Upload
hoangdan
View
216
Download
2
Embed Size (px)
Citation preview
Approaches to Weed Control in Vineyard Driplines
Sarah Bowman Dept. of Plant, Soil and Agricultural Systems
Southern Illinois University
2015 IGGVA Annual Conference Springfield, IL
Importance of Weed Control
• Reduce competition with vines: – Water – Nutrients – Light
• Reduce vine canopy and fruit zone interference: – Light – Air flow – Pesticide spray – Increase difficulty of canopy management and harvest
• Reduce environment for pests: – Insects – Disease – Nematodes – Rodents
• Reduce injury/annoyance for workers: – Poison ivy skin irritant – Multiflora rose, horsenettle thorns
Poor or Lack of Weed Control Encourages:
• Competition with vines
– Small vine size – Reduced yield – Poor fruit quality
• Establishment of perennial weeds – Difficult to control
• Disease – Poor fungicide interception and coverage – Downy mildew – Late season fruit rot
Excessive Competition Problematic When:
• Vines are young, weak or over cropped – Small or shallow root system
– Short stature/small canopy size
• Droughty season – Less water and nutrient availability
• Low vigor site – Eroded, tight clay soil Limited rooting volume
– Excessively well drained with no irrigation
– Nutrient deficient soil
Grower Weed Control Goals
• Control perennial weeds during site prep
• Maintain weed free strip during vine establishment (years 1 through 3)
• Provide adequate weed control throughout growing season • Adjust weed control intensity in accordance with vine needs • Promote soil health
– Reduce erosion – Increase water/air infiltration – Increase biological activity
Considerations When Choosing Weed Control Approach
• Weed identification
• Problematic weed species
• Vine age
• Vine vigor
• Site vigor
• Training system
• Site susceptibility to erosion
• Soil type
• Precipitation
• Irrigation
Approaches to Weed Control
• Traditional: herbicide bare strip
• Chemical: herbicide bare strip as needed/weed mulch layer
• Mechanical: cultivation
• Cover Crop: annual or perennial
• Organic Mulch: compost or hardwood
• Other: permeable fabric or plastic, mowing, flame burning
• Spring and late summer → apply pre-emerge residual herbicide under row
– Rotation of Princep, Karmex, Solicam
Traditional: Herbicide Bare Strip
Traditional: Herbicide Bare Strip
Advantages Disadvantages • Eliminates competition
• Herbicide resistance
• Difficult application mid/late season
• Vine injury
• Increased soil erosion
• Reduced soil water/air infiltration
• Reduced soil biological activity
• Eliminates competition
• Ease of application early in season
• Low cost
• Pre-emerge residual activity
• Systemic herbicide provides good control of perennial weeds
• Broad spectrum control
• Specific control
Herbicide Bare Dripline Leads to Soil Erosion
• Spring →apply pre-emerge residual herbicide under row
– Rotation of Princep, Karmex, Solicam
– Use less than full rate
• Follow up (5-6 weeks later) apply mix of residual + burndown
Chemical: Herbicide Bare As Needed/ Weed Mulch Layer
Chemical: Herbicide Bare As Needed/ Weed Mulch Layer
Advantages • Reduces competition • Reduces damage to soil health • Increase soil air/water
infiltration • Increase soil water retention • Ease of application early in
season • Low cost • Pre-emerge residual activity • Systemic herbicide provides
good control of perennial weeds
• Broad spectrum control • Specific control
Disadvantages • Time sensitive
• Difficult application mid/late season
• Vine injury
• Herbicide resistance
• Rodent pressure
Choose and Apply Herbicides Wisely
• Pre-emerge with post-emerge activity can damage trunk renewals – Protect renewals with grow tubes, or use product with
no post-emerge activity
• Pre-emerge can damage vine roots on sandy, low organic matter, low clay soils
• Perennial weeds best controlled with systemic herbicide
• Grass weeds can be controlled with selective grass herbicide
• Always practice herbicide rotation to avoid resistance
• Always read herbicide label • Take the time to calibrate sprayer
• Cultivate when average weed height is 4 to 6” • Repeat as necessary
– Frequency of cultivation increases with frequency of precipitation
• Implement Options:
– Weed badger – Grape hoe – Weed knife
Mechanical: Cultivation
Mechanical: Cultivation
Advantages • Reduces competition
• Applied as needed
• Broad spectrum control
Disadvantages • Encourage weed seed
germination
• Requires special equipment
• Injury to vines
• Root pruning
• Damage to soil structure – Breaks aggregate structure
and increase soil susceptibility to erosion and crusting
• Decreased soil organic matter
• Light cultivation to prepare seedbed
• Annual, spring seeded: cereal rye, oats
• Annual, fall seeded: cereal rye, wheat
• Perennial, fall seeded: red fescue
• Grass cover crop species can be controlled with selective grass herbicide
• Fertilize and control weeds to encourage strong stand development
Cover Crops: Annual or Perennial
Cereal Rye
May June July
Red Fescue as Living Mulch
May July Aug. Nov.
