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Summarizing 5 Years of Summarizing 5 Years of Weed Management Weed Management Research in GeorgiaResearch in Georgia
2001-20052001-2005
Eric P. Prostko
Extension Weed Specialist
and
Tim L. Grey and William K. Vencill
Research Weed Scientists
What have we done?What have we done?2001-20052001-2005
63 field trialsMajor areas of emphasis
RR corn systems LL corn systems Accent vs. Option harvest-aids tropical spiderwort
• In-crop• Post-harvest
other new products• Aim• Callisto, Lexar/Lumax
Should you use the RR corn system?Should you use the RR corn system?
advantages Inexpensive easy Broad spectrum Reduced drift concerns No soil insecticide issues
disadvantages No residual over-reliance on a single
product Herbicide resistance
concerns Volunteer in other RR crops
Texas Panicum Control At Harvest with Single Texas Panicum Control At Harvest with Single or Split Applications of Roundup WM - IIor Split Applications of Roundup WM - II
CN-04-04 (Attapulgus)
UntreatedRoundup WM @ 22 ozs/A
21 DAP
Roundup WM @ 22 ozs/A21 + 35 DAP
124
173
190
0
30
60
90
120
150
180
210
Untreated Single Split
Bu/
A
Corn Yield Response to Single or Split Applications Corn Yield Response to Single or Split Applications of glyphosate (4.5 lb ae/gal) @ 22 ozs/A.of glyphosate (4.5 lb ae/gal) @ 22 ozs/A.
Average of 6 irrigated locations (2003-05)DKC67-60RR
Glyphosate Resistance Around the WorldGlyphosate Resistance Around the World (8 species)(8 species)
rigid ryegrass (1996) goosegrass (1997) horseweed (2000) Italian ryegrass (2001) hairy fleabane (2003) buckhorn plantain (2003) common ragweed (2004) Palmer amaranth (2005)
In Central Georgia
* Can be found in US
Preserving the Value of GlyphosatePreserving the Value of Glyphosate
tank-mix 2,4-D in burndown when glyphosate will be used in-cropConsider paraquat if appropriate
Alternate glyphosate use with other herbicide modes of actionTank-mix with atrazine in corn
Use other practices such as cultivation
Do not allow weed escapes to produce seed
Herbicide programs for managing Herbicide programs for managing glyphosate and ALS-resistant Palmer glyphosate and ALS-resistant Palmer amaranth in Georgia field corn.amaranth in Georgia field corn.
Corn hybrid Preemergence Postemergence Layby as needed
Conventional Prowl2 + Atrazine +Crop Oil
2,4-D5 or Evik
Conventional Bicep II Magnum3, Bullet,Guardsman, Lariat, or
Banvel4,5, Clarity5,or 2,4-D5
2,4-D5or Evik
Liberty Link Dual II Magnum6 orOutlook
Liberty + atrazine7 2,4-D5 or Evik
Roundup Ready Bicep II Magnum3, Bullet, Guardsman, Lariat, or
Lexar at 66% normal rate
glyphosate +atrazine
or Expert8
2,4-D5 or Evik
Accent vs Option SummaryAccent vs Option SummaryTexas Panicum ControlTexas Panicum Control
8 field trials
Accent > Option 9 of 32 comparisons (28% of time)
Option > Accent 1 of 32 comparisons (3% of time)
Accent = Option 22 of 32 comparisons (69% of time)
No statistical differences in corn yield were observed in any trial!
Texas Panicum Control (104 DAT) - IITexas Panicum Control (104 DAT) - IIAccent vs Option - 2004Accent vs Option - 2004
CN-04-04 (Attapulgus)Applied 21 DAPPANTE = 1-2”, 2-4 leaf
Untreated Accent @ 0.67 ozs/AAgrioil @ 1% v/v
Option @ 1.5 ozs/AMSO @ 1.25% v/v
AMS @ 3 lbs/A
Harvest-Aid - 2004Harvest-Aid - 2004
UntreatedUntreated Roundup WM @ 22 oz/ARoundup WM @ 22 oz/A Roundup WM @ 22 oz/ARoundup WM @ 22 oz/A+ Aim 2EC @ 1 oz/A + + Aim 2EC @ 1 oz/A +
COC @ 1% v/vCOC @ 1% v/v
15 DAT
Tropical spiderwort (a.k.a. Benghal dayflower)Tropical spiderwort (a.k.a. Benghal dayflower)Commelina benghalensisCommelina benghalensis
tropical Africa native annual or perennial seeds and rhizomes above and below ground
flowers 1,600 seeds/plant alternate host of southern
root-knot nematode Reservoir for southern
stem blight (white mold)
TSW in GeorgiaTSW in Georgia
* confirmed in 29 counties by GA Dept. of Ag and UGA in 2004 (blue)
* identified in 4 morecounties in 2005 (black)
Tropical Spiderwort Control in Field Corn - Tropical Spiderwort Control in Field Corn - 20052005
UntreatedUntreated(166 bu/A)(166 bu/A)
Aim 2EC @ 1.5 ozs/AAim 2EC @ 1.5 ozs/ADual Magnum 7.62EC @ 1.33 pt/ADual Magnum 7.62EC @ 1.33 pt/A
Herbimax @ 1% v/vHerbimax @ 1% v/v(168 bu/A)(168 bu/A)
34 DAT34 DAT $24/A treatment cost (excluding application)
Post-Harvest – 2005Post-Harvest – 20052,4-D (1 pt/A) + Dual Magnum (12 ozs/A) + COC (1% v/v)2,4-D (1 pt/A) + Dual Magnum (12 ozs/A) + COC (1% v/v)
22 DAT22 DAT 43 DAT43 DAT 54 DAT54 DAT
* **
Grady County $12/A Treatment cost (excluding application)
The FutureThe Future
Liberty Link?Products labeled but
not yet tested in GA Impact (AmVac)Stout (DuPont)
New products being developedKIH-485
Post-harvest for tropical spiderwort
others??
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