2002 Cotton
Production Workshop
Tifton, GA
Culpepper and York
Topics for
Discussion
1. Burndown for conservation tillage
2. Liberty Link Technology
3. Roundup Ready Flex
4. Early-season weed competition
5. Touchdown + Dual Magnum
6. CGA 362622 = Envoke; Suprend
7. Aim (directed treatments
8. Valor (directed treatments)
9. Roundup resistance concerns
10. Tropical spiderwort
11. Morningglory
12. Palmer amaranth
13. Glyphosate formulations
Cotton Burndown
Cotton Burndown
Focus: cutleaf eveningprimrose
1. Put 2,4-D out in Feb/March followed by
glyphosate or paraquat near planting
2. Apply glyphosate or paraquat + 2,4-D near
planting (be aware of plant back interval)
Cotton Burndown
1. Put 2,4-D out in Feb/March followed by
glyphosate or paraquat near planting
a) better weed coverage, smaller weeds
b) very flexible at planting
c) no plant back issues
d) tank hopefully cleaned out by now
e) two trips are necessary
Cotton Burndown
2. Apply glyphosate or paraquat + 2,4-D near
planting (be aware of plant back interval)
a) plant back restrictions
b) weed coverage questionable
c) tank cleanout more of an issue
d) single application
If you want use 2,4-D then
Glyphosate plus Clarity*
Or
Glyphosate plus Valor*
*Beware of plant back restrictions
Relative Response of Cutleaf
Eveningprimrose to Glyphosate Tank Mixes.*
2,4-D
13
Clarity
Harmony
Extra
6
Valor
Aim
16
Resource
Alone
0.5
Goal
1
12
7
16
0
6
6
# of trials
*Estimates based on GA and NC data 30 DAT from 1999 to 2002.
Wheat Response to Glyphosate Applied Alone and in
Mixture with Caparol. Ponder Farm, 2001; 16 DAT.
Roundup UltraMax (1.6 pt)
+ 1.5 pt Caparol
Summary - cutleaf eveningprimrose
1. 2,4-D, glyphosate + 2,4-D, paraquat + 2,4-D
2. glyphosate + Valor or Clarity
Percent primrose control by Liberty.
Tifton, 2002. 33 day after treatment.*
100
80
85
93
60
40
56
20
0
20 oz
27 oz
Liberty
*Not an economical option at this time.
32 oz
Wild Radish
Wild Radish Impact on Cotton Emergence
Wild radish
residue*
Cotton stand
reduction
0.5
29
1.0
78
1.5
100
2.0
100
*percent of soil by weight. Jason Norsworthy, Clemson University.
Summary - Wild radish
1. glyphosate + 2,4-D, Harmony Extra
paraquat + 2,4-D, Direx, Harmony Extra
2. glyphosate + Valor, Direx
3. glyphosate
Liberty Link
Cotton
Liberty Link (2003)
1. Approximately 15 bags per sales rep
2. 2 cultivars: 989 and 966 series, no Bt
Liberty Link (2004)
Liberty is expensive…..how will it compete
Liberty Link (2004) – One Possibility
Roundup Ready Seed + 2 application of glyphosate
equals (approximately)
Liberty Link Seed + 2 applications of Liberty (32 oz)
Liberty vs. Roundup*
Weed
Liberty
Roundup
Application window
+
-
Eveningprimrose
+
-
Goosegrass
-
+
Large grasses
-
+
Morningglory
+
-
Nutsedge
-
+
Palmer amaranth
-
+
Perennial grasses
-
+
Volunteer peanut
+
-
*Control of many weeds is similar. Assuming proper rates and application.
Pitted Morningglory Response to Liberty
and Glyphosate. Moultrie, GA, 2001.
non-treated
Liberty
(27 oz/A)
glyphosate
(0.75 lb ae/A)
non-treated
Liberty (27.4 oz/A)
LL cotton trial, TyTy, 2001.
Palmer must be small for Liberty
Possible Liberty Link Systems
1.
Yellow herbicide at plant,
Liberty 1-2 leaf topical,
Liberty 6-8 leaf topical,
timely directed
2.
Yellow plus Cotoran or Staple,
Liberty timely 3- 6 leaf,
timely directed
Roundup Ready Flex
1. Will contain new transformation event
2. Greater gene expression in floral parts
3. Greater tolerance to later overtop applications
4. 2006???
Roundup Ready Flex tolerance study. 2002.
Mechanically harvested seed cotton yield.
lb/A
2500
lb ae/A*
2000
0
1500
1.5
1000
2.25
500
0
Old event**
New event**
*Applied overtop 3-, 6-, 10-, and 14-leaf.
