impact of tillage on the control of glyphosate-resistant palmer amaranth
DESCRIPTION
Impact of Tillage on the Control of Glyphosate-Resistant Palmer amaranth. Culpepper, Kichler, York. Irrigated or Dryland. Production Practices. Irrigated - conventional? Irrigated – conservation tillage? Dry land - conventional? Dry land – conservation tillage?. - PowerPoint PPT PresentationTRANSCRIPT
Impact of Tillage on the Control of Glyphosate-Resistant Palmer amaranth.
Culpepper, Kichler, York
Irrigated
or
Dryland
Production Practices
1. Irrigated - conventional?
2. Irrigated – conservation tillage?
3. Dry land - conventional?
4. Dry land – conservation tillage?
May 2008 Rainfall Distribution in Tifton (CPES)
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Day
Dryland crops planted before May 9 or after May 16 did not get enough rain to activate residual herbicides!!!First rainfall event > 0.5” in June occurred on June 15 (1.03”)
0.33”
0.02”
1.4”
Herbicide activated
Dry Land Management Tactics
1. Tillage
2. Cover Crops
3. Ignite-based programs
4. Various mixtures of all of these tactics
Objective
Determine the impacts of deep turning, incorporating a yellow herbicide, and cultivation on the management of glyphosate-resistant Palmer amaranth.
Experimental Locations: Macon County, 2008
Experiment 1:
Factorial:
2 deep tillage options
4 herbicide systems
Two Deep Tillage Options
deep turn or no deep turn
All land was disked prior to planting
Four Herbicide Options
1. no herbicide
2. WMax: 1, 5, 13 lf cotton
3. Prowl H20 + Reflex PRE;
WMax + Dual Magnum POST 5 lf;
Direx + MSMA LPD 13 lf
4. Treflan PPI;
Reflex PRE;
WMax + Dual Magnum POST 5 lf
Direx + MSMA LPD 13 lf
Herbicides and Rates
2.0 pt/AProwl H20
1.5 pt/ATreflan
1.0 pt/AReflex
22 oz/AWeatherMax
1.0 ptDual Mag.
PPI or PRE POST
Layby
Direx 2 pt + MSMA 2 lb
Experiment 1: Methods
Plot size: 4 rows by 30 feet
Herbicide applications: 15 GPA
Rainfall: Once inch occurred 5 d after planting
Visual ratings: early and late-season
Harvest: one-row cotton picker
No Deep Tillage Deep Turn
No Herbicide Treatment
Number of Palmer Amaranth Plants During Early Season. Macon Co., Georgia 2008.*
*System included Reflex PRE; WMax + Dual Mag. POST.
Percent glyphosate-resistant Palmer amaranth control at layby. Macon Co., GA. 2008.*
0
20
40
60
80
100
53 d
Prowl system*
None Prowl system*
Treflan system*
Treflan system*
No Deep Tillage
10 e
89b
100 a
67c
Deep Tillage
RU 2X RU 2 X
100 a
100 a
*System included Reflex PRE; WMax + Dual Mag. POST; Direx + MSMA directed.
Percent glyphosate-resistant Palmer amaranth control at harvest. Macon Co., GA. 2008.*
0
20
40
60
80
100
0 c
Prowl system*
None Prowl system*
Treflan system*
Treflan system*
No Deep Tillage
0 c
79b
90 a
0 c
Deep Tillage
RU 3X RU 3 X
98 a
94 a
No Deep Tillage Deep Turned
Prowl H20 + Reflex PRE;
WeatherMax + Dual Magnum POST; Direx + MSMA Layby
*System included Reflex PRE; WMax + Dual Mag. POST; Direx + MSMA directed.
Seed Cotton Yield. Macon Co., GA. 2008.*
0
300
600
900
1200
1500
1800
0 c
Prowl system*
None Prowl system*
Treflan system*
Treflan system*
No Deep Tillage
0 c
1170 b
1570 a
0 c
Deep Tillage
RU 3X RU 3 X
1430 a
1550 a
Experiment 2: Methods
Plot size: 8 rows by 50 feet
Herbicide applications: 15 GPA
Rainfall: Once inch occurred 5 d after planting
Visual ratings: early and late-season
Harvest: one row cotton picker
Experiment 2: Treatments
1. Prowl H20 + Reflex PRE;
WMax + Dual POST;
Direx + MSMA LPD
2. Treflan PPI;
Reflex PRE;
WMax + Dual POST;
Direx + MSMA LPD
with and without cultivation
Percent glyphosate-resistant Palmer amaranth control at harvest. Macon Co., GA. 2008.*
0
20
40
60
80
100
78 a
88 a
Treflan
system*
Prowl
system*
*System included Reflex PRE; WMax + Dual Mag. POST; Direx + MSMA directed.
Percent glyphosate-resistant Palmer amaranth control at harvest. Macon Co., GA. 2008.*
0
20
40
60
80
100
78 b
+ Cultivation
88 a
Treflan
system*
Prowl
system*
*System included Reflex PRE; WMax + Dual Mag. POST; Direx + MSMA directed.
89 a95 a
Prowl System + Cultivation
Seed Yield as Impacted by Cultivation. Macon Co., GA. 2008.*
0
600
1200
1800
2400
1840 c
+ Cultivation
2050 b
Treflan
system*
Prowl
system*
*System included Reflex PRE; WMax + Dual Mag. POST; Direx + MSMA directed.
2000 b
2275 a
Summary
1. Deep turning reduced the number of Palmer amaranth that emerged at 1 month after planting by 60%.
2. Deep turning improved Palmer control of the Prowl PRE systems by 15% at harvest and increased yield 19%.
Summary
3. When not deep turning the land, incorporating the yellow herbicide improved control by 11% at harvest and increased yield 26%.
4. Cultivation improved control in the Prowl system by 11% and increased yield 6 to 10% in the Prowl or Treflan system
Conclusion
Deep turning land, incorporating the yellow herbicide, and cultivation can all be used to improve control of glyphosate-resistant Palmer amaranth in dry-land Roundup Ready cotton production.
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