disadvantages of flood irrigation?
- Cheap to install and maintain
- Inefficient
- Can only be used on flat or gently sloped land
What is channel irrigation, and what is its sole advantage?
Water flows in furrows between rows, which increases efficiency over flood irrigation
What are the 3 advantages and disadvantages of sprinklers for irrigation?
- Expensive to install and maintain due to need for high water pressure
- Not as efficient as drip
- Can be used for frost protection
What is regulated deficit irrigation (RDI)?
Schedule water deficit between fruit set and véraison to limit shoot growth and encourage grape development (can’t be too much or it will reduce yield and quality)
What circumstances are best for RDI and how is it best implemented? What needs to be true for RDI to be worth it?
- Easiest with dry growing season and sandy or loam soils that dry out and can be re-wetted quickly
- Best done with a dripper system to control
- Reduces yields, so increase in quality must make up for lost volume.
Is RDI more favored for black or white grapes, and why?
Often favored for black grapes as it reduces grape size, increasing skin to juice ratio, giving increased concentration of anthocyanins and tannins
When would artificial drainage be installed and why?
i. In sites with lots of rain and not sufficiently free-draining soils, artificial drainage systems may be installed before planting.
ii. Cost of installation and maintenance typically more than offset in medium term by having healthier, better-balanced vines.
iii. Also aids mechanization by (i) providing better surface to drive on and (ii) reducing soil compaction from driving on wet soils.
Besides installing artificial drainage systems, what are other methods to control water available to the vine?
i. Competition for water by cover crops or natural vegetation
ii. Improving soil structure and removing plough pans to better regulate water drainage
What are 3 primary considerations in choosing a training and trellising system?
- Vigor of the vine
- Topography of the (many systems can’t be used on steep slopes or windy sites)
- Need for mechanization (VSP and other trellising systems are suited for mechanization because fruit tends to be on the same area for each vine)
What factors determine vine vigor?
- Natural resources (temp, water, nutrients)
- Planting material (variety, clone, rootstock)
- Presence of disease
In addition to factors related to training/trellising techniques, what two other considerations are there for canopy management techniques?
- Vine density
- Row orientation
What determines optimal vine density?
i. Vigor of the vine
ii. Type of trellising system
iii. What access is needed between the vines
What are the two types of factors with respect to choosing row orientation?
- Climactic factors
- Logistical factors
What are two climactic factors when it comes to choosing row orientation?
- North-south orientation often provides most even sunlight, though the west side can be warmer (as exposed to afternoon sun) and thus may require more leaf shading.
- Winds: Often try to orient 90 degrees to prevailing winds
What are two logistical factors when it comes to choosing row orientation?
- Rows parallel to the longest side of the vineyard often most efficient
- With unterraced slope greater than 10%, have to orient rows up the slope, as machinery may slip.
What are the three considerations with respect to the number of buds left after winter pruning?
- More buds on more vigorous vines
- Buds left influences number and size of shoots and amount of fruit, influencing vine balance
- There are techniques to decide how many buds to retain to preserve balance, including yield and weight of pruning cuttings
How is replacement cane pruning implemented?
a. 8-20 buds
b. Typically laid down horizontally, and tied to trellis
c. A spur is left, and shoots from the spur will form the next year’s cane
What are the three advantages to using trellising?
i. Shoots can be spread out to maximize light interception
ii. Increase air flow in the canopy (reducing fungal disease)
iii. Position fruit in one area, which aid mechanization
What are the two disadvantages to using trellising?
i. Expensive to establish (especially for complex systems)
ii. Requires maintenance
What are the 3 primary aims of summer pruning?
- enhancing grape ripening
- reducing fungal disease
- making vineyard easier to manage
What is involved in disbudding?
- Remove excess buds (e.g., those left in case frost killed buds)
- Remove poorly positioned buds (facing down or too close together)
- Remove buds of non-fruit-bearing shoots (which may compete with grapes for resources)
What is involved in shoot removal?
Removal of shoots, often laterals, that are infertile or poorly positioned
What are the 7 kinds of summer pruning?
- Disbudding
- Shoot removal
- Shoot positioning
- Pinching
- Shoot trimming
- Leaf removal
- Crop thinning/green harvesting
What is shoot positioning?
Shoots tucked into the trellis wires
What is pinching?
Removing shoot tips at flowering to improve fruit set