Curtis Rainbolt

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Herbicides for Sugarcane

• Curtis Rainbolt
• Everglades REC

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Herbicide Basics

• What is the application timing
• Common sugarcane timing
• PRE
• Applied prior to weed and crop emergence
• Generally soil active herbicides (some
  exceptions)
  
• POST
• Applied after weeds have emerged
• Can be early, mid, late
• Generally over-the-top
• Generally more foliar active herbicides

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Herbicide Basics

• What is the application timing
• Common sugarcane timing
• Post-Direct/Lay-by
• Applied after sugarcane is fairly large
• Direct herbicide at base of plant
• Generally for herbicides that cause crop injury
• Can be foliar or soil active (or both)
• Non-Crop/Fallow
• Generally foliar active
• Can help with hard to control weeds

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PRE Herbicides
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Atrazine

• Backbone of sugarcane weed control
• Used both PRE and POST
• PRE
• Good soil activity (2-4 qt/A)
• Controls most broadleaves
• Suppress/control many grasses
• Activity begins to fade 3-5 weeks after
  application
  
• Broadleaf activity last longer than grass
  activity
  

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Evik (Ametryn)

• Generally applied POST, but some PRE
• Controls many small grasses and broadleaves
• Needs to be less than 4 inches
• Less than 3 inches for alexandergrass
• Crop injury
• More common with higher rates and warmer
  temperatures
  

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Evik (Ametryn)

• Rates
• 0.5-1.5 lb/A (labeled)
• Lower rates often used
• Efficacy?
• Tankmixture
• Often tank mixed with atrazine (2-4 lb/A) at 0.25
  to .75 lb/A

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Prowl H2O and Prowl 3.3 (Pendimethalin)

• Used on moderate acreage
• Excellent grass control
• Can be season-long under good conditions
• Not so good on broadleaves
• Tank-mix with Sencor (metribuzin) helps
• Still may need follow-up for spiny amaranth

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Prowl (Pendimethalin)

• Challenges
• Needs rainfall/soil moisture for activity
• Can be good when soil is dry
• More consistent when soil moisture is good
• Rates
• Sand
• 2.4-3.6 qt/A
• Muck
• 2.4-4.85 qt/A

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Prowl Sencor

• Good broad spectrum PRE program
• Muck soil only!!!
• Ideally, dont cultivate if there arent weeds
• Some broadleaves can come through
• Spiny pigweed
• Expensive
• Can be very good with good soil moisture
• Rates
• Prowl (4 qt/A)
• Sencor (1 lb/A)

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K4

• Registered for FL sugarcane in 2005
• Mixture of hexazinone (Velpar) and diuron
  (Karmex)
  
• Applied at 2-4 lbs/A
• Higher rates for muck soils, lower on sand
• Good control of many grass and broadleaf weeds
• Can go out early POST
• Apply to cane less than 18 inches tall

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Diuron(Karmex/Direx/Etc)

• Not used much
• Sand soils (binds very strongly on muck)
• Better control of broadleaves than grass
• Not much experience
• Crop injury?
• Rate
• 1.6 lb/A PRE

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Roundup Ultramax(Glyphosate)

• MUST BE APPLIED PRIOR TO CANE EMERGENCE!!!!!!!!
• Excellent control of emerged weeds
• Excellent control of sugarcane if emerged!
• Timing is very, very critical
• Controls some hard to manage species
• Bermudagrass
• Paragrass
• Rate
• 3.25-4 qt/A

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Valor(Flumioxazin)

• PRE/POST-Direct
• Good broadleaf control PRE
• Grass control has been variable
• Active POST on small grass and broadleaves
• High levels of burn on sugarcane
• Post-direct only
• Cannot be applied over the top of sugarcane

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POST Herbicides
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Atrazine

• POST
• Use with crop oil concentrate
• Rate still 2-4 qt/A
• Controls many small broadleaves
• Grass needs to be small
• 3 inches of less is ideal
• Provides residual activity

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Envoke (Trifloxysulfuron)

• Applied at 0.3 to 0.6 oz/A
• POST, ratoon sugarcane only
• Excellent nutsedge product
• Good control of small broadleaves
• Controls some small grasses
• Excellent on alligatorweed, spiny amaranth
• Looks good in combination Asulox/Asulam at 0.5
  gallon/A
  
• Good, wide spectrum treatment

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2,4-D Amine

• Very versatile, useful product
• Controls most broadleaves
• Can use lower rates on smaller weeds
• Can suppress nutsedge growth
• Probably not long-term control
• Alligatorweed activity can be good
• Need good conditions for best control

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2,4-D Amine

• Challenges
• Can drift and volatilize
• Major problems!!!!
• Follow the Florida Organo-Auxin Rule
• No volatile formulations (esters)
• Application restrictions based on wind speed
• Also distance from sensitive crops
• http//edis.ifas.ufl.edu/WG051

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2,4-D Amine

• Rates
• 0.5 to 2.0 lb ai/A
• Note rates in ai due to many formulations
• Lower end will control many small weeds
• Higher rates for alligatorweed, large weeds

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Asulox(Asulam)

• Excellent POST grass herbicide
• Controls most common grasses
• Size of weeds is important
• Can use 6 pt/A if grass is 6-8 inches or less
• Preferably less!
• Use 1 gal/A (8 pt) is grass is greater than 8
  inches
  
• Use a surfactant (0.25 v/v) or COC (1 v/v)

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Asulox(Asulam)

• Challenges
• Good spray coverage is very important
• Many control issues relate to coverage
• Use the proper rate
• If its 6 inches today, it will probably be 8
  inches next week
  
• Slow activity
• Need to be patient
• Injury
• We can see burning to leaves at higher rates
• Can use a directed application

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Asulox(Asulam)
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Evik (Ametryn)

• Controls many small grasses and broadleaves
• Needs to be less than 4 inches
• Less than 3 inches for alexandergrass
• Directed application
• Injury will be seen on treated foliage
• Use surfactant at 0.5 v/v
• Rates
• 0.5-1.5 lb/A
• Lower rates often used

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Sempra, Sandea (Halosulfuron)

• Excellent nutsedge control
• Yellow and purple (4-12 inch ideal)
• Works best under good moisture conditions
• Controls some small broadleaves
• Small pigweed, ragweed (less than 4 inches)
• Use surfactant or COC
• 0.25-0.5 v/v surfactant or 1 COC v/v
• Rate
• 1 to 1.33 oz/A

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Fallow Land Treatments
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Glyphosate

• Excellent control of emerged weeds
• Controls many hard to manage species
• Bermudagrass
• Paragrass
• Napiergrass
• Nutsedge (better on yellow)
• Many, many others

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Take Home

• Always follow the label!!!
• Several effective herbicides
• Identify weed spectrum
• Apply correct rate
• Apply to correct weed size
• Let the herbicide work!
• We will hopefully have more options in the future!