D8: Hazards, Pests and Diseases Flashcards

1
Q

Name 9 hazards which can have an impact on grape growing

A
  • drought
  • excess water
  • untimely rainfall
  • freeze
  • frosts
  • hail
  • sunburn
  • fire
  • smoke taint
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2
Q

DROUGHT

what is the minimum amount of water a vine needs in a) cool climate and b) warm climates?

A

Cool: 500mm

Warm: at least 750mm

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3
Q

DROUGHT

what happens to the vine with lack of water?

A
  • stomata closes in order to limit water loss
  • this reduces photosynthesis which then stops the plant growing. This impacts the size of the grapes and ripening also slows
  • causes unripe grape
  • if has lack of water for too long, vines lose their leaves and die
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4
Q

DROUGHT

What can happen to vineyards where water is scarce and irrigation is limited? Give examples

A
  • can lose whole vineyards

EXAMPLE: Olifants River in South Africa

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5
Q

DROUGHT

What are the management options for drought?

A
  • irrigation (where permitted)
  • drought resistant rootstock (e.g. 110R or 140R)
  • drought tolerant grapes (e.g. garnarcha)
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6
Q

Name two drought resistant rootstock

A

100R and 140R

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7
Q

Name a drought tolerant grape variety

A

Garnacha

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8
Q

EXCESS WATER

Excessive water can lead to…

A

1) excessive vegetative growth

  • too shady, too much competition for nutrients
  • leads to less ripeness

2) fungal disease due to high humidity
3) waterlogged soils

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9
Q

EXCESS WATER

What is the impact of waterlogged soils?

A
  • reduces oxygen in soil
  • slows growth
  • eventually kills the vine
  • causes compaction in soil so difficult to work and can cause uncontrolled water run off
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10
Q

EXCESS WATER

What are the management options for Excess Water?

A
  • slope planting
  • free draining soils
  • construction of drainage systems
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11
Q

UNTIMELY RAINFALL

What two conditions can this cause during pollination and fruit set?

A
  • coulure
  • millerandage
  • reduces crop size and lowers quality
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12
Q

UNTIMELY RAINFALL

What else does this impact?

A
  • rate and ripening of fruit as you want some water deficiency before veraison
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13
Q

UNTIMELY RAINFALL

What can happen if there is rainfall before harvest

A
  • swollen and splitting grapes
  • rot
  • also makes machine harvesting difficult
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14
Q

UNTIMELY RAINFALL

What are the management options?

A
  • think about site choice, soil and drainage adequacy

- monitoring weather around the harvest

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15
Q

FREEZE

At what temperature can a vine be killed or damaged?

A
  • below -20 degrees/-4 Fahrenheit
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16
Q

FREEZE

What part of the vine is most at risk?

A
  • graft

- then canes/cordons

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17
Q

FREEZE

What three places are most at risk

A
  • Canada
  • Washington State
  • China
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18
Q

FREEZE

What are the management options?

A
  • site selection
    • hillsides are warmer than plains
    • near a body of water
    • plant where deep snow settles as protects vine
  • varieties
    • resilient (cab franc, riesling)
    • winter hardy (Concord - tolerant up to -35 degrees or other mongolian varieties)
  • protection
    • hilling up/building soil around vine graft
    • burying vines (often seen in China)
    • prune vines to have several trunks so can replace any that are killed
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19
Q

FROSTS

What happens when freeze occurs?

A
  • when cold air below zero degrees collects at ground level, it freezes water in vines growing buds and shoots
  • will kills any newly burst buds or young shoots which have a high water content
  • impacts yield and quality
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20
Q

FROSTS

Where is the risk highest for frost?

A
  • areas with cool and warm climates

- if buds are killed, secondary buds take much longer to grow and establish

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21
Q

FROSTS

What are the two different types of frost which can occur?

A

ADVECTIVE FROSTS
- large volumes of cold air moving in from very cold areas

RADIATIVE FROSTS

  • result of heat being lost on still, cool nights.
  • allows for layer of freezing, cold air to develop just above the surface of soil.
  • collects in valley bottoms
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22
Q

FROSTS

What are the management options?