**Not in commercial variety.
Early Season Weed Competition
2 inch weeds
5 inch weeds
Application Timing
8 inch weeds
Early Season Competition
1. First 4 to 6 weeks still most important for weeds
2. Approximately 40% of time use PRE or be
willing to make 2 topical applications
following label recommendations.
Effect of PRE Herbicides on RR Seedcotton Yield.1
Avg. 10 PRE’s
No PRE
1500
1460
a
lb/A
1200
900
600
1070
b
300
0
1 OT
1Study
in 1998 conducted at Goldsboro, NC.
Trifloxysulfuron-sodium
• Trifloxysulfuron-sodium is a postemergence, broad-spectrum, ALS
inhibitor herbicide
• Trifloxysulfuron will be marketed in
two brands:
• Envoke – 75WG trifloxysulfuron
• Suprend – trifloxysulfuron + prometryn
Envoke
1. New product from Syngenta
2. Fourth quarter EPA work plan
3. Broadleaf and sedge herbicide, do NOT
mix with graminicides
4. Short soil residual; limited PRE activity
Envoke vs. Staple*
Weed
Application window
Dayflower species
Morningglory
Nutsedge
Palmer amaranth
Prickly sida
Sicklepod
Smallflower mg**
Tall morningglory
Envoke
Staple
+
++
+
++
+
++
++
++
++
*Assuming proper postemergence rates and application.
**Absolutely no control by Envoke
Zorial PRE
14 DAT
+ Envoke 0.0047 LB A/A
Envoke applied under
favorable conditions
Envoke applied under
14 DAT
dry conditions
Smallflower Morningglory Control. 14 DAT.
glyphosate
Envoke
Envoke
Mix with Staple or glyphosate:
Apparently NO
Envoke
Where might Syngenta promote
the herbicide?
Syngenta RR Cotton Herbicide Program
plus
Nutsedge Control with Envoke
Untreated check
Glyphosate + Dual 1- to 2-leaf
Envoke 5- to 8-leaf
Injury Issues with Envoke
Expect some injury. Usually moderate but
occasionally severe. Recovers quickly with no
yield loss in most studies across Southeast.
Envoke 0.0047 lb/A OT 4-lf
Non-treated Control
Suprend
• New cotton herbicide from Syngenta
• Contains trifloxysulfuron-sodium + prometryn
at 1:133 ratio
• Formulated as 80% WDG
• Applied postemergence-directed
• Use rate of 1 to 1.5 lb/acre
1.0 lb Suprend ~ 1.6 pt Caparol
1.5 lb Suprend ~ 2.4 pt Caparol
• Broadleaf weeds and nutsedge; weak on grasses
Syngenta Cotton Herbicide Program
+ Dual MAGNUM
Touchdown plus Dual Magnum
1. Apply to cotton > 3” but before 5 leaf stage
2. Do not use ANY additive, avoid dew
Injury Range
From glyphosate
plus Dual
Cotton Response to Glyphosate + Dual*
heavy dew
no dew
*Application with dew applied 7 am. Application without dew applied 11 am.
Touchdown plus Dual Magnum
1. Apply to cotton > 3” but before 5 leaf stage
2. Do not use ANY additives, avoid dew
3. Do not mix with staple
Do not apply Dual and Staple within a
couple of days of each other
glyphosate + Dual
glyphosate + Dual + Staple
Touchdown plus Dual Magnum
1. Apply to cotton > 3” but before 5 leaf stage
2. Do not use ANY additives, avoid dew
3. Do not mix with staple
4. Residual weed control of pigweeds,
grasses, pusley, and spiderwort
glyphosate @ 4 leaf cotton
+ Dual Magnum 1 pt/A
1) Dayflower emerged 3 to 7 day after 4 leaf application. Rain 3 d after application.
2) Prowl applied PRE. No layby.
glyphosate @ 4 lf
*Irrigated within 48 hrs.
Attapulgus, 2001
+ 1 pt Dual Magnum
Dual vs. Staple in Glyphosate Topical Mixture*
Weed
Dual
Annual grasses
++
Dayflower species
++
Florida pusley
+
Morningglory
Staple
+
++
Nutsedge
+
Palmer amaranth
++
++
Sicklepod
Cost of treatment
*Assuming proper postemergence rates and application.
++
Do Not Use Dual PRE on Georgia Soils
Dual Magnum PRE
Aim Postemergence-directed
• label claims control of:
pigweed species
lambsquarters
cocklebur
morningglory
velvetleaf
spurred anoda
smartweed
hemp sesbania
common ragweed
Most Likely Fit for Aim in Cotton
Tank mix with glyphosate to improve
morningglory control
Large Morningglory Response to Layby
Herbicides. 5 DAT. Irwin Co., GA, 2001.
Roundup UltraMax 1.6 pt
+ Aim 0.6 oz/A
*Trial conducted on farm in Irwin County with Gibbs Wilson.
