1. Evaluation of Acuron as a new Herbicide for Weed Control in Corn
G.B. Montgomery*, L.E. Steckel, and J.C. Holloway, Jr.

2. Herbicide Resistant Weeds
Herbicide resistant weeds are becoming increasingly common and problematic in all major agronomic crops (Heap 2014)
Diversifying weed management tactics is essential to mitigating this problem
Increasing herbicide modes of action is one effective strategy (Owen et al. 2014)

3. Glyphosate-resistant Weeds

4. Acuron Under development from 2008-2014 by Syngenta
Anticipated release for 2015 growing season
Contains 4 active ingredients with 3 modes of action
Bicyclopyrone
Mesotrione
S-metochlor
Atrazine

5. Acuron Under development from 2008-2014 by Syngenta
Anticipated release for 2015 growing season
Contains 4 active ingredients with 3 modes of action
Bicyclopyrone
Mesotrione
S-metochlor
Atrazine

6. Bicyclopyrone Mode of action: HPPD Inhibitor
Soil and foliar weed control activity
Burndown, PRE, and POST emergence activity
Performance under multiple tillage systems
Complementary control spectrum to mesotrione
Only available as a premix component of Acuron

7. Acuron Formulation: 3.44 lb/gal ZC Rate Structures:
1.25 – 1.5 qt/A in program with mesotrione POST
2.5 – 3.0 qt/A in program w/o mesotrione POST
Active Ingredient
Low Rate (lb ai/A)
High Rate (lb ai/A)
WSSA Group No.
Bicyclopyrone 27
Mesotrione
S-Metolachlor 15
Atrazine 5

8. Acuron Crops Application in field corn: Alone or in tank mixture
PRE and POST use in field corn, silage corn, and seed corn
PRE only use in sweet corn and yellow popcorn
Application in field corn:
28 days prior to planting through 12” corn
Alone or in tank mixture
Atrazine
Paraquat
Glyphosate

9. Justification
Acuron is a new herbicide that could soon be available for producers. Research was conducted to increase knowledge base around the new herbicide and active ingredient.

10. Objective
Compare the efficacy of Acuron to other currently available herbicide premixes.

11. Materials and Methods Locations:
Jackson, TN
Milan, TN
Experimental Design: Randomized Complete Block
Application: CO2 Backpack Sprayer; 15 GPA
Analysis: Proc Mixed, SAS 9.3; α = 0.05

12. Materials and Methods Data Collected: Application Timing:
Injury: 7 DA-A - mid-season
Weed Control: 7 DA-A - mid-season
Application Timing:
Jackson (PRE Study):
Applied immediately after planting
Milan (Program Study):
Application A: immediately after planting
Application B: applied 42 d after planting

13. Materials and Methods Jackson Milan Variety N-74R RR/LL Pioneer 1412HR
Planted
4/1/2014
4/8/2013
Population (seed/A)
30,000
Row Spacing (inches) 30
Weed Species
Annual grasses
Amaranthus palmeri
Ipomoea lacunosa
Amarathus hybridus
Abutilon theophrasti

14. Treatments – Jackson PRE Herbicide Active Ingredient lb ai/A Acuron
bicyclopyrone, mesotrione, S-metolachlor, atrazine
0.037, 0.150, 1.337, 0.625
Acuron + Atrazine
+ atrazine
0.75
Anthem ATZ
atrazine + pyroxasulfone + fluthiacet-methyl
1.00, 0.121, 0.004
Corvus
thiencarbazone-methyl + isoxaflutole
0.033, 0.082
SureStart
acetochlor, clopyralid, flumetsulam
0.938, 0.095, 0.030
Verdict
saflufenacil, dimethenamid-P
0.045, 0.391

15. Treatments - Milan PRE Herbicide Active Ingredient lb ai/A
POST Herbicide
Acuron (Low)
bicyclopyrone, mesotrione, S-metolachlor, atrazine
0.019
0.075
0.669
0.313
Halex GT
S-metolachlor, glyphosate, mesotrione
0.941
0.094
Acuron (High)
bicyclopyrone, mesotrione, S-metolachlor, atrazine
0.037
0.150
1.337
0.625
-None
-Touchdown
-Touchdown Status
-NA
-glyphosate
-glyphosate + dicamba + diflufenzopyr
1.0
0.138
0.053
Acuron + Atrazine
+ atrazine
0.75
None NA
Corvus
Thiencarbazone- methyl + isoxaflutole
0.033, 0.082
Degree
acetochlor
1.947
Roundup P-max
glyphosate
0.773
Lexar
mesotrione, S-metolachlor, atrazine
0.168
1.305
Verdict
saflufenacil, dimethenamid-P
0.045
0.391

16. Weed Control 42 DAT

17. Weed Control 56 DAT

18. Weed Control 70 DAT

19. Weed Control 14 DA-A

20. Weed Control 42 DA-A

21. Weed Control 7 DA-B
_______________________ ________________________________
PRE
PRE fb POST

22. Weed Control 42 DA-B

23. Summary – Jackson
Weed control with Acuron or Acuron + atrazine was similar to that of currently available premix herbicides for corn
Overall weed control from all treatments was similar 56 and 70 DAT
56 DAT weed control was <80% for all treatments, indicating a need for a follow herbicide application

24. Summary - Milan
Residual control from Acuron or Acuron+Atrazine was similar to other PRE herbicides 14 and 42 DA-A
7 DA-B Acuron fb Status + Touchdown, Acuron fb Halex GT, and Degree fb Roundup provided greater control than Acuron, Corvus, or Lexar alone
42 DA-B control from Acuron fb Halex GT was greater than PRE alone treatments and Acuron fb Status + Touchdown provided greater control than Corvus or Lexar alone

25. Conclusion
Acuron provides improved or similar control to currently available premix corn herbicides
Sequential herbicides will still be recommended for season long weed control

26. Acknowledgements West Tennessee Research and Education Center Syngenta
Larry Steckel
Staff
Syngenta
Dr. James Holloway
Dr. Gordon Vail

27. Questions?