A
  • site selection (avoiding frost pockets)
  • delay pruning so as to delay budburst
  • chose late budding varieties
  • train vines high
  • have bare soil between vines so as to radiate heat at night
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23
Q

FROSTS

What can you do when frost threatens?

A
  • water sprinklers: as water freezes around the plant, it releases latent heat and protects the plant
  • wind machines: pulls warm air from above down to the ground level
    • needs INVERSION LAYER: warm air zone 10m above ground
    • expensive but main cost is upfront
  • oil or propane heathers: placed around vineyards and lit when risk of frost
    • costly, labour intensive and not environmentally friendly
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24
Q

HAIL

What damage can hail do to a vineyard?

A
  • damage and rip young shoots and leaves
  • damage grapes and become entry points for botrytis and disease
  • reduce yield at the time and in future seasons
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25
HAIL What are the management options for hail?
- rockets fired at thunderclouds (so it falls as rain and not as hail) - net fruit zone (can only do in high sunlight areas as it causes shading) - have plots in different areas - crop insurance
26
SUNBURN - what issues does sunburn cause?
- limits grape transpiration so grapes reach higher temperatures than the leaves and become burnt - higher risk if vine is already water stressed - can cause scars on skins and leads to death of the grape - negatively impacts grape quality (browning, bitter taste, risk of rot) - need to ensure sunburnt grapes are removed at sorting which decreases yield
27
SUNBURN What are the management options?
- row orientation and aspect so can manage sun exposure - canopy management (so can try and shade fruit) - additional irrigation in a heatwave - agricultural sunscreen can be applied or shade can be provided with cloth or netting
28
FIRE Where are the areas with the highest incidences of fire?
- california - australia - chile
29
FIRE What are the worst conditions/places for areas with high fire risk?
- near woods - near pastures - crops using mulch ** all are fire risks
30
FIRE What are the management options?
- installing fire detectors and sprinklers - water tanks - employee training
31
SMOKE TAINT What is the impact of smoke taint?
- can cause 'smoky' or 'plastic' aromas in final wine - impact increases from veraison onwards - aroma compounds in smoke can be absorbed by grapes - once in grapes, compounds bind with sugars and form aroma-less precursors * these only become aromatic during fermentation and develop/increase with ageing
32
SMOKE TAINT What are the management options?
- can test must analytically by MICRO-VINIFICATIONS to see if there is a problem - hand harvesting, gentle or whole-bunch pressing, lower fermenting temperatures and reduce maceration can reduce uptake of compounds - flash detente and reverse osmosis can help but won't remove taint completely
33
What impact can PESTS have?
- compete for water or nutrients - can directly attack the vine and/or grapes so affect yield and quality - some pests and diseases are result of being transferred to territory with no previous resistance e.g phylloxera in Europe
34
PHYLLOXERA what does Phylloxera do?
- insect feeds on and lays eggs on roots of grape vines - weakens roots, causing swelling and cracks which leads to rot - spreads through crawling or flying - usually via humans on roots, soil, equipment, irrigation systems
35
PHYLLOXERA What are the symptoms of phylloxera?
- vines die of drought and patches increase year on year - roots are covered with insects surrounded by yellow eggs - swellings on older roots - pale green leaf galls on under-surface of leaves - slow, stunted shoot growth and leaf yellowing appears around 3 years, and then plant dies after about 5 years
36
PHYLLOXERA When was Phylloxera introduced/identified?
- 1863 | - destroyed 2/3rds vineyards in late 19th Century
37
PHYLLOXERA What are the management options for Phylloxera?
- use of american rootstocks which form seals around the wounds which prevent invasion by bacteria or fungi. Need to be paired with European vines as rootstocks don't give pleasant wine! - 3 american rootstock varieties: * v. berlandieri * v. riparia * v. rupestris