Cover Crops: Annual or Perennial
Advantages • Reduced erosion
• Increased soil water/air infiltration
• Increased organic matter
• Increased soil biological activity
• Grass cover crops can reduce broadleaf weed pressure
Disadvantages • Competition with vine
• Time sensitive management
• Intensive management – Establishment
– Stand maintenance
• Escape weeds require spot treatment
• Composted winery waste
• Hardwood bark mulch
• Shredded or composted corn stalks
• Straw
• Grow your own
• Carbon to nitrogen ratio and thickness of mulch layer influences mulch persistence
• Adjust fertility to reduce negative impact of nitrogen immobilization
Organic Mulch
Bark Mulch + Composted Winery Waste
June October
Organic Mulch
Advantages • Reduced competition with
vine for soil water
• Increased moisture retention
• Reduced erosion
• Increased organic matter
• Increased rooting volume
• Increased root zone cooling
• Utilization of winery waste
• Source and slow release of N,P,K,
Disadvantages • Weed seed in mulch source
• Nitrogen immobilization
• Increased rodent pressure
• Impact on fruit chemistry
Other Forms of Weed Control
• Inorganic Mulch: Permeable fabric or plastic
• Mowing
• Flame Burning
Weed Control as a Vine and Soil Health Tool
• Eliminate, reduce, or encourage competition to promote or reduce vine vegetative growth
– Eliminate competition: young or weak vines, drought
– Promote competition: extremely vigorous vines, wet seasons
– Reduce competition: balanced vine growth, adequate but not excessive rainfall
What to Look For: The Visual Symptoms of Healthy, Balanced Vines
• Leaf color: Deep green
• Shoot length: 3 to 4 ft.
• Shoot Diameter: Pencil size
• Leaf number: 12 to 20 leaves/shoot
• Lateral length: Less than 1 ft.
• Tendril length: Extending just past growing tip
Weed Control as a Vine and Soil Health Tool
• Eliminate, reduce, or encourage competition to promote or reduce vine vegetative growth – Eliminate competition: young or weak vines, drought – Promote competition: extremely vigorous vines, wet – Reduce competition: balanced vine growth, adequate but not
excessive rainfall
• Allow moderate weed growth (8 to 10”) before burndown application to create mulch layer – Protect soil from erosion – Increase soil water/air infiltration – Maintain or increase soil organic matter
Grower Weed Control Goals
• Control perennial weeds during site prep
• Maintain weed free strip during vine establishment (years 1 through 3)
• Provide adequate weed control throughout growing season • Adjust weed control intensity in accordance with vine needs • Promote soil health
– Reduce erosion – Increase water/air infiltration – Increase soil biological activity
Summary
• Rigorous weed control is necessary for young or weak vines, or during drought conditions
• Avoid using herbicide bare culture just for aesthetics
• Remember to scout for symptoms of vine stress, balance, or excessive vigor and use weed control as a vine growth tool
• Use weed control practices that promote soil health – Reduce erosion
– Promote soil water/air infiltration
– Increase soil biological activity
Approaches to Vineyard Weed Control Sources:
• Midwest Grape Production Guide, Bulletin 919, OSU Extension
Authors: I. Dami, B. Bordelon, D.C. Ferree, M. Brown, M.A. Ellis, R.N. Williams, D. Doohan
• Wine Grape Production Guide for Eastern North America, NRAES-145, Virginia Tech
Editor: T.K. Wolf
• Midwest Small Fruit and Grape Spray Guide, Bulletin 861, OSU Extension
Thank You For Your Attention!
Acknowledgements:
Illinois Grape Growers and Vintners Association
Conference Attendees