2001 Cotton Production Workshop
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Transcript of 2001 Cotton Production Workshop
2001 Cotton Production Workshop
Waiting until spring to control weeds
glyphosate or paraquat
PLUS
Aim, Caparol, Clarity, Direx, Harmony Extra, Goal, Resource, Valor, and 2,4-D
Glyphosate Tank Mixes on Cutleaf Eveningprimrose. GA & NC data.
0
20
40
60
80
100
Gly alone
Gly + 1 pt 2,4-D
% c
ont r
o l,
30-4
0 da
y s
58
96
Average of 12 trials, 1999-2001.
Roundup UltraMax 1.6 pt
14 days after treatment 28 days after treatment
Glyphosate Tank Mixes on Cutleaf Eveningprimrose. GA & NC data.
0
20
40
60
80
100Gly alone
Gly + 1/2 ozHarmony ExtraGly + 1 pt 2,4-D%
con
t ro l
, 30
-40
day s
58
96
Average of 12 trials, 1999-2001.
63
Glyphosate Tank Mixes on Cutleaf Eveningprimrose. GA & NC data.
0
20
40
60
80
100Gly alone
Gly + 2-3 ozResourceGly + 1 pt 2,4-D%
con
t ro l
, 30
-40
day s
50
97
Average of 4 trials, 1999-2001.
63
Glyphosate Tank Mixes on Cutleaf Eveningprimrose. GA data.
0
20
40
60
80
100Gly alone
Gly + 1 ozValorGly + 1 pt 2,4-D%
con
t ro l
, 30
-40
day s
47
97
Average of 1 trials, 2001.
80
• flumioxazin
• change from WDG to WP
• 1 to 2 oz/A mixed with glyphosate– much quicker burndown– residual activity if contacts soil (good for pusley)– enhanced geranium, radish, and primrose control
Valor for Burndown
Glyphosate Tank Mixes on Cutleaf Eveningprimrose. GA & NC data.
0
20
40
60
80
100Gly alone
Gly + 2 ozValorGly + 1 pt 2,4-D%
con
t ro l
, 30
-40
day s
63
97
Average of 8 trials, 1999-2001.
84
Roundup UltraMax 1.6 pt + Valor 1 oz
14 days after treatment 28 days after treatment
0
20
40
60
80
100 Gly alone
Gly + 1 pt Goal
Gly + 1 pt 2,4-D
Average of 5 trials, 1999-2001.
% c
ont r
o l,
30-4
0 da
y s
65
98
74
Glyphosate Tank Mixes on Cutleaf Eveningprimrose. NC data.
0
20
40
60
80
100 Gly alone
Gly + 1/2 pt Clarity
Gly + 1 pt 2,4-D
Average of 6 trials, 1999-2001.
% c
ont r
o l,
30-4
0 da
y s
62
9787
Glyphosate Tank Mixes on Cutleaf Eveningprimrose. NC data.
0
20
40
60
80
100 Gly alone
Gly + 2/3 ozAim
Gly + 1 pt 2,4-D
Average of 3 trials, 1999-2001.
% c
ont r
o l,
30-4
0 da
y s
47
97
60
Glyphosate Tank Mixes on Cutleaf Eveningprimrose. GA & NC data.
0
20
40
60
80
100 Gly alone
Gly + 1 ptDirex
Gly + 1 pt 2,4-D%
con
t ro l
, 30
-40
day s
47
95
64
Average of 1 trials, 2001.
Glyphosate Tank Mixes on Cutleaf Eveningprimrose. GA data.
Relative Response of Cutleaf Eveningprimrose to Glyphosate Tank Mixes.*
0
0.5
1A
lone
Har
mon
y G
T
Aim
Har
mon
yE
xtra
Goa
l
Res
ourc
e
Val
or
Cla
rity
2,4-
D
*Estimates based on GA and NC data from 1999 to 2001.
Roundup
+ Direx Roundup
On farm, Grady County, 2001.
Roundup UltraMax (1.6 pt) + 1.5 pt Caparol
Wheat Response to Glyphosate Applied Alone and in Mixture with Caparol. Ponder Farm, 2001; 16 DAT.
