Title: Comparison of Conventional, Roundup Ready, and Liberty-Link Cotton Weed Management Programs in Two Tillage Systems
1Comparison of Conventional, Roundup Ready, and
Liberty-Link Cotton Weed Management Programs in
Two Tillage Systems
Michael Patterson, Bob Goodman and Dale
Monks Auburn University Wilson Faircloth
USDA-ARS, Dawson Ga.
2Alabama Cotton
- In Alabama and most of the southeast, Roundup
Ready Cotton comprises 90 to 95 of the acreage. - The remainder of cotton acreage is planted in
conventional (non-transgenic) or Liberty-Link
varieties. - Over 75 of Alabama cotton is grown in some form
of reduced tillage.
3Research Objectives
- Evaluate cotton production in tilled and reduced
till systems using Roundup Ready, Liberty Link,
and conventional weed management programs. - Evaluate the economic viability of each
tillage/weed management system. - Philosophize on the implications of the data.
4Materials and MethodsLocations
Tennessee Valley Research and Extension Center
Belle Mina (Decatur clay loam)
Wiregrass Research and Extension
Center Headland (Dothan sandy loam)
5Materials and MethodsExperimental Particulars
- Time frame 2005, 2006
- Varieties FM 966, FM 960 RR, FM 966 LL
- Conventional and reduced tillage.
- Six Treatments
- Replicated four times
- Plot Dimensions both north and south AL four
rows by 40 long, each plot separated by four
border rows
6Materials and MethodsExperimental Particulars
- Tractor mounted sprayer used 15 GPA.
- Conventional tillage north AL disk 2X,
roterra. south AL subsoil, disk, roterra. - Reduced tillage north AL notill into wheat,
south AL strip till into wheat. - Soil types north AL clay loam. south AL
sandy loam
7Tillage/Herbicide Treatments
8Costs of Tillage/Weed Systems( per acre)
9Effect of Herbicide System Fiber Strength and
Percent Lint (north Alabama)
Herbicide System Strength of Fiber g/tex Percent Lint 2006
RR variety 29.7 44.4
LL variety 31.7 43.1
CV variety 31.7 44.6
LSD (.05) 0.7 0.8
10Effect of Tillage on Broadleaf Weed Control
(north Alabama)
Tillage System Control 2005 Control 2006
Reduced till 98 93
Conv till 98 84
LSD (.05) NS 5
11Effect of Tillage on Cotton Yield and Economic
Return (south Alabama)
Tillage System Lint Lb/A /System
Reduced till 1576 700
Conv till 1425 625
LSD (.05) 105 ----
12Effect of Herbicide System on Weed Control and
Cotton Yield (south Alabama)
Variable RR LL CV LSD .05
Grass 95 94 89 3
Brdlf 94 89 85 6
Lint /A 1564 1461 1326 125
Lint 41.6 39.4 40.8 0.9
/System 686 649 578 ----
13SUMMARY (north Alabama)
- No yield differences due to herbicide/tillage
system in. - Decrease in late season broadleaf weed control
for Conventional till in 2006. - Slight and inconsequential differences in
strength and turnout between varieties.
14Summary (south Alabama)
- Greater yield in strip till than in conventional
till in both years. - Greater yield in RR and LL systems than in
conventional herbicide systems in both years. - Strip till returned 75.00 per acre more than
conventional on average. - RR and LL returned 108.00 and 71.00 more per
acre respectively than conventional herbicide
system.
15Implications of data
- Probable reduction in economic return if south AL
cotton growers return to conventional tillage and
conventional herbicide technology. - New post-emergent herbicide technology with
activity on pigweed is needed in light of the
recent discovery of glyphosate and ALS resistant
pigweed biotypes.
16Support
- Researchers gratefully acknowledge the financial
assistance of Cotton Incorporated and Alabama
cotton growers in conduction of this research. - Reseachers also gratefully acknowledge the
support of Alabama Agricultural Experiment
Station personnel at the Tennessee Valley and
Wiregrass Research and Extension Centers.
17Questions?
Q