38
PHYLLOXERA What are the issues associated with using american rootstocks?
- issues on calcerous soils. Can cause chlorosis - have created rootstock hybrids between american species so as to balance protection and resistance to lime in soil - american rootstocks which were developed could deal with a number of problems (phylloxera, nematodes, extreme soil pH, water stress, salinity) as well as can control vine vigour - today a vineyard would get tailored advice on choice of rootstock and grape variety to match to their vineyard
39
NEMATODES What are nematodes?
- tiny worms found in soils
40
NEMATODES What issues do nematodes cause?
- feed off vine roots, reducing yield and vigour - cause slow decline of vine - can transmit viral diseases (e.g. fanleaf virus)
41
NEMATODES What are the two most common nematodes?
- root-knot nematode - daggar nematode - either found in the soil or - spread by unclean nursery stock, irrigation or vehicles - can never be eliminated - only managed
42
NEMATODES What are the management options for nematodes?
- need to take soil samples to lab to determine number and type - can leave soil to fallow for number of years (very expensive as no crop!) - fumigate soils - have to use chemicals which are mostly banned now - plough in cover crop of mustard plant which contains compounds which work as BIOFUMIGANTS, killing the nematodes - best solution: nematode resistant rootstocks
43
GRAPE MOTHS What issues do grape moths cause?
- can attack at different times * flowers in spring * grapes later on - create wounds which cause more issues later one and can lose a lot of crop
44
GRAPE MOTHS what are the three most common grape moths?
- light brown apple moth (australia) - european grapevine moth (southern europe) - grape berry moth (central and eastern north america)
45
GRAPE MOTHS What are the management options for grape moths
- insecticides - biological controls * bacterium BACILLUS THURINGIENSIS * produces a substance toxic to moths * sexual confusion (using pheremone capsules) * natural predators (parasitic wasps, green lacewings, some spiders)
46
SPIDER MITES What issues to spider mites cause?
- most detrimental mite to vines - differ from region to region - feed on surface cells of leaves which leads to: discolouration, reduction in photosynthesis, delays in ripening, reduces yields
47
SPIDER MITES What conditions to spider mites thrive in?
- dusty conditions | - especially damaging when vine is water stressed
48
SPIDER MITES Name 3 types of spider mites
- pacific spider mite (california) - red spider mite (europe) - two forms of yellow spider mite (europe)
49
SPIDER MITES What are the management options?
- create an inhospitable environment * sprinklers * cover crops etc - encourage predatory mites that feed on spider mites - general pesticides
50
BIRDS What damage can birds cause?
- can destroy an entire crop as ripening occurs - this is especially prevalent if vineyard is isolated and is the only source of food - bird damage allows bacteria and fungi to enter bunches which causes rot - starlings are biggest risk
51
BIRDS What are the management options?
- netting (very expensive!) They use this in Mornington Peninsula - bird scarers, noises etc. Need to rotate often so don't become used to them - falcons used to deter birds
52
MAMMALS What problems do mammals cause?
- eats shoots, grapes, leaves - break grape skins, which make them vulnerable to rot - damage trellising - lowers yield - lowers quality - costs to repair damage
53
MAMMALS What do the pests include?
- deer - rabbit - kangaroos - racoons - wild boar - baboons
54
MAMMALS What are the management options?
- fencing - needs to be high enough and sunk deep enough to stop animals jumping or burrowing
55
Name the 6 pests which can cause issues to grape growing
- phylloxera - nematodes - spider mites - grape moths - birds - mammals
56
Name the 6 fungal diseases which cause issues to grape growing
- powdery mildew - downy mildew - grey rot - eutypa dieback - phomopsis cane and leaf spot
57
POWDERY MILDEW What fungus causes powdery mildew?
ERYSIPHE NECATOR - aka OIDIUM TUCKERI - its grapevine specific but american species are less vulnerable than v. vinifera - most widespread vine disease in the world
58
POWDERY MILDEW What two varieties are most prone to the disease and which two are less prone?
