turfgrass weed management ii. broadleaf weed control
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Turfgrass Weed Management II. Broadleaf Weed Control. Tim R. Murphy Crop and Soil Sciences The University of Georgia. Broadleaf Control. Most broadleaf control is done with postemergence herbicides. The essential broadleaf herbicides are: Postemergence - growth regulators and sulfonylureas - PowerPoint PPT PresentationTRANSCRIPT
Turfgrass Weed ManagementTurfgrass Weed ManagementII. Broadleaf Weed ControlII. Broadleaf Weed Control
Tim R. MurphyCrop and Soil Sciences
The University of Georgia
Broadleaf ControlBroadleaf Control
Most broadleaf control is done with postemergence herbicides.
The essential broadleaf herbicides are:– Postemergence - growth regulators and
sulfonylureas– Pre and post – atrazine, simazine,
metribuzin.– Pre only - Gallery
Growth Regulator HerbicidesGrowth Regulator Herbicides
Phenoxy Picolinic Acid Benzoic Acid
2,4-D Lontrel Banvel
dichlorprop Turflon D Vanquish
mecoprop
MCPA
Broadleaf HerbicidesBroadleaf Herbicides
There are many growth regulator combinations on the market.
Mixtures of broadleaf-active herbicides tend to control more weed species than each individual component herbicide.
Phenoxy + Dicamba HerbicidesPhenoxy + Dicamba Herbicides
Herbicide 2,4-D MCPP MCPA 2,4-DP dicamba
Weedar 64 X
MCPP-4 X
2 Plus 2 X X
Four Power + X X
Turf D + DP X X
Trimec Classic
X (>) X (<) X
Trimec Southern
X (<) X (>) X
Phenoxy + Dicamba HerbicidesPhenoxy + Dicamba Herbicides
Herbicide 2,4-D MCPP MCPA 2,4-DP
dicamba
Triamine X X X
Triamine II X (>) X (<) X
Tri-Power X (<) X (>) X
Dissolve X X X
Triplet X (>) X (<) X (>)
Triplet Sens. X (<) X (>) X (<)
Phenoxy, Dicamba, Picolinic Phenoxy, Dicamba, Picolinic HerbicidesHerbicides
Herbicide 2,4-D
MCPA clopyralid
triclopyr
dicamba
Lontrel X
Turflon Ester X
Confront X X
Chaser (ester) X X
Chaser II Am. X X
Cool Power (ester)
X (<) X (<) X (<)
HorsePower X (>) X (>) X (>)
Post Herbicide Use GuidelinesPost Herbicide Use Guidelines
Try to avoid spraying warm-season grasses during transition.
Shade grasses are less herbicide tolerant than grasses growing in full sun.
Spray when wind speeds are less than 5 mph.
Post Herbicide Use GuidelinesPost Herbicide Use Guidelines
Avoid stress conditions (> 90 F.)Avoid spring transition on warm-
seasonsRepeat applicationsDo not mow 24 to 48 hours before or after
applicationRainfall and irrigation effects
Post Herbicide Use GuidelinesPost Herbicide Use Guidelines
Do not water for 12-24 hours.
Need a rain free period of at least 6 hours.
Avoid extreme temperatures. Apply when temperatures are between 40 and 80°F.
Examples of Rain-Free PeriodsExamples of Rain-Free Periods
MSMA - 24 hoursTrimec Classic - 24 hoursBasagran T/O - 8 hoursFinale - 4 hoursVantage - 1 hour
Post Herbicide Use GuidelinesPost Herbicide Use GuidelinesAnnual weed control is excellent in the seedling
stage and poor as the weed maturesPerennial weeds are more susceptible in the
Spring or Fall because root reserves are usually depleted and the weed has less recovery potential
Apply to actively growing weeds - the cuticle is more easily penetrated
Sprays give better control than granules.
Post Herbicide Use GuidelinesPost Herbicide Use Guidelines
Repeat applications are most effective for tough perennials.
