Weed IPM in Grape Production
Jeffrey Derr
Professor of Weed Science
Virginia Tech
IPM workshops 2014
2014 Pest Management Guides
•Horticultural and Forest Crops
•http://pubs.ext.vt.edu/456/456-017/456017.html
•Weed control section for grapes
•http://pubs.ext.vt.edu/456/456-017/Section3_Grapes-3.pdf
Weed identification Books
• Weeds of the Northeast – Cornell Press
• Weeds of the South - University of Georgia Press
Additional Information
Virginia Tech Weed ID websites
http://oak.ppws.vt.edu/weedindex.htm
www.ppws.vt.edu/ipm/weeds_container_nurs
eries.html
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
Site Preparation
Goal is to reduce weed populations, especially for
perennial broadleaf 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 grape production
• Establish permanent cover before planting
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
Site prep - Chemical control
• Glyphosate
- apply in strips in fall for fescue,
orchardgrass control
- plant into killed strips
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
Proposed new research – evaluate cover crops
within the row, continue evaluating between
row cover crops
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.
Cover crops – Cool-season
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Tall fescue – standard + dwarf types
Creeping red fescue
Hard fescue
Perennial ryegrass
Kentucky bluegrass
Hybrid bluegrass
Cover crops – Cool-season
Prepackaged Combinations
• Companion grass – dwarf perennial
ryegrass + creeping red fescue
• Rough and Ready- dwarf perennial ryegrass
+ turf type fescues + microclover
Cover crops – Cool-season
glyphosate tolerant
• Big Horn GT – sheeps fescue
• Aurora Gold hard fescue
• Compared to Gotham hard fescue
Cover crops – Cool-season
glyphosate tolerant
• Big Horn GT – sheeps fescue
• Aurora Gold hard fescue
• Compared to Gotham hard fescue
Cover crops – Warm-season
• Zoysiagrass
• Bermudagrass
• Blue grama
• Combinations with perennial ryegrass or
hard fescue
Results – Warm season trials
Difficult to establish in existing grape plantings due to the
lack of safe herbicides for both the perennial grass and
grapes
Bermudagrass establishes much better from seed than
zoysiagrass but will be more competitive
Blue grama did not do well in our trials
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
Cool-season Combination Seed Mixes
‘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
‘Southern States Premium Tall Fescue with Eco-Green’ DTT 20 + DTT 43 tall fescue cultivars
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
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
Grass
species
Cultivar
Seeding rate Establish
lb/1000 sq ft rate 1-10
Weed
Supp 1-10
Hard fescue Bighorn GT
2
2
6
Dwarf tall
fescue
DTT20/DTT43
blend
2
4
6
(mix)
Rough and
Ready
5
7
8
(mix)
Companion
grass
1
5
8
Perennial
ryegrass
Applaud
5
9
6
Tall fescue
Fawn
2
8
6
Kentucky
bluegrass
Midnight
1
1
4
Creeping
red fescue
Silverlawn
2
5
10
Grass
species
Cultivar
Hard fescue
Bighorn GT
3
9
20
Dwarf tall
fescue
DTT20/DTT4
3 blend
10
8
27
(mix)
Rough and
Ready
10
8
21
(mix)
Companion
grass
10
8
25
Perennial
ryegrass
Applaud
9
7
20
Tall fescue
Fawn
9
4
55
Kentucky
bluegrass
Midnight
6
7
16
3
5
33
Creeping red Silverlawn
fescue
Traffic tolerance 1-10
Appearance
1-10
Height
inches
Why control weeds?