- PRONE: Cab and Chardonnay | - LESS PRONE: Riesling and Pinot Noir
59
POWDERY MILDEW How does it attack vines?
- overwinters in buds and on canes - attacks young green parts of vine - starts dull grey and then becomes black - patches damage young shoots, inflorescences and grapes - reduces yields - can cause grapes to split during veraison and become targets for other infections
60
POWDERY MILDEW What is the optimum temperature for growth for powdery mildew?
- 25 degrees - thrives in the shade - doesn't require high humidity and can spread in dry conditions
61
POWDERY MILDEW What are the management options?
- OPEN CANOPIES: reduce shade and leaf density - SULFUR: helps prevent and treat. Spray from budburst to veraison. Need to spray early to prevent rather than contain - SYSTEMIC FUNGICIDES: penetrate green tissue, not washed off by rain. Can become resistant so limit applications
62
DOWNY MILDEW What is it caused by?
- PERONOSPORA: water mould that lives within vine tissue. Common in most wine regions - attacks green parts of plants, especially young leaves and flowers. Reduces yield by defoliating vines
63
DOWNY MILDEW What does it need to spread?
- rainfall | - warm temps of approx 20 degrees
64
DOWNY MILDEW What are the symptoms?
- yellow, circular 'oil spots' | - white, downy fungal growth on underside of leaves
65
DOWNY MILDEW What are the management options?
- sprays of copper salts e.g. BORDEAUX BLEND - combo of copper sulfate and lime. * protection doesn't last long - only until 20mm rain has fallen - fungicides - applied from month after budburst to veraison - good drainage and an open canopy
66
GREY ROT What is it more commonly known as?
- botrytis cinerea
67
GREY ROT What issues does it cause?
- loss of yield and drop in quality of wine - grapes need to be selected out at harvest - grapes are very vulnerable if there is a point of entry and whole bunches can be attacked - if flowers are affected, fungus can stay dormant until after veraison
68
GREY ROT What grapes are most at risk?
- grapes with tight bunches or thin skins are most at risk - Sauv Blanc - Semillon - Pinot Noir
69
GREY ROT When do spores become active?
- in periods of rainfall and high humidity
70
GREY ROT What are the management options?
- choosing grapes with thick skins and higher resistance - protecting grapes from pests - keeping the canopy open, removing leaves around bunches - fungicides (not copper or sulfur) - apply when flowering nearly complete, end of grape formation, bunch closure and veraison. Not very effective as fungus develops resistance - antagonistic bacteria - BACILLUS SUBTILIS - can also use other forms of biological controls
71
EUTYPA DIEBACK What is it and what does it cause?
- AKA 'dead arm - fungal trunk disease leading to rotten wood in vines - reduces yields - kills vines over 10 year period if not tackled
72
EUTYPA DIEBACK How does it spread?
- spores spread by wind over long distances - occurs through pruning wounds in moderate temperatures - especially during rain - effects are evident in spring as short young shoots come through and yellow leaves
73
EUTYPA DIEBACK What grape varieties are particularly susceptible?
- grenache - cab - sauvignon blanc
74
EUTYPA DIEBACK Which regions are particularly susceptible?
- South Australia - SW france - California
75
EUTYPA DIEBACK What are the management options?
- v difficult to control - pruning late and applying fungicide to the pruning wounds - cut back affected trunks 5-10cm beyond visible symptoms - burn dead wood to avoid spreading - biological controls - BACILLUS SUBTILIS - if badly affected, retrain from sucker (shoot that grows from base of the vine) which would take 2 years, or remove the vine and replant
76
PHOMOPSIS CANE AND LEAF SPOT What is it and when does it occur?
- fungal disease causing reduction in crops | - prevalent where cool and wet springs are followed by humidity and moderate temperatures
77
PHOMOPSIS CANE AND LEAF SPOT - what does it present as?
- canes whiten and break off easily - shoots growing from canes develop brown cracks at bases - leaves can also be affected
78
PHOMOPSIS CANE AND LEAF SPOT what grapes are most susceptible?
- grenache | - cab sauv is less affected
79
PHOMOPSIS CANE AND LEAF SPOT What are the management options?
