1. Herbicides for Sugarcane
Curtis Rainbolt
Everglades REC

2. 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

3. 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

4. PRE Herbicides

5. 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

6. 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

7. Evik (Ametryn) Rates Tankmixture: 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

8. 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

9. 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
qt/A
Muck
qt/A

10. Prowl + Sencor Good broad spectrum PRE program Rates Muck soil only!!!
Ideally, don’t cultivate if there aren’t 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)

11. 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

12. 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

13. 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
qt/A

14. 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

15. POST Herbicides

16. 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

17. 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

18. 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

19. 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

20. 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

21. 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)

22. Asulox (Asulam) Challenges Good spray coverage is very important
Many control issues relate to coverage
Use the proper rate
If it’s 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

23. Asulox (Asulam)

24. 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
lb/A
Lower rates often used

25. 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
% v/v surfactant or 1% COC v/v
Rate
1 to 1.33 oz/A

26. Fallow Land Treatments

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

28. 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!