Term
| What are the 6 types of bunch rots |
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Definition
Penicillium spp. (blue mold)
Botryosphaeria ribis
Alternaria (occurs early in season, often w/out rain)
Botrytis cinerea
Rhizopus spp.
Aspergillus spp. |
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Term
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Definition
Fungus overwinters in the grape mummies
Infections spread from berry to berry
Especially prone in compact bunches
Easy entry for insects |
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Term
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Definition
Also known as blue mold
Occurs in all grape growing countries
Stems and berries show white mold-gives rise to greenish-blue spores
Decayed tissues are soft and watery with a characteristic moldy odor
Treat raisin vineyards with sulfur |
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Term
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Definition
Coarse white mold strands can be seen
Smooth spherical spore heads are white initially and then turn black
Exist in the soil and on plant debris
Infection can occur before, during or after harvest
Primary infections usually though injuries but can break the intact berry skin
Spread from berry to berry and under warm conditions, decay is rapid
Remove split and injured berries |
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Term
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Definition
Reduces fruit set and yield
All Vitis species are susceptible
Yellow mosaic pattern on leaves, open petiole sinus
Transmitted by the dagger nematode
Can also be graft transmitted |
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Term
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Definition
Graft transmitted
Vectored by melybugs and scale insects
Foliar symptoms develop late in season
Yellowing between veins of white cultivars
Red color development in red and black cultivars
Leaves curl downwards
Crop loss, loss of sugar content, delayed maturity, coloring problems |
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Term
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Definition
Begins at bud burst and favors mild cloudy weather
Found in the shady parts of the vineyard
Temperature >35C reduce fungal growth on exposed leaves, but not in canopy
Can develop under relatively dry conditions
Causes severe crop loss
Spreads slowly
Symptoms on leaves, shoots, and clusters |
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Term
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Definition
Spreads in warm, wet conditions
Cannot spread without rain
Yellow oil spots on leaves with white downy spots beneath
Spots can grow rapidly and later dries out
Can infect shoots and leaf veins
White downy growth on cluster-berries susceptible 5-6mm in diameter
All varieties susceptible |
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Term
| What is the 10-10-24 rule of Downy mildew |
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Definition
10-10-24 rule to release spore in the soil
10 mm rain
10C temperature
24 hour period |
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Term
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Definition
Root rot organism
Consistent in areas with high temperature-SJV
Withering of the plant and wood degradation-can enter via pruning wounds
Might be the same disease as black measles
Warm, temperate climate
Symptoms appear on all parts of the vine
Control with liquid lime sulfur
2 forms of Esca
-Foliar deterioration
-Acute characterized by sudden death of the vine |
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Term
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Definition
Bud break delayed or even prevented in infected vines
All green plant tissue susceptible
Rain promote spore dispersion
Dry weather will stop fungus growth |
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Term
| Eutypa dieback and botryosphaeria canker |
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Definition
Caused by several fungi
Decrease the lifespan of vineyards
Reduce yield due to loss of productive wood
Dead spurs, arms, and cordons
Eutypa-in spring, shoots stunted and chlorotic
Darkened cankers in cross sections of wood for both
Botryosphaeria spp.-no leaf symptoms |
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Term
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Definition
Bacterium multiplies in the xylem and block water movement-drought symptoms
Diseased vines might die 1-2 years after infection
Present in CA since the 1880's
Spread by xylem feeding insects-Glassy winged sharpshooter |
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Term
| What are Pierce's disease late season symptoms |
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Definition
Leaves scald in concentric rings
Leaf blades abscise, but petioles stay attached to canes
Bark matures irregularly
Cluster can raisin |
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Term
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Definition
Berry color uniformity
Seed traces
Berry size uniformity
Scarring
Berry crack(pre- and post-harvest) |
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