Reasons to Manage Weeds
Competition
- leading to reduced crop growth and yield
(quantity, quality)
• for water (drought years)
• nutrients (especially nitrogen) –cannot
correct with extra N
• light (viny weeds)
Reasons to Manage Weeds
• Harbor insect and disease pests (dandelion and
tomato ringspot virus, buckhorn plantain/aphids)
• Attract bees (problem for those allergic to bee
stings, concern when insecticides are being
applied)
• Interfere with harvest (rash - poison ivy, spines brambles)
• Allelopathy (natural herbicides) - juglone – black
walnut
• Provide cover for rodents
Tomato ringspot virus and grapes http://www.grapes.msu.edu/ringspot.htm
Transmission of tomato ringspot virus from dandelion via seed
and dagger nematodes. Mountain, W.L. et al. 1983. Plant
Disease 67:867-868.
When seedlings from 5 TmRSV-infected Taraxacum officinale
plants were assayed, an av. 24% were infected, but germination
was unaffected. Xiphinema rivesi (nematode) acquired the virus
from infected plants and transmitted it to healthy seedlings.
Dandelion is a major natural reservoir of the virus in Pa. and the
potential importance of this weed in the epidemiology of
TmRSV-induced orchard diseases (especially Prunus stem
pitting in peach and apple union necrosis in apple) is discussed
Distribution of tomato ringspot virus in dandelion in
Pennsylvania. Powell, C. A. et al. 1984.
Plant Disease 68:796-798.
The percentage of dandelion infection with Tomato ringspot virus
was higher in orchards with Peach stem pitting (29%) than in
either orchards without PSP (7%) or non-orchards (5%). Results
support the hypothesis that TmRSV is initially introduced in an
orchard via either infected nursery stock or dandelion seed and
subsequently becomes established in dandelion and other weeds
over a period of years.
Vegetation Management Plan
• Killed strip within the row to reduce weed
competition
• Mowed (grass) alleyways for erosion
control, drivability soon after rain
Grape Weed Control
• Biological – little available
• Cultural
• Chemical
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
Chemical control
Preemergence 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
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
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
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
Preemergence herbicides for grapes –
annual grasses, small-seeded broadleaf
weeds, suppression of yellow nutsedge
• Solicam (norflurazon)
• Vines must be established 2 years
Pre and early Post control – annual
broadleaf weeds, annual grasses
Goal (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
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.
Chateau (flumioxazin) – grapes
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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
Chateau (flumioxazin) – grapes
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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.
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
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
Preemergence control - annual broadleaf
weeds, annual grasses
Princep (simazine), Karmex (diuron)
• Vines established 3 years
• Inexpensive broadleaf control
• Match rate to soil type
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
Pre – annual grasses, annual broadleaf
weeds
Alion (indaziflam)
• Vines established at least 5 years
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)
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
Postemergence herbicides for
grapes
Chemical control
Postemergence 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)
Postemergence Grass herbicides
Perennial grasses – johnsongrass, quackgrass,
bermudagrass
Annual grasses – crabgrass, foxtails, etc.
• Do not control yellow nutsedge or any
broadleaf weed
• Poast (sethoxydim), Fusilade DX
(fluazifop) – 50 day PHI, Select Max –
nonbearing
• Need to add a nonionic surfactant or crop
oil
Aim (Carfentrazone)
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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,
or fruit of fruit trees.
Can also be used for control of suckers – see label for rates
and directions for this use.
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
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
Alternatives to Rely (glufosinate)
Nonselective
Scythe (pelargonic acid)
• Rapid acting contact
• No effect on underground tissue – rhizomes,
roots, bulbs, etc.
• 3-10% solution, use high spray volumes 75200 gallons spray per acre
• Can be used for sucker control
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
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
Herbicide-Resistant Weeds in Virginia
• atrazine - corn – smooth pigweed, redroot pigweed,
common lambsquarters
• Simazine (Princep) – turf – annual bluegrass
• diclofop – wheat – Italian ryegrass
• sethoxydim – soybean - johnsongrass
• ALS inhibitors (IMIs, Sus – imazethapyr,
nicosulfuron, etc.) – row crops - shattercane, smooth
pigweed, common chickweed
• glyphosate – row crops - horseweed, Palmer
amaranth
• others?