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.

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

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

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

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.

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

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

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.

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.

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

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

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

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

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

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

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

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

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

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

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

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

375 WideStrike Cotton Tolerance to Multiple Applications of Ignite b a a a Pounds Lint Cotton Culpepper, York and Steckel 2010

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

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

Photo 5 d after 2 lf application

Photo 5 d after bloom + 2 wk application

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

Developing Integrated Programs Heavy Residue Deep Turn

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

Palmer requires a significant amount of sunlight to emerge!!

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

TREFLAN PRE PPI

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

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