0
20
40
60
80
100Boa alone
+ 1 oz Valor
+ 2 oz Valor
+ 4 oz Resource
+ 2/3 oz Aim
+ 1 pt Direx
+ 1 pt Caparol
+ 1 pt 2,4-D
+ 1/2 oz Harmony Ex
% c
ont r
o l,
30-4
0 da
y s
55
71
46
5970
54
96
71
Paraquat Tank Mixes on Cutleaf Eveningprimrose. GA data.
LSD = 13
68
Average of 1 trials, 2001.
Summary - Cutleaf Eveningprimrose
1. 2,4-D, glyphosate + 2,4-D, paraquat + 2,4-D
2. glyphosate + Valor or Clarity
3. paraquat + Direx, Valor, Harmony Extra or glyphosate + Aim, Caparol, Direx
Wild Radish
0
20
40
60
80
100 Roundup UltraMax
+ 1 oz Valor
+ 2 oz Valor
+ 4 oz Resource
+ 2/3 oz Aim
+ 1 pt Direx
+ 1 pt Caparol
+ 1 pt 2,4-D
+ 1/2 oz Harmony Ext
% c
ont r
o l,
30-4
0 da
y s
7081
71 73 7769
9585
Tank Mixes with Glyphosate on Wild Radish. GA data, Tift County, 2001.
LSD = 12
93
0
20
40
60
80
100Boa alone
+ 1 oz Valor
+ 2 oz Valor
+ 4 oz Resource
+ 2/3 oz Aim
+ 1 pt Direx
+ 1 pt Caparol
+ 1 pt 2,4-D
+ 1/2 oz Harmony Ext.
% c
ont r
o l,
30-4
0 da
y s
67 70 68 67
87
67
99
76
Tank Mixes with Paraquat on Wild Radish. GA data, Tift County, 2001.
LSD = 12
99
Summary - Wild radish
1. glyphosate + 2,4-D, Harmony Extra
paraquat + 2,4-D, Direx, Harmony Extra
2. glyphosate + Valor, Direx
3. glyphosate
paraquat + Valor
• 2,4-D = preferably 45 days
• Aim = nothing on label
• Clarity = 21 d after 1” rainfall
• Direx = 15 d prior to planting
• Goal = 30 d or at least three 0.25” rainfalls
• Harmony Extra = 45 d prior to planting
• Valor = 30 d prior to planting
Plant Back Restriction for Burndown Herbicides
0
20
40
60
80
100
none 21 14 7 0
Cotton Injury to Valor Applied Less Than 30 Days Before Planting. TyTy, 2001
% c
otto
n in
jury
, 18
DA
P
days before planting
*Irrigated at cotton emergence. No weeds present at time of application.
Georgia Cotton - Cultivar Selection*
• 86.9% transgenic; 12.1% conventional
• 40.8% Roundup Ready
• 41.5% stacked gene
• 4.6% Bollgard
*USDA Agricultural Marketing Service Survey, August 2001.
The first 4 to 5 weeks of cotton development is the most critical.
Effect of PRE Herbicides on RR Seedcotton Yield.1
0
300
600
900
1200
1500
1800
lb/A
1 OT 2 OT
1490 a
1070 b
1998 1999
1460 a
1560 a
1 OT 2 OT
635 b
1560 a
1420 a
1600 a
No PRE Avg. 10 PRE’s
1Study in 1998 conducted at Goldsboro, NC. Studies in 1999 conducted at Goldsboro, NC and Tifton, GA. Data pooled over both locations in 1999.
How Important IsEarly Season Weed Competition?
Can one wait until 4-leaf stage of cotton to initiate weed control?
Depends upon: Weed species
Weed density
Growing conditions
How Important IsEarly Season Weed Competition?
About 33 to 66% of the time we can initiate
weed control at the 3 to 4 leaf stage of cotton.
If in doubt, apply DNA + Cotoran or Staple
The other 33 to 66% of the time we need a soil-
applied herbicide or 2 overtop RU applications.
Weeds Difficult to Control by Glyphosate?
Controlling Yellow and Purple Nutsedge?
