1. Weed Control in Strip-Tillage Peanuts
Eric P. Prostko
Extension Weed Specialist
Department of Crop & Soil Sciences
University of Georgia

2. The key to weed management in strip-tillage is to start off with a clean seed-bed at planting!

3. Weeds of Concern

4. Timing of Burndown 2,4-D in February/March for cutleaf eveningprimrose
Smaller weeds
Lower rates
Avoid drift problem
More time to clean out spray tank
3-4 weeks before planting
may still need to do something at planting
Add Gramoxone to residual herbicides

5. Burndown Options Primary Tank-mixes based upon weed species glyphosate
paraquat
Tank-mixes
Valor
2,4-D (rotations)
Aim - ????
based upon weed species

6. Glyphosate vs. Paraquat

7. Effect of glyphosate rate and wheat growth stage on wheat termination – 3 WAT
Stage of Growth
Glyphosate Rate (lb ai/A)
0.75
1.00
Prior to jointing thru 2 nodes 90 95
3 nodes thru last leaf
Early boot thru early heading 75 83
Fully headed to flowering 85
15 trials conducted from averaged across 11 wheat varieties (From LSU Weed Science Group)

8. A new formulation of paraquat 2 lbs ai/gallon “User- friendly”
alginate
alerting agent
purgative
emetic
green dye

9. Gramoxone Max vs. Gramoxone Inteon
G-Max
G-Inteon
Lbs ai/gal
3.0
2.0
Normal Burndown Rates
pts/A
2-3 pts/A

10. What about Temperature?
Depends upon weed and herbicide
Warmer is better
Watch out for sudden temperature drops

11. The influence of air temperature on weed control with glyphosate – 14 DAT
Source: Hager and Spraque, University of Illinois, 2003.

12. The influence of air temperature on weed control with paraquat – 14 DAT
Source: Hager and Spraque, University of Illinois, 2003.

13. DNA’s or Yellow Herbicides
Prowl/Pendimax vs. Sonalan
How do we apply?
Rate
Method
Time
EC or H20
weeds up at application
irrigation or rainfall

14. What have we learned about using yellow herbicides in strip-tillage systems??? (2004-2005)
Rate
1.5 lb ai/A > 1.00 lb ai/A
Formulation
Prowl EC = Prowl H20
Timing
PRE > 4 WBP > 8 WBP
Method
Spray > Fertilizer
Fertilizer Rate
500 lbs/A > 250 lbs/A

15. Strongarm or Valor dryland or irrigated weed species rotational crops
Crop injury risks
Sprayer cleanup
ALS resistance

16. Burndown + PRE Tank-Mixes
Usually not a problem
earlier applied, less control later in season

17. Scout Early After Planting
Do not wait too late!
7-10 DAP
early applications of Gramoxone should control most escapes and set up later POST treatments like Cadre

18. Grass Problems Later Plan on treating with Poast, Select, or Arrow
Texas panicum
crowfootgrass
Plan on treating with Poast, Select, or Arrow
goosegrass

19. Increased Weed Control Costs
1 pt/A ($1.50) + application ($4.00) = $5.50/A
Generic 1 qt/A ($3.75) + application ($4.00) = $8.75/A
Extra 1 pt/A of Prowl = $2.50/A
Extra 8 ozs/A of Gramoxone Inteon ($1.68)
8 ozs/A ($8.75) + 1% v/v ($1.20) + application ($4.00) = $13.95/A
Total = $32.38