Using Herbicides in Pines and Hardwoods 2016
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Transcript of Using Herbicides in Pines and Hardwoods 2016
Using Herbicides in Pine and Hardwood Management
Kyle CunninghamAssistant Professor of Forestry
Forest Regions in Arkansas
Uplands
Bottomlands
Pine-Hardwood
Mixed, 17%
Bottomland Hardwood,
16%Upland
Hardwood, 39%
Pine, 27%
Vegetative Competition
• Serious competitor to crop trees• Competes for sunlight• Competes for soil water and nutrients• Competes for growing space• Can cause a reduction in growth and
survival
Competition Sources• Common grasses
– Bermuda grass– Bahiagrass– Johnson grass– Fescue– Broomsedge
• Woody species– Persimmon– Blackgum– Sweetgum– Ash– Hickory– Sumac
• Broadleaf weeds– Fireweed– Goldenrod– Curly dock– Horsetail– Ragweed– Smartweed– Pigweed
• Vines– Trumpet creeper– Poison Ivy– Virginia creeper
Options for Competition Control
• Hand weeding• Chainsaw• Shearing• Chopping • Discing• Herbicides
“Just say NO”
• Hand weeding • Chainsaw• Shearing• Chopping• Discing
Importance of Herbicides
Useful on all terrainEase of applicationQuickEconomical vs. mechanical operationsLow disturbance to a forest site
Leaves vegetation and litter
Considerations Prior to Application Crop species Primary competitors Application types Timing concerns Environmental factors Sensitive areas READ THE LABEL!!!!!!!!
Banded versus Broadcast
Pines
• Loblolly• Shortleaf
Herbicide Use
• Site prep• Herbaceous weed control • Woody release• Mid-rotation brush control
Site Prep
• Imazapyr + glyphosate = “Gold standard”• Cost-efficacy is the driving determinant• Rates vary with the species complex on a
site• Triclopyr is used when waxy-leaf species
are a problem• Rates also vary by pine species• Use a nonionic surfactant (NIS) or
methylated seed oil (MSO)– % v/v
Site prep
• Shortleaf = imazapyr + glyphosate• use same materials and rates as for
loblolly, but complete all applications in August-September and plant seedlings in January-February
• If using Velpar L– 4-6 qts./A. depending on soil type and apply late-March-mid-May
Herbaceous Weed Control• Common grasses
– Bermuda grass– Bahiagrass– Johnson grass– Fescue– Broomsedge
• Woody species– Persimmon– Blackgum– Sweetgum– Ash– Hickory– Sumac
• Broadleaf weeds– Fireweed– Goldenrod– Curly dock– Horsetail– Ragweed– Smartweed– Pigweed
• Vines– Trumpet creeper– Poison Ivy– Virginia creeper
Herbaceous Weed Control (HWC)
• Two options -- add to site prep -- post plant application
HWC-Loblolly
• Site prep addition -- 3 oz./A. Oust XP or Spyder OR -- 4 oz./A. Oust Extra (Oust + Escort)• No surfactant
HWC-Loblolly
• Post plant application -- 4 oz/A. Arsenal AC +2 oz/A oust XP – OR -- 4 oz/A. Arsenal AC + 4 oz/A. Oust Extra
• No surfactant
HWC- Shortleaf
• Site prep addition -- 3 oz/A. Oust XP
• No surfactant
HWC- Shortleaf
• Post plant applications -- 4 oz Arsenal AC/A. + 2 oz Oust XP/A. -- OR -- 10-13 oz/A. Oustar
• No surfactant
HWC – Bermudagrass pasture
• Select (clethodim) – 16 oz/A. + NIS – use with single or split application ( fair- good control with single application)
• Fusilade DX ( fluazifop-P-butyl)- 16-24 oz/A. In first application and 12-24oz/A. in second application (add NIS to both) – split applications are required for best results
Woody Release
• Occasional use following burn only, mechanical site prep or no site prep
• Usually in second growing season, but could be in any of first 4 growing seasons
• Choice of materials and rates is now restricted
Woody Release - Loblolly
• 12-16 oz./A. of 4-lb. imazapyr• 12-16 oz/A. of 4-lb imazapyr + 1 oz/A.
Escort XP ( blackberries, winged elm, ash)
Woody Release – Shortleaf
• If hardwoods are a problem on a site, use chemical site prep
Mid-rotation Brush Control (MRBC)
• Applied following first thin to control encroaching hardwoods
• Requires 4-7 years to see full impact• Cost-effective if hardwoods are >5% of
total basal area• Aerial application or ground application
MRBC-Loblolly• 12-16 oz/A. of 4-lb. imazapyr (aerial)—OR– • 12-16 oz/A. of 4-lb. imazapyr + 1 oz/A. Escort
(aerial) – OR –• 24-28 oz/A. Chopper GEN2 (ground) –OR—• 32-40 oz./A. Chopper (ground)– OR—• 4 qts./A. of 4-lb. glyphosate (ground)• Keep spray off foliage of pines when using
ground application• Add NIS
MRBC- Shortleaf
• Lack of research results• 4 qts. of 4-lb glyphosate + NIS ( ground)
Summary• Many products available for all the different
applications• Loss of patent on imazapyr and glyphosate has
drastically changed the economics of herbicide aplication in forestry
• Spectrum of control and cost/acre are and will continue to be primary factors in these decisions
• Sensitivity of shortleaf to imazapyr presents some challenge, but control is still obtainable
Hardwoods
• Oaks – red and white oak groups• Sweetgum• Blackgum• Persimmon• Walnut• Ash?