Nutsedge Control Programs:
1) 2 applications of glyphosate prior to 5th leaf followed by conventional chemistry including 2 lb ai MSMA directed
2) 1 application of glyphosate or Staple Plus prior to 5th leaf followed by 2 lb ai MSMA directed or glyphosate
3) Zorial or Staple?????
Yellow Nutsedge Control by R’up/MSMA Mixtures. 2 Locs, 1999 -2000.
0
25
50
75
100
1.5 2
No MSMA + MSMA 1.3 pt
Roundup Ultra (pt)
*Control 30 DAT.
7465
8071
% c
ontr
ol
Glyphosate 0.75 lb ae/A + MSMA 1.3 pt
30 days after treatment
Cotton Injury 10 DAT with R’up/MSMA Mixtures. 2 Locs, 1999.
0
10
20
30
40
0 0.5 1 1.5 2
No MSMA + MSMA 1.3 pt
Roundup Ultra (pt)
*Injury by tank mix significantly greater than Roundup applied alone
1216
*
2025 27
% in
jury
* * *
*
Weeds Difficult to Control by Glyphosate?
Mid-Season Morningglory Control by Glyphosate & Glyphosate/Staple Mixtures.
Things to consider?1. Morningglory size at time of application (5+ inches here).2. Will you post-direct with conventional chemistry or glyphosate?
Glyphosate 73 55 89
Glyphosate + Staple 93 76 97
Pitted Smallflower
morningglory morningglory
Loc 1 Loc 2 Loc 1
Roundup Ultra 1.5 pt + Staple 0.6 oz
24 days after treatment - Irrigated, Moultrie, 2000.
18 days after treatment - Irrigated, TyTy, 2001.
Roundup Original 1.5 pt + Staple 0.8 oz
Glyphosate/Staple Tank Mixtures
DuPont new label allows 0.8 oz of Staple to be applied in mixture with glyphosate.
Controlling Extremely Large Morningglory
Weeds Difficult to Control by Glyphosate?
Hemp Sesbania Control by Glyphosate. Tifton, 2000.*
0
20
40
60
80
100
% c
ontr
ol
*Roundup Ultra applied at 2 pt/A. Experiment conducted under center irrigation.
3 inches 7 inches
86
59
Tropical spiderwort, Cairo, GA, 2001. Cooperative work with Tim
Flanders
Fairly common scene at harvest across the state
• present label =– may be applied overtop of 3-12 inch cotton alone– may be directed in mixture with glyphosate in RR
cotton but “do not allow spray solution to contact cotton leaves”
• residual control for Amaranthus, grasses, tropical spiderwort
Dual Magnum + Glyphosate Label
glyphosate @ 4 lf + 1 pt Dual MagnumAttapulgus, 2001
*Irrigated within 48 hrs.
0
20
40
60
80
100
PalmerT. panicumpusleyy. nutsedge
% c
ontr
ol, l
ate-
seas
on
LSD ranged from 9 to 12
TD 1 lf TD 1 lf TD 1 lf
TD 4 lf TD 4 lf TD + Dual Mag. 4 lf
TD timely PD TD 11 d delay TD 11 d delay
Weed Response to Touchdown (TD)/Dual Magnum Systems. Attapulgus, 2001.
• present label =– may be applied overtop of 3-12 inch cotton alone– may be directed in mixture with glyphosate in RR
cotton but “do not allow spray solution to contact cotton leaves”
• residual control for Amaranthus, annual grasses, tropical spiderwort
• any concerns??????
Dual Magnum + Glyphosate Label
Roundup UltraMax
Roundup UltraMax
+
1 pt Dual Magnum
POST
GA Locations Taken to Yield in 2001.
*
***
**
Midville
TiftonTyTy
Moultrie
Attapulgus
No negative effect from Dual plus glyphosate applied overtop of 3- to 4-leaf cotton.
No negative effect noted in 15 locations in NC.
