weed and vegetation management in grape production jeffrey derr professor of weed science virginia...
TRANSCRIPT
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Weed and Vegetation Management in Grape Production
Jeffrey Derr
Professor of Weed Science
Virginia Tech
Charlottesville VVA talk 1/30/14
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2014 Pest Management Guides
Horticultural and Forest Crops
• http://pubs.ext.vt.edu/456/456-017/456-017.html
Weed control section for grapes
• http://pubs.ext.vt.edu/456/456-017/Section-3_Grapes-3.pdf
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Weed identification Books and Websites
• Weeds of the Northeast – Cornell Press
• Weeds of the South - University of Georgia Press
• Virginia Tech weed identification website:
http://oak.ppws.vt.edu/weedindex.htm
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Vegetation Management Plan
Cover crop between the rows- Erosion control, ability to drive through vineyard soon after a rain
Initially bare ground within the grape row- weeds, cover crops suppress vine growth
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Weed control in row middles
Few options after planting grapes
• Aim (carfentrazone) -contact herbicide that will control small annual broadleaf weeds.
• Establish cover crop, control broadleaf weeds, kill cover crops in strips prior to planting
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Perennial Cover Crop Evaluation for Enhanced Vineyard Floor Management
Funded by the Virginia Wine Board/ VVA/VDACS
Trials in Virginia Beach, Blacksburg, and cooperating vineyards
Evaluate cool- and warm-season perennial grasses for use between rows of grapes
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Project Goals
• Evaluate ease of establishment and persistence for cool- and warm-season cover crops between vine rows.
• Evaluate weed suppression for each perennial cover crop.
• Determine crop suitability criteria such as: traffic, drought, and cold tolerance, as well as maintenance requirements.
• Evaluate cover crop influence on overall soil health.
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Cool-season Establishment - Blacksburg
All good establishment
‘Bighorn GT’ Sheep /Hard Fescue
‘DTT-43’ Dwarf Tall Fescue
‘DTT-20’ Dwarf Tall Fescue
‘Rough and Ready’ Microclover mix*
‘Companion Grass ‘ Cover Crop Mixture**
‘Applaud’ Perennial Ryegrass
‘Fawn’ K31
‘Midnight’ Kentucky Bluegrass
‘Silverlawn’ Creeping Red Fescue
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Cool-season Establishment - Blacksburg
‘Rough and Ready’ Microclover mix* -
34% Quatro Sheep Fescue, 30% Eureka II Hard
Fescue, 30% PR8821 Perennial Ryegrass, 5 %
Microclover
‘Companion Grass ‘ Cover Crop Mixture** - 80% PR8821 Perennial Ryegrass, 20% Creeping Red Fescue
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Warm-season Establishment - Blacksburg
Poor with blue grama
Uneven with bermudagrass, zoysiagrass and
their combinations with cool-season grasses
- Weed competition
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Establishment – Virginia Beach
Good – tall fescues (Fawn, DTT 43, DTT 20, Justice), zoysiagrass + Gotham hard fescue
Poor – Kentucky bluegrass, hybrid bluegrass, Bighorn GT, Companion grass, Rough and Ready, Perennial ryegrass, zoysia + perennial; ryegrass, blue grama
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Traffic tolerance
Good with the tall fescues, Companion grass, Rough and Ready
Fair with Kentucky bluegrass
Poor to fair with Bighorn GT, creeping red fescue
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Cover crops – Cool-season glyphosate tolerant
• Big Horn GT – sheeps fescue• Aurora Gold hard fescue
• Compared to Gotham hard fescue
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Weed life cycle
Annuals
Summer - grass, broadleaf, sedge, other monocots
Winter – grass, broadleaf
Biennials – broadleaf
Perennials – grass, sedge, other monocots, broadleaves
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Summer annual grasses
Large crabgrass
Giant foxtail
Goosegrass
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Winter annual grasses
Italian (Annual) ryegrass Annual bluegrass
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Annual broadleaves
Summer common lambsquarters, smooth pigweed, common ragweed, ivyleaf morningglory
Winter vetch, horseweed, fleabane, common chickweed, henbit
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Summer annual broadleaves
Common ragweed tall morningglory
Common lambsquarters Smooth pigweed
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Winter annual broadleaves
Vetch
Common chickweed Horseweed
Henbit
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Biennials
Musk thistle Wild carrot
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Perennial Monocots
Perennial grasses• clump - tall fescue, orchardgrass• creeping - quackgrass, bermudagrass,
johnsongrass
Perennial sedges – yellow nutsedge
