1. 2011 Cotton County Weed Meetings
2005 – 2 counties
2006 – 7 counties
2007 – 10 counties
2008 – 18 counties
2009 – 13 counties
Counties confirmed with glyphosate-resistant Palmer amaranth.

2. What makes Palmer a super weed?
Herbicide resistance!
Growth rate!
Large stature!
Competitive ability!
Reducing harvest efficacy!
Seed production!
Rapid spread! 2

3. 2011 Focus Warrant vs Dual Magnum Reflex Valor plant-back
Ignite/Palmer size
5. Recommended herbicide programs
6. Widestrike cotton
7. Cover crops/deep turning
8. Monsanto rewards program 3

4. Warrant vs Dual Magnum
Dual Magnum: apply overtop of completely emerged cotton until 100 days of harvest
Warrant: apply when cotton is completely emerged through first bloom 4

5. Palmer control from acetochlor, S-metolachlor, and metolachlor
Palmer control from acetochlor, S-metolachlor, and metolachlor. Macon Co., GA 2009.
80 a
77 a
50 c
Warrant
3 pt
S-metolachlor
(Dual Mag, 1 pt)
metolachlor
(Parrlay, 1 pt)
No Palmer up at time of application. Layby of RU + Direx applied 19 d after POST.

6. WeatherMax + Dual Magnum 1 pt/A WeatherMax + Warrant 3 pt/A

7. Reflex Fields heavily infested with resistant Palmer
1. Typically 16 oz/A but 12 oz/A on sandier soils
2. Always tank mix with herbicide partner
3. Today only labeled PRE 7

8. Percent Palmer Control, 2010. TyTy, GA. 38 DAT.
92 b
80 c
3 d
PPI
Field cultivator
PPI
Disk
PRE
PPI
Rototiller
Reflex applied at 1 pt in combination with Prowl.

9. Percent Palmer Control, 2010. TyTy, GA. 38 DAT.
92 b
80 c
no activation no control
3 d
PPI
Field cultivator
PPI
Disk
PRE
PPI
Rototiller
Reflex applied at 1 pt in combination with Prowl.

10. Change in Valor Label?
Strip-Till Production: Apply Valor at least 7 d ahead of planting as long as the strip operation occurs between applying Valor and planting.
No Till Production:
1. <30% residue: 28 days and 1 inch rain
2. >30% residue: 21 days and 1 inch rain 10

11. Controlling GR Palmer amaranth in RR conventional IRRIGATED cotton
PRE
POST1
1-lf cotton
POST 2
5-6 lf cotton
Layby
1. Reflex + diuron
2. Reflex + Prowl
3. Reflex + diuron
4. Reflex + Prowl
5. Reflex + Staple
6. diuron + Staple +
Prowl
RU + Staple
(emerged pigweed)
RU + Dual or Warrant
diuron +
MSMA

12. Figure 2. Early topical applications with residual needed before Palmer emerges in RR cotton!!
POST 1 = 25 days after PRE
POST 1 = 17 days after PRE
Prowl + Reflex PRE, Roundup + Dual Magnum POST 1, Roundup + Warrant POST 2, Direx + MSMA layby

13. Controlling GR Palmer amaranth in RR conservation tillage IRRIGATED cotton. 2011.
PREPLANT and PRE
POST1
1-lf cotton
POST 2
5-6 lf cotton
Layby
1. diuron preplant, Reflex + Prowl PRE
2. Valor preplant, Staple + diuron + Prowl PRE
RU + Staple
(emerged pigweed)
RU + Dual or Warrant
diuron +
MSMA

14. Controlling 5 inch Glyphosate-Resistant Palmer amaranth at Burndown
Controlling 5 inch Glyphosate-Resistant Palmer amaranth at Burndown. Macon Co., GA 2008.*
94 a
87 b
70 b
58 b
0 c
Roundup
Parazone
1.33 pt
Parazone +
2,4-D (1.5 pt)
Parazone +
Clarity (8 oz)
Parazone +
Diuron (1.8 pt)
+COC

