managing pests & disease in the vineyard
TRANSCRIPT
Managing Pests & Disease in the Vineyard
Michael Cook
Who is this guy?
1) Pierce’s Disease2) Pest & Disease Pressure – fungal 3) Late Freeze4) Rain – excess and timing5) Vigor6) Variety Selection7) Hail8) Labor 9) Suppliers10)Education
Challenges Facing Growers
Diseases
?
PrecipitationHeavy DewHigh Humidity Levels (dense canopy)
The Environment
Proper Canopy Architecture is CRITICAL
Manage vine vigor◉irrigate but do not over irrigate◉be judicious with fertilizer applications,
especially N◉conduct good canopy management practices◉ leaf removal, shoot thinning, summer
pruning
It’s a constant battle of vegetative growth, it needs to be managed
How to keep an open canopy in Texas
Spores are present on ◉wild grapes◉ tolerant cultivars◉neighboring vineyards◉old wood that was previously infected◉pruning trash◉vineyard floor
The pathogen is here, its just a matter of time your vineyard sees them!
The Pathogen
No single variety tolerant of all fungal pathogens
Host
Table courtesy of Dr. Justin Scheiner
Fungal PathogensDormant 1”
Shoots3 - 5”
Shoots 10 - 12” Shoots
TrunkDiseasesAnthracnose
PhomopsisPowderyMildew
PhomopsisBlack rotPowderyMildew
PhomopsisBlack rotPowderyMildewDowny Mildew
Images courtesy of Dr. Justin Scheiner
Anthracnose Distribution: everywhere except West TX Conditions for infection: 12 hrs. of leaf
wetness, 36 to 90oF◉wet conditions promote further spread
Phomopsis Distribution: statewide Conditions for infection: rainy weather during
early season◉ leaf and cane lesions typically appear in 3 to 4
weeks
Images from: Dr. Justin Scheiner and Fritz Westover
Black Rot
Images from: Cornell Cooperative Extension Disease ID Sheet No. 102GFSG-D4
Distribution: statewide Conditions for infection: ≥ 50oF and leaf wetness◉at optimal temperature (80oF), only 6 hours of leaf
wetness is required
Powdery Mildew Distribution: statewideConditions for infection: ≥ 50oF and ≥ 0.1” rain
moisture is not required after initial infection
Downey Mildew Distribution: everywhere except West TX Conditions for infection: ≥ 52oF and ≥ 0.1” rain◉4 to 5 day cycle if conditions are favorable (warm
and moist)
When are grapes susceptible to disease?
All season◉most critical period is 2 weeks before bloom through 4-6
weeks post-bloom ◉ use your best systemic products at this time
Grape varieties + phenology + diseases + weather + fungicides
Fungicides
1. Develop your own spray management strategy2. Scout for disease, not just on the weekends3. Keep that canopy open4. Monitor weather conditions as if you were a
meteorologist5. Keep good spray notes6. Be adaptable (do not rely on a rigid spray plan)7. Change nozzles/filters and calibrate sprayer
Fungal Control Solutions
Rotate to Prevent Resistance
Follow the Label…..It’s the Law!
over 20 fungal pathogens responsible, usually found as a complex
slow spreading diseasesymptoms more noticeable with older
vineyardsspread by injury (pruning wounds, freeze
damage, etc.) looking for dead spots, internal tissue
discoloration, splits/cracks, foliar symptoms
Grapevine Trunk Diseases (GTD’s)
Eutypa
Images courtesy of Dr. Justin Scheiner
Esca
found on calcareous sites (soil pH 7.0 +) found across the state look for vine collapse during stress periods, leaves
attached vine often pulls out of ground easily (roots rotted) confirm by sending off sample to lab Rogue or Topguard Terra
Cotton Root Rot (CRR)
Image courtesy of Dr. Justin Scheiner
Bunch RotsBotrytis
Ripe RotSour Rot
Bitter Rot
Spread via wounding◉Fruit splitting/cracking◉ Insect Damage◉Fungal Damage◉Vertebrate Damage
Bunch Rots
Crown GallPierce’s Disease
Crown Gall Agrobacterium vitis Survives systemically Injury (freeze, weed eater) activates Leads to vine decline and death ROGUE – NO CURE
Bacterial Diseases
Disease Testing
Insect Pests
Manage pest population◉Chemically with insecticides◉ foliar spray or chemigation
◉Culturally◉ clean up property◉ suppress weeds
◉Biologically◉most not economically feasible
commercially
Insect Solutions
Pheromone Traps
1. check stock of chemicals/fertilizers2. vine health check – disease management3. Chemigation/irrigation inspection4. sprayer calibration – check nozzles &
output5. go over spray management program
Get ready for a great 2018!
winegrapes.tamu.eduGrowing Grapes in Texas – Jim Kamas
Texas Grape Pest Management GuideCompendium
Further Resources