Other perennial monocots – wild garlic
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Bermudagrass
Perennial grasses
Quackgrass
Johnsongrass
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Yellow and Purple NutsedgePerennial sedges (rhizomes, tubers)
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Other monocots
Wild garlic (perennial)
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Perennial broadleaves
• Simple – dandelion, buckhorn plantain
• Creeping - bindweed, brambles, poison ivy, horsenettle, hemp dogbane
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Dandelion Buckhorn plantain
Simple perennial broadleaves
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Creeping perennial broadleaves
Poison ivy Horsenettle
Hedge bindweed
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Perennial broadleaf weeds
Hemp dogbane Black locust
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Grape Weed Control
• Biological – little available
• Cultural
• Chemical
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Vegetation Management Plan
• Killed strip within the row to reduce weed competition
• Mowed (grass) alleyways for erosion control, drivability soon after rain
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Site PreparationGoal is to reduce weed populations, especially for perennial weeds
• Cover crops - cropping with competitive or allelopathic crops, such as rye or sudangrass, for 1 to 2 to two years before planting
• Grow alternative crops like corn where troublesome weeds like yellow nutsedge or broadleaf weeds can be controlled using herbicides that cannot be used in fruit.
• Establish permanent cover
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Site prep - Chemical control
• Glyphosate
- apply in strips in fall for fescue, orchardgrass control
- plant into killed strips
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Cultural control
• Cultivation (mechanical) – suppress perennials, break crusts, soil erosion, root damage
• Cultivation (flame) – tree injury, fire hazard• Black plastic, fabrics – habitat for rodents,
cost• Organic mulches – improve moisture
penetration, habitat for rodents, cost
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Chemical controlPreemergence herbicides
• Match to weed problems• Apply prior to weed germination (clean
soil or add a postemergence)• Apply proper rate for soil type (organic
matter, soil texture)• Need rain or irrigation for activation• Shorter residual under wet conditions
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Preemergence herbicides for grapes – annual grasses and small-seeded
broadleaf weeds
• Surflan (oryzalin), Prowl (pendimethalin), Devrinol (napropamide) – annual grasses, some broadleaves
• Can be used at planting after soil settles
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Preemergence control – small-seeded broadleaf weeds
• Trellis (Gallery) (isoxaben)• Combine with Surflan (oryzalin), Prowl
(pendimethalin), Devrinol (napropamide) – annual grasses, some broadleaves
• Can be used at planting after soil settles• 165 day PHI
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Preemergence herbicides for grapes – annual grasses, small-seeded broadleaf weeds, suppression of yellow nutsedge
• Solicam (norflurazon)• Vines must be established 2 years
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Pre and early POST control – annual grasses, small-seeded broadleaf weeds,
suppression of yellow nutsedge, dandelion
Matrix (rimsulfuron)• Vines must be established 1 year• Short residual• Combined with Surflan, Prowl, etc. for
broader-spectrum control• 14 day PHI
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Pre and early Post control – annual broadleaf weeds, annual grasses
Goal, GoalTender (oxyfluorfen)
• vines established 3 years unless on trellis wire at least 3 feet above soil surface
• combine with Surflan, Prowl, etc. for improved annual grass control
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Chateau (flumioxazin) – grapes
• Dormant applications preferred• Treat in early spring and fall• Could add a preemergence grass herbicide,
especially under high annual grass pressure or lower rates
• Add a postemergence herbicide for control of emerged weeds
• Use directed sprays, do not apply overtop of grapes
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Chateau (flumioxazin) – grapes
• 6 to 12 ounces of product per treated acre, which equates to 0.19 to 0.38 pounds active ingredient per acre.
• Maximum use rate per year is 24 ounces of product.
• Use of 6 ounces of Chateau per acre when applications are made to very sandy/gravelly soils and tree or grape vines are established less than 3 years.
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Pre and early Post control – annual broadleaf weeds, annual grasses
Chateau (flumioxazin)• Vines established at least 2 years unless
vines protected with grow tubes, waxed containers, etc.