15. Palmer control at planting, burndown applied 17 d earlier. Macon Co
Palmer control at planting, burndown applied 17 d earlier. Macon Co., GA 2009.
99 a
90 b
Valor preplant
Direx preplant

16. Dryland Conservation Tillage
Prowl + Reflex PRE
Roundup + Dual POST
Diuron + MSMA PD
Prowl + Reflex PRE
Ignite + Dual POST
Diuron + MSMA PD

17. Palmer response to Ignite
WATER VOLUME AND NOZZLE TYPE IS CRITICAL
Do not apply within an hour of sunrise
MUST KILL IT WITH THE FIRST APPLICATION

18. Application Timing is Critical in LL Cotton
3” Palmer: 29 to 32 oz/A = >98% control
3-4”: 36 oz/A = 88 to 100% control
4-6” Palmer: 43 oz/A = 70 to 100% control
>6” Palmer: 43 oz and get the hoes ready

19. Controlling GR Palmer amaranth in LL conventional DRYLAND cotton.
PREPLANT and PRE
POST1
1-lf cotton
POST 2
6-7 lf cotton
Layby
1. diuron + Reflex
2. Cotoran + Reflex
3. Prowl + Reflex
4. Diuron + Staple
5. Cotoran + Staple
6. Diuron PRE
7. Cotoran PRE
8. Treflan PPI
Ignite 29 oz + Dual Mag.
Ignite 29 oz
diuron +
MSMA

20. Hooded Spray or Layby Rig
Diuron + MSMA + COC
Suprend + MSMA + COC
Layby Pro + MSMA + COC
Gramoxone + diuron + COC
(still have to direct to row)

21. Phytogen Widestrike Cotton
Confers tolerance to Ignite
Tolerance not complete; injury will occur and yield loss can occur if you don’t know what you are doing.
According to EPA, Ignite can be applied to widestrike cotton.
However, grower is liable as neither Bayer, Dow, or UGA is recommending or warranting the use of Ignite on Widestrike cotton 21

22. 375 WideStrike Cotton Tolerance to Multiple Applications of Igniteb a a a
Pounds Lint Cotton
Culpepper, York and Steckel 2010

23. 375 WideStrike Cotton Tolerance to Multiple Applications of Ignite
Ignite 2 lf, 7 lf, bloom b
Ignite 2 lf and 7 lf a
No Ignite a
Pounds Lint Cotton

24. 375 WideStrike Cotton Tolerance to Multiple Applications of Ignite
Ignite 2 lf, 7 lf, bloom b
Ignite 2 lf and 7 lf a
No Ignite a
Pounds Lint Cotton

25. Photo 5 d after 2 lf application

26. Photo 5 d after bloom + 2 wk application

27. 54% of cotton handweeded 2010; 53% of cotton handweeded in 2009
Integrating Your Program
York 2010
54% of cotton handweeded 2010; 53% of cotton handweeded in 2009 27

28. Developing Integrated Programs
Heavy Residue
Deep Turn

29. No Herbicide Treatment
Number of Palmer Amaranth Plants During Early Season. Macon Co., Georgia 2008.*
No Deep Tillage
Deep Turn
No Herbicide Treatment

30. Palmer requires a significant amount of sunlight to emerge!!

33. GR Palmer amaranth control by tillage, cover crop residue, and herbicides. At harvest.*%
59 c
Inversion + rye
Weeds
Deep inversion
Rye
*RR System: Diuron + Reflex + Staple fb Roundup + Parrlay fb Direx + MSMA

34. TREFLAN
PRE
PPI

35. Valor 2 oz OR Reflex 1 pt = ($4.00)
Monsanto’s Roundup Ready Cotton Performance Roundup Ready Flex Cotton (Up to $20)
Valor 2 oz OR Reflex 1 pt = ($4.00)
Cotoran, Cotton Pro, Caparol, diuron 2 pt = ($3.00)*
Warrant 3 pt or Dual Magnum 1 pt = ($4.50 or $3.00)
Gramoxone Inteon 2 pt = ($1.00)
*Will pay on 2 applications

36. 2,4-D and Clarity Resistant Cotton In Development
2,4-D resistant cotton
2,4-D sensitive cotton 36