Most Likely Fit for Aim in Cotton
What about tank mixing with other products
for morningglory control?
Glyphosate + Aim
Glyphosate alone
directed applications
Plant terminal response to Aim “running” the stem
Aim Application Timing
Treat Aim as a true layby directed herbicide
applying when cotton is at least 16 inches tall
and the stem is completely woody.
Valor for Layby (2004)
•
•
•
•
•
•
4th quarter 2003 EPA workplan
18 inch cotton or larger, completely “woody”
glyphosate plus 1-2 oz per acre
MSMA plus 2 oz per acre
postemergence control of most weeds
residual control of many weeds
Large Morningglory Response to Layby
Herbicides. 5 DAT. Irwin Co., GA, 2001.
Roundup UltraMax 1.6 pt
UltraMax 1.6 pt + Valor 1 oz
*Trial conducted on farm in Irwin County with Gibbs Wilson.
Valor for Layby (2004)
• Off-labeled use of this product in
2003 could jeopardize the potential
for a 2004 label
Weed Resistance
to Glyphosate
Weed Resistance to Glyphosate:
Should We Be Concerned?
Weed Resistance to Glyphosate:
Should We Be Concerned?
ABSOLUTELY!
Known Cases of Resistance to Glyphosate
Species
Location
Goosegrass
Malaysia
Rigid ryegrass
California, Australia,
South Africa
Italian ryegrass
Horseweed
Chile
Tennessee, Delaware
HORSEWEED
How Can We Deal With Resistance?
1. Take your chances, deal with it
if and when it happens
2. Manage to avoid it, or at least delay
its development
Practical Things to Help Avoid Resistance
1. Avoid over-reliance on same mode of action
a. Rotate modes of action
b. Use more than one MOA
Tank mixes, sequential applications
Practical Things to Help Avoid Resistance
1. Avoid over-reliance on same mode of action
a. Rotate modes of action
MOA tables in Extension pubs or online
b. Use more than one MOA
Tank mixes, sequential applications
2. Integrate non-chemical control, such as
cultivation and primary tillage, where practical
Detecting Herbicide Resistance
• Most control failures NOT due to resistance
• Eliminate other possible causes first
– Inadequate herbicide rate
– Poor/improper application
– Poor timing of application
– Unfavorable weather
–
Later weed flushes
– Antagonism by other pesticides
Indicators of Resistance
• Performance poor on one species, other
species controlled well
• Product normally controls weed in question
• Poor control confined to spots in field
• Some plants of species in question controlled
well, others controlled poorly
Progression of
Year 1
Herbicide Resistance
Year 3
Year 2
Year 4
Year 5
Weed Shifts are a
greater issue at this
time in Georgia cotton
Tropical
spiderwort
Asiatic dayflower
Spreading dayflower
below
ground
fruiting
structures
above ground
seed
below ground
seed
Spiderworts rank as Georgia’s
Most troublesome weeds in cotton
1999: not ranked
2001: ninth
2003: number 1
Spiderwort response to Roundup UltraMax*
20 oz
0 oz
30 oz
40 oz
0 oz
50 oz
0 oz
0 oz
*Pictures 15 d after treatment. No plants died from any treatment.
37 “systems” evaluated at 2 locations
to control tropical spiderwort in 2002.
Control at harvest:
< 50% control: 49
50 to 80% control: 19
80-90% control: 5
>90% control: 1
Grady Co. 2002
What do we know from 2002?
Greater than 85% residual control at 30 days:
Command
Dual (can not use at plant)
Greater than 70% residual control at 30 days:
Cotoran
Direx*
Zorial
*Caparol or Cotton-Pro not included in trial.
What do we know from 2002?
Postemergence control (<3 inch):
1. Paraquat (Gramoxone, Boa) (>90%)
2. MSMA (2 lb/A) tank mixes (80-90%)
3. Glyphosate + Aim, Direx, Staple (70-85%)
What do we know from 2001-2002?
Best system so far:
Prowl/Treflan at plant (no effect on spiderwort)
Glyphosate + Dual early POST
Direx (1 qt) + MSMA (2 lb/A) directed
All applications were EXTREMELY timely.
Percent tropical spiderwort control at cotton
harvest. Grady County, 2001-2002.
100
95
80
87
78
60
40
57
2001
2001
2002
2002
20
0
Yellow herbicide at plant; glyphosate + Dual early Post; Direx + MSMA directed
What do we know from 2002?
1) We must get more residual in the program
2) Where do we put the residual
3) We must learn spiderwort emergence
pattern
4) If you don’t have the weed; make sure you
don’t get it.
Tropical Spiderwort Infestation
Red = severe
Orange = moderate
Green = light
Yellow = exist
Gray = not found
Morningglory Continues to be
Troublesome to Georgia Growers?