Conventional options:• Caparol + MSMA
• Cobra + MSMA
• Cotoran + MSMA
• Direx + MSMA
• Linex + MSMA (not labeled)
Common Layby Herbicide Options
RR optionslittle to no residual possible residual
glyphosate
glyphosate + Aim
Layby Herbicide Options
• label claims control of:
pigweed species lambsquarters
cocklebur morningglory
velvetleaf spurred anoda
smartweed hemp sesbania
common ragweed
Aim Postemergence-directed
• 0.5 to 1 oz/A (40 DF)
• 1% COC
• Alone or mixed with any registered herbicide
Aim Postemergence-directed
• timing of application:
- cotton at least 6 inches if NO spray contact
- cotton at least 12 inches with minimal contact
Aim Postemergence-directed
Cotton Response to Aim Directed. Cotton 12 to 24 inches.
% cotton injury
Location 1, NC Location 2, NC
DAT DAT
Treatment 5 12 3 11
R’up alone 0 0 0 0
+ 0.6 oz Aim 2 1 12* 4
*Primarily injury to cotton stems; stems not “woody”.
Cotton Response to Aim Directed. Cotton 12 to 24 inches.
% cotton injury
Location 1, GA Location 2, GA
DAT DAT
Treatment 5 14 35 8 23 36
R’up alone 0 0 0 0 0 0
+ 0.6 oz Aim 25 18 0 33 13 2
Primarily injury to cotton stems; stems not “woody”. Yield unaffected.
Most Likely Fit for Aim in Cotton
• Tank mix with glyphosate to improve
morningglory control
Morningglory Control with Roundup + Aim.
% control
Location 1, GA Location 1, NC
Treatment 36 DAT 14 DAT
R’up alone 82 92
+ 0.6 oz Aim 95 100
RR optionslittle to no residual possible residual
glyphosate
glyphosate + Aim
glyphosate + Harvade
Common Layby Herbicide Options
Morningglory Control with Roundup + Harvade.
% control
pitted smallflower
Treatment morningglory morningglory
R’up alone 82 92
+ 8 oz Harvade 95 100
*Add COC in with Harvade.
RR optionslittle to no residual possible residual
glyphosate glyphosate + Caparol
glyphosate + Aim glyphosate + Direx
glyphosate + Harvade
Layby Herbicide Options
Late-season Effect of Direx Applied with Glyphosate in 14” Cotton.
50
60
70
80
90
100
Texas panicum
smallflower morningglory
bristly starbur
Florida pusley
glyphosate
+ 1.5 pt Direx
Glyphosate applied at 1 and 4 leaf cotton. Attapulgus, 2001.
Label requires 20% boll opening in RR cotton
Is there any potential for an earlier application?
Pre-Harvest Glyphosate Applications
8 trials conducted in LA, GA, and NC
glyphosate applied
1. 7 d prior to last effective bloom date
2. on last effective bloom date
3. 7 d after last effective bloom date
4. 14 d after last effective bloom date
5. 20% boll crack
6. no glyphosate
RR Cotton Response to Glyphosate Applied Prior to 20% Boll Opening
7 of 8 trials no negative responses
RR Cotton Response to Glyphosate Applied Prior to 20% Boll Opening
RR Cotton Response to Glyphosate Applied Prior to 20% Boll Opening. Tifton, 2001.
600
800
1000
1200
1400
7BLEBD LEBD 7ALEBD 14ALEBD 20% Crack None
*
*Significantly less than all other treatments.
Lin
t yie
ld/A
Glyphosate
Paraquat
Harvade vs. Aim
Weed Control at Defoliation
Morninglory Leaf and Vine Desiccation. Moultrie, 2001.
0
20
40
60
80
100
Finsh + Harvade +Aim Finish + Harvade + Aim
Per
cent
2 day after treatment
Leaf Vine
Finish applied at 21 oz/A, Aim at 0.66 oz/A, Harvade 10 oz/A.
Morninglory Leaf and Vine Desiccation. Moultrie, 2001.
0
20
40
60
80
100
Finsh + Harvade +Aim Finish + Harvade + Aim
Per
cent
7 day after treatment
Leaf Vine
14 day after treatment
Finish applied at 21 oz/A, Aim at 0.66 oz/A, Harvade 10 oz/A.
Treat bermudagrass and other perennials
Weed Control After Harvest