Apply during good growing conditions when adequate soil moisture is present.
Add a surfactant if called for on label.
Low growing winter annual
lawn burweed
fruit
Pre or postemergence atrazine or simazine in mid-fall. Prompt and Sencor are also effective on tolerant turfgrasses. Repeat applications of 2 or 3-way 2,4-D type herbicides. The key is applying in the fall when the weeds are small
common chickweed
winter annual
winter annualsticky chickweed
henbithenbit
winter annual
Henbit
winter annual
Purple deadnettle
henbit
purple deadnettle
winter annuals
winter annual
hairy bittercress
fruit
winter annual shepherd’s purse
annual or biennial
purple cudweed
winter annual
parsley-piert
winter annual
seedling
corn speedwell
Virginia Virginia buttonweebuttonwee
dd
Difficult to control. Try digging if there are only a few plants. Repeat applications of 3-ways or 2,4-D about 4 weeks apart
are needed for adequate suppression. 2,4-D seems to have the most activity.
Dandelion - PerennialDandelion - Perennial
2,4-D
Trimec
Confront
Drive
wild violet wild violet - -
perennialperennial
Triclopyr-containing formulations (Turflon, Confront) Some think dichlorprop is better on violet. Confront requires careful use in warm-season. Safe in fescue.
white clover - white clover - perennialperennial
Confront, Lontrel and Manor are very effective. Warm-season grasses should be dormant or fully greened-up..
Lontrel and Manor have greater turf safety than Confront. Trimec or other 3-ways are effective. May take two
applications.
winter annual
Spotted burclover
Annual lespedeza
Summer annual
Chamberbitter, niruri
Summer annualBrought to Georgia in ornamental container plants.
•Atrazine or simazine applied twice, 30 days apart.
•Prompt also works well.
•2 or 3-way broadleaf mixtures applied 7 days apart are also effective in tolerant turfgrasses.
prostrate prostrate spurge - spurge - summer summer annualannual
Postemergence: Manor, Sencor, Trimec
Preemergence: Simazine, atrazine, Gallery
summer annual
fireweed
The 2 and 3-way growth regulator herbicides and Manor. Preemergence products are not very effective or provide only short term control.
American burnweed (fireweed)
Pennywort or dollarweed
perennial
•Atrazine or simazine applied twice, 30 days apart.
•Prompt also works well. Image, Drive and Manor.
•2- or 3-way broadleaf mixtures applied 7 days apart are also effective in tolerant turfgrasses.
Dichondra, rhizomatous perennial
Controlled by repeat applications of atrazine, 30 days apart.
2 and 3-way growth regulator herbicides. Confront is a little better than Trimec related compounds.
perennial
ground ivy
buckhorn plantain
perennial
perennial
blackseed plantain
100% Control
Confront 2 pts/acre
Trimec 4 pts/acre
perennial
woodsorrel (Oxalis spp.)
Non-Target PlantsNon-Target Plants
Check for restrictions on the use of herbicides around trees and shrubs.
Be very careful around vegetables and ornamentals with growth regulator herbicides.
Avoid applying dicamba and atrazine under shallow rooted ornamentals such as azalea and rhododendron.
Nonselective ControlNonselective Control
Roundup Pro - Do not tank mix with Reward or Finale if you are trying to control perennials.
Rapid burndown prevents translocation of Roundup through the plant.
Nonselective Broadleaf Nonselective Broadleaf ControlControl
Roundup Pro - slow acting (7-14 days) but provides the best control of perennials.
Reward - fastest burndown, poor perennial control, poor grass control.
Finale - Almost as fast as Reward, will leave a straight edge, very good on white clover and other legumes. Not good on perennials.
Lack of Post Herbicide Lack of Post Herbicide PerformancePerformance
Environmental stressesWeed growth stageRain/irrigation wash-offNo adjuvantPoor spray coverage
Lack of Post Herbicide Lack of Post Herbicide PerformancePerformance
Wrong rateWrong herbicideNo follow-up applicationMowing effects