WHY??????
Morningglory Continues to be
Troublesome to Georgia Growers?
At plant:
Cotoran, Direx, Staple
Early Post:
Glyphosate, Staple, Staple Plus
Directed:
MSMA plus Caparol, Cobra, Cotoran, Direx, Staple,
glyphosate plus Aim, Caparol, Direx, Harvade, Staple
Morningglory Continues to be
Troublesome to Georgia Growers?
1) Timeliness of application
(i.e. large at time of application)
2) No residual in the system
Residual Morningglory Control?
•
•
•
•
Cotoran
Direx
Staple
Caparol
Fairly common scene at harvest across the state
Two Possible Issues?
1. Pigweed is to large at time of layby
2. Pigweed comes up after layby
Two Possible Issues?
1. Pigweed is to large at time of layby
a) add a preemergence herbicide such a
yellow herbicide, Cotoran, Staple
b) Add Dual or Staple in at early POST
Two Possible Issues?
2. Pigweed comes up after layby
a) use layby option with residual activity
such as Direx, Caparol, Prowl
Glyphosate
Formulations
Glyphosate Formulations
• Numerous brands available
• All registered for burndown,
selective applicators, and
preharvest
• Most, but not all, registered
for use in RR crops
Registered Uses on Roundup Ready Crops
Brand
Soybean
Corn
Cotton
Clearout 41 Plus
Yes
Yes
Yes
Gly-4
Yes
Yes
Yes
Gly-4 Plus
Yes
Yes
Yes
Gly-Flo
No
Yes
No
Glyfos
Yes
Yes
Yes
Glyfos X-TRA
Yes
Yes
Yes
Glyphomax
Yes
Yes
Yes
Glyphomax Plus
Yes
Yes
Yes
Gly Star Original
Yes
Yes
Yes
Gly Star Plus
Yes
Yes
Yes
Roundup Original
Yes
Yes
No
Roundup UltraMax
Yes
Yes
Yes
Roundup WeatherMax
Yes
Yes
Yes
Touchdown
Yes
Yes
Yes
Glyphosate Formulations
• Numerous brands available
• Three basic formulations
=
=
O
O
=
O
=
O
O
O
CH3
HO-C-CH2-N-CH2-P-OH2N-CH
O
O
=
Glyphosate diammonium salt
=
Glyphosate acid
=
H3NO-C-CH2-N-CH2-P-ONH3
=
HO-C-CH2-N-CH2-P-OH
HO-C-CH2-N-CH2-P-OK
CH3
Glyphosate isopropylamne salt
Glyphosate potassium salt
Glyphosate Formulations
• Some brands are “loaded”, some
require surfactant; AMS and drift
control agent can be added to any
• Formulations and concentrations vary;
only way to compare use rates is on
the basis of acid equivalence
Basic Glyphosate Formulations
Formulation
Brand
lb salt/gal
lb ae/gal
diammonium
Touchdown
3.57
3.0
Roundup
5.5
4.5
All except
4.0
3.0
the above
5.0
3.7
5.4
4.0
salt
potassium
salt
isopropylamine
salt
WeatherMax
Formulation
lb salt/gal
lb ae/gal
Comparative rates
IPA salt
4.0
3.0
0.375 lb ae = 16 fl oz
0.563 lb ae = 24 fl oz
0.750 lb ae = 32 fl oz
IPA salt
5.0
3.7
0.375 lb ae = 13.0 fl oz
0.563 lb ae = 19.5 fl oz
0.750 lb ae = 26.0 fl oz
DA salt
3.57
3.0
0.375 lb ae = 16 fl oz
0.563 lb ae = 24 fl oz
0.750 lb ae = 32 fl oz
K salt
5.5
4.5
0.375 lb ae = 10.7 fl oz
0.563 lb ae = 16.0 fl oz
0.750 lb ae = 21.3 fl oz
So, which brand of glyphosate
should you use?
So, which brand of glyphosate
should you use?
1.
Crop and weeds apparently don’t care
So, which brand of glyphosate
should you use?
1.
Crop and weeds apparently don’t care
2.
Pricing is important
So, which brand of glyphosate
should you use?
1.
Crop and weeds apparently don’t care
2.
Pricing is important
3.
Also consider service and guarantees
So, which brand of glyphosate
should you use?
1.
Crop and weeds apparently don’t care
2.
Pricing is important
3.
Also consider service and guarantees
4.
Should you consider future
developments in technology?
Roundup WeatherMax
1.
Replacing UltraMax
2.
Potassium salt
5.5 lb salt/gal; 4.5 lb ae/gal
3.
30-min rainfree warranty
4.
Claim better activity under marginal
conditions
5.
Better bulk handling characteristics
2002 Cotton
Production Workshop
Tifton, GA
Culpepper and York