Herbicide Use
• Site prep• Herbaceous weed control • Timber Stand Improvement “TSI”• Preparation for natural regeneration
harvest
Scenarios for tree planting
Row crop Old fields Cutover sites Natural regeneration
Vegetation Control Options• Mechanical
– Chainsaw– “Mowing”– Bulldozer
• Chemical– Broadcast spray with herbicides– Basal bark applications– Injection
Pines vs. Hardwoods• Comparative caution must be taken when
using herbicides in hardwood settings– Both immediate and residual effects
• Labeled post-plant products for hardwoods– Far and few………
vs =
Old Fields and Row Crop
• Thousands of acres of abandoned agricultural fields are being re-established in hardwood forests annually
• Many of these plantings have been considered unsuccessful
Artificial Hardwood Regeneration
• In bottomland sites competition a major factor
• Lack of implementation of weed control a major factor
New Ideas Impacting Competition Control
• Mixed species stand development• Lack of “usable” site prep herbicides
– Soil active “pine” herbicides• Need for site preparation in hardwood
plantings?• More options for post-planting control
Chemical Options• Single Product• Tank Mixtures• Products used include glyphosate,
imazapyr, triclopyr, dicamba and others• Chemical site prep will not provide
residual herbaceous weed control during the first growing season
Site Preparation – Mowing and Spraying
Competition Sources• Common grasses
– Bermuda grass– Bahiagrass– Johnson grass– Fescue– Broomsedge
• Woody species– Persimmon– Blackgum– Sweetgum– Ash– Hickory– Sumac
• Broadleaf weeds– Fireweed– Goldenrod– Curly dock– Horsetail– Ragweed– Smartweed– Pigweed
• Vines– Trumpet creeper– Poison Ivy– Virginia creeper
Competition Control
• Herbaceous weed control– Pre and post emergent options
• Improper application = high risk of damage• Must use the proper chemical at the
proper time
Application Timing• Pre-emergent = high success
– Avoid damage potential of crop trees• Post emergent is feasible
– Oxyfluorfen• Red oaks
– Clopyralid– Grass herbicides
• Combination of treatments– May need to reduce application rate
May
July
Year After Treatment
Herbicides for Herbaceous Weed Control
• Sulfometuron methyl – Oust XP • Oxyfluorfen – Goal 2XL • Clopyralid – Transline • Glyphosate – Accord XRT II
– Directed spray • Grass Herbicides
– Clethodim – Envoy or SelectMax – Fluazifop-butyl – Fusilade DX – Others
Herbaceous Weed Control• Standard: Oust XP
• 2oz/ac @ 10-15 gpa preemergent• Up to 4oz/ac• Adjust for pH
• High pH (may have adverse affect)• Low pH (may get by with less)
• 5-6ft bands or broadcast
• Other options:• Pre-emergent
• Goal 2XL (64 oz/sprayed ac)• Post-emergent
• Select (8 – 16 oz/sprayed ac)• Fusilade DX (16 – 24 oz/sprayed ac)• Goal 2XL (32 oz/sprayed ac)• Transline (21 oz/sprayed acre)
Always pay attention to label!!!Crop species
Conifer and hardwoodResistant speciesApplication timingSusceptible speciesApplication ratesRestrictive use informationOther information
HWC• We expect:
• Up to 75% greater survival and increased growth using HWC
• More typically – 25 – 30%• Competition for water
• Wet years = less benefit• Dry years = more benefit
• Other considerations:• pH• Resistant species • Onsite water
• Oust XP vs Goal 2XL
HWC Findings
• Many research applications have used HWC (Oust XP)• cherrybark oak, Nuttall oak, Shumard oak, water oak,
willow oak, white oak, post oak, burr oak, overcup oak, swamp chestnut oak, live oak, green ash, common persimmon, red maple, bald cypress, winged elm, sugarberry, sweetgum, and American sycamore (19 spp)
• No phytotoxic effects observed if label rates and application instructions are followed.
• No injury noted from Goal 2XL or grass herbicides in several studies.• Avoid crop oil as an adjuvant
Clearcuts
• Planting in cutover sites can be successful• Harvest needs to be “complete”• Mechanical site prep helpful• Herbaceous and vines are the major
concern– Can spray a pre-emergent herbicide to help
control
Single Stem Injection - TSI
Remove all non-oaks between 1” DBH and 6” DBH
Common Chemicals
• Triclopyr – (Garlon 3a)– 50% concentrate and 50%
water– Apply in a continuous frill
around stem, 1 ml per 3 inches DBH
• Glyphosate – (RoundUp)– 5.4 lbs./gal, 40% percent
concentrate and 60% water– Apply in a continuous frill
around stem– Growing season best
• Imazapyr – Arsenal AC
– Up to 25% concentrate and 75% water
– Apply 1ml solution per 3 inches DBH
– Year round except during green up, fall best
Why Imazapyr?
• Only option for wide spacing injection
• Highly effective on wide spectrum of species
What is “wide spacing injection”?
• 1 hack per 3” diameter at breast height– < 3” dbh = 1 hack– 3-6” dbh = 2 hacks
• 1 ml of 20% Arsenal AC aqueous solution per hack
Herbicide Information Sources
• www.uaex.eduPublications
• Forestry Sections• Pages 179 – 184• HWC• Site prep• Injection• Woody release• Susceptibility
ratings
Herbicide Information Sources• www.clemson.edu
Extension Natural resources
Forestry
• Sections• Herbicide descriptions• HWC• Site prep• Injection• Woody release• Susceptibility ratings
Herbicide Information Sources• Public • Private
– Consulting foresters– Private applicators– Herbicide distribution
companies
Thank You!