- fungicide applied three weeks after budburst and every 2 weeks if wet conditions continue - diseased wood removed and burned - prune early or late, and not when its raining
80
ESCA What is it?
- complex fungal disease caused by groups of organisms prevalent in warmer/drier climates (e.g. S Europe, California) - enters pruning wounds - reduces yield of plant and causes it to die
81
ESCA How does it present?
- tiger striping of leaves | - spotting inside wood
82
ESCA What are the management options?
- all about disease prevention - disease-free stock - less detrimental pruning - not pruning in the rain - removing prunings from vineyard - disinfecting pruning wounds
83
What are other possible fungal diseases which need to be considered?
- black rot - black-foot disease - bot canker - anthracnose
84
What two bacterial diseases need to be considered?
- Pierce's disease | - grapevine yellows
85
PIERCE'S DISEASE What is it?
- kills vines quickly - believed to have american origins as present in California - bacterium lives in sap channels of vines causing them to clog, shrivel and drop their leaves - vines typically die between 1 and 5 years
86
PIERCE'S DISEASE How is it spread?
- by a sharpshooter insect (vector)
87
PIERCE'S DISEASE What are the management options?
- no chemical control so need to test vines in labs - need to reduce number of vectors by: * removing vines close to rivers as riverbanks harbour vectors * chemical insecticides * wasps which feed on eggs of sharpshooters - strict quarantine on movement of plants - development of Pierce's Disease resistant vines
88
GRAPEVINE YELLOWS What is it?
- group of diseases cause by type of bacteria | - serious threat as no treatment
89
GRAPEVINE YELLOWS How is it spread?
- spread by vectors including leafhoppers and by nurseries selling diseased, untreated stock
90
GRAPEVINE YELLOWS What is it commonly known as in Europe?
Flavescence Doree
91
GRAPEVINE YELLOWS Where else is it commonly found?
- germany - france - s Europe - NY State - Australia
92
GRAPEVINE YELLOWS What are the symptoms?
- delayed budburst - drooping posture (new shoots fail to lignify) - canopy turning yellow (white varieties) or red (black varieties) - vine either dies or can recover after an attack
93
GRAPEVINE YELLOWS What are the most vulnerable varieties
- Chardonnay | - Riesling
94
GRAPEVINE YELLOWS What are the management options?
- no control - need to control the vector e.g. control the leafhopper with insecticides, removing cover crops etc - Nurseries need to bathe pruning wound in hot water to kill disease
95
Name two other bacterial diseases
- bacterial blight | - crown gall
96
Name two viruses which cause issues in the vineyard
- fanleaf virus | - leafroll virus
97
FANLEAF VIRUS What is it?
- longstanding group of diseases - found around the world
98
FANLEAF VIRUS What happens to the vine?
- early shoot growth stunted - canes distorted - pale leaves which are malformed and look like fans - can lose most of the crop in some cases
99
FANLEAF VIRUS How is it spread?
mainly spread with DAGGER NEMATODES - historically spread on grafted vines using infected plant material
100
FANLEAF VIRUS What are the management options?
- no cure - infected vine needs to eventually be removed - before replanting, need to test the soil for presence of dagger nematodes - should only use virus-tested clean planting materials
101
LEAFROLL VIRUS What is it?
- group of viral diseases widely present around the world
102
LEAFROLL VIRUS How is it spread?
- spread by grafting | - spread by MEALY BUGS (SA, Mediterranean, Argentina, California)
103
LEAFROLL VIRUS What does it do?
- doesn't kill but does reduce yield by half - affects quality of grapes - slows down growth of roots and shoots * can take fruit additional weeks to ripen and have more acidity, less colour and lower sugar levels - affect carb stores in vines
104
LEAFROLL VIRUS When does it usually occur and how does it present?
- in autumn - leaves change colour to red (black grapes) or yellow (white grapes) - have to lab test vines as can carry virus without showing symptoms
105
LEAFROLL VIRUS What are the management options?
- no cure - only solution is to remove unproductive vines and replant with virus free stock - nurseries need to screen for infection - open canopies to reduce humid environment