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Results withChateau
• Strength is annual broadleaf control
• Excellent control – common lambsquarters, pigweed, velvetleaf, jimsonweed, common ragweed, prickly sida, bittercress
Buckhorn plantain, yellow woodsorrel from seed
• Good control – annual morningglories, cocklebur
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Results with Chateau
• Fair to excellent control of annual grasses:
Large crabgrass, yellow foxtail, giant foxtail, johnsongrass from seed
• No control of yellow nutsedge or bermudagrass at use rates
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Preemergence control - annual broadleaf weeds, annual grasses
Princep (simazine), Karmex (diuron)
• Vines established 3 years• Inexpensive broadleaf control• Match rate to soil type• Combine with a grass herbicide
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Preemergence herbicides for grapes – winter applied – cool-season grasses,
winter annuals
Kerb, Casoron – winter-applied, cools season perennial grasses, winter annuals
• For control of quackgrass, tall fescue, orchardgrass, plus winter annuals
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Pre – annual grasses, annual broadleaf weeds
Alion (indaziflam)
• Vines established at least 5 years
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Alion (indaziflam)
-sprayable form 1.67 lb/gal caution label
- Preemergence with significant post activity
- different mode of action (cellulose biosynthesis inhibitor)
-directed spray
-use rate 5 fl oz/acre (0.065 lb ai/A) (only 1 appl/year at that rate)
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Alion (indaziflam)Strength – controls annual grasses (crabgrass, goosegrass, foxtails, annual bluegrass, annual ryegrass)
- many annual broadleaf weeds (jimsonweed, pigweed, horseweed, lambsquarters, velvetleaf, eclipta, spurge, henbit, chickweed, speedwell, bittercress)
- Long residual
Weakness Does not control morningglory or yellow nutsedge
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Postemergence herbicides for grapes
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Chemical controlPostemergence herbicides
• Match to weed problem• Apply to actively growing weeds (no
drought stress)• Apply under warm temperatures (60 –
85 F)• See if a surfactant is needed (nonionic
versus crop oils)
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Postemergence Grass herbicides
Perennial grasses – johnsongrass, quackgrass, bermudagrass
Annual grasses – crabgrass, foxtails, etc.• Poast (sethoxydim), Fusilade DX
(fluazifop) – 50 day PHI • Select Max – nonbearing • Add a nonionic surfactant or crop oil
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Aim (Carfentrazone)• a 1.9 lb/gallon EW or as a 2 lb/gallon EC• postemergence control of small annual broadleaf weeds.• 1 to 2 fluid ounces per acre. • Apply when annual broadleaf weeds are less than 6 inches
in height and actively growing. • does not control grasses. • can be tank mixed within other postemergence herbicides
for broader-spectrum control or with preemergence herbicides.
• Adding a crop oil concentrate or nonionic surfactant may improve weed control.
• Do not allow spray to contact green stems, leaves, flowers • Can also be used for control of suckers – see label for rates
and directions for this use.• 3 day PHI
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Rely (glufosinate)
Nonselective
• Contact with some translocation• Less effective on perennial weeds than
glyphosate but lower risk of crop injury• Apply as a directed spray when weeds are
small and actively growing • 14 day PHI
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Alternatives to Rely (glufosinate)
Nonselective
paraquat (Gramoxone)• Rapid acting contact• No effect on underground tissue –
rhizomes, roots, bulbs, etc.• Restricted use due to toxicity• Apply this contact herbicide as a directed
spray when weeds are small and actively growing
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Alternatives to Rely (glufosinate)
Nonselective
Scythe (pelargonic acid)
Acetic acid (Weed Pharm) – organic production• Rapid acting contact• No effect on underground tissue – rhizomes,
roots, bulbs, etc.• sucker control
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Alternatives to Rely (glufosinate)
Nonselective
Glyphosate (Roundup, others)• more effective on weeds (systemic)• but poses greater risk of systemic damage• apply using a shield spray or wiper
application• Keep off grape foliage, green stems• 14 day PHI
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Glyphosate
• Off patent, available under a variety of trade names (Roundup WEATHERMAX, Touchdown, etc.)
• Check label for pounds glyphosate acid/gallon• Check label for need for a surfactant• Check spray water for calcium content (hard
water) – add ammonium sulfate 8-17 lb/100 gal
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Herbicide Resistance
• Refers to a weed that used to be controlled but no longer is controlled
• Separate from tolerance where a weed species was always hard to control with that herbicide
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Horseweed (Conyza canadensis)
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Weed shifts
(Weeds less sensitive to glyphosate)
• Bengal dayflower/tropical spiderwort
• Doveweed
• Dayflower
• Morningglory
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Dayflower
Cutleaf evening primrose
White clover
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