MANAGING LARGE MORNINGGLORY
IN ROUNDUP – READY COTTON
WITH LAY-BY HERBICIDES
S.G. Wilson, A.S. Culpepper, and A.C. York
University of Georgia and N. C. State University
STUDY OBJECTIVE:
To Evaluate Lay-By Herbicide Options For
Controlling Large Pitted Morningglories
And Evaluate Plant Injury
Locations
*
Moultrie
*
Ocilla
Materials & Methods
• RR Variety Sprayed at
4-Leaf Stage w/
Commercial Broadcast
Sprayer
• Plots Sprayed At LayBy w/ Backpack
Sprayer @19psi &
14.8 GPA
Materials & Methods
• Randomized Complete
Block Design
• Four Replications
Materials & Methods
• Treatments Evaluated
At ~ Two And Four
Weeks For Efficacy
• Treatments Evaluated
At ~ One And Two
Weeks For Injury
Treatments:
•
•
•
•
•
RU
RU + Direx
RU + Harvade + COC
RU + Staple
RU + Valor
•
•
•
•
•
RU + Aim
RU + MSMA
Caparol + MSMA
Direx + MSMA
Valor + MSMA
*RU abbreviated for various brands of Monsanto’s glyphosate products at
1 lb ai/A, Staple 0.6 to 0.8/A oz, Direx 1.0-1.5 pt/A when mixed with RUand 2
pt/A when mixed with MSMA, Harvade 6-8 oz/A, Aim 0.8-1 oz/A, MSMA 2 lb
ai/A Valor 1 oz/A when mixed with RU and 2 oz/A when mixed with MSMA,
Caparol 2 pt/A, and COC 1 pt/A.
Morningglory Response to Lay-By
Herbicides. 2001.
3-4 ft mg*
TREATMENTS
15 DAT
35 DAT
RU
50 c
55 c
RU + Direx
35 d
55 c
RU + Harvade + COC
53 c
63 bc
RU + Staple
36 d
63 bc
RU + Valor
80 a
74 ab
RU + Aim
65 b
58 c
-
-
Caporal + MSMA
55 bc
59 c
Direx + MSMA
55 bc
59 c
Valor + MSMA
81 a
83 a
RU + MSMA
* Values followed by the same letter within a column are not different at P=0.05
No Directed Application
No Directed Application
No Directed Application
Roundup UltraMax 1.6 pt
No Directed Application
Roundup UltraMax 1.6 pt + Valor 1 oz
No Directed Application
Valor 2 oz + MSMA 2 lb
No Directed Application
Roundup UltraMax 1.6 pt + Harvade 6 oz
Morningglory Re-growth
• Treatments including
Aim looked excellent
initially, but MG’s
suckered back out by
14 DAT (right)
Morningglory Response to Lay-By
Herbicides. 2002.
2 ft mg*
TREATMENTS
16 DAT
36 DAT
RU
59 e
67 f
RU + Direx
47 g
74 c-f
78 bcd
76 def
RU + Staple
95 a
86 a-d
RU + Valor
92 a
91 ab
RU + Aim
94 a
84 a-e
RU + MSMA
80 bc
89 abc
Caporal + MSMA
68 de
81 bc
Direx + MSMA
72 cd
79 c-e
Valor + MSMA
88 ab
95 a
RU + Harvade + COC
* Values followed by the same letter within a column are not different at P=0.05
Large Pitted Morningglory Response
to Lay-By Herbicides. 2003.
9 in mg*
15 DAT
39 DAT
RU
76 c
74 c
RU + Direx
97 a
92 ab
RU + Harvade + COC
91 ab
87 abc
RU + Staple
87 bc
84 bc
RU + Valor
96 ab
94 a
RU + Aim
99 a
92 ab
RU + MSMA
92 ab
92 ab
Caporal + MSMA
91 ab
81 cd
Direx + MSMA
97 ab
84 bc
Valor + MSMA
-
-
TREATMENTS
* Values followed by the same letter within a column are not different at P=0.05
Cotton Response to Lay-By
Herbicides*
‘01 (14” cotton,
green)
5 DAT
14 DAT
‘02 (23” cotton,
bark)
5 DAT
16 DAT
‘03 (15” cotton,
bark)
7 DAT
16 DAT
RU
0d
0d
0d
3d
2c
2d
RU + Direx
0d
0d
6 bc
9a
7b
2d
RU + Harvade + COC
9c
6c
6 bc
4d
10 ab
12 a
RU + Staple
0d
0d
0d
3d
0d
1d
RU + Valor
16 b
12 b
3 cd
3d
12 a
2d
RU + Aim
25 a
18 a
15 a
5 cd
12 a
3 cd
-
-
3 cd
4d
10 ab
8b
Caporal + MSMA
0d
2d
1 cd
6 abc
9 ab
3 cd
Direx + MSMA
3d
3d
9b
8 ab
8b
6 bc
Valor + MSMA
18 b
13 ab
8b
4d
-
-
RU + MSMA
* Values followed by the same letter within a column are not different at P=0.05
Non-treated
Control
Soil Uptake of
Harvade
Herbicide Injury
• Cotton was extremely
green (no woody
material) at time of
application
• At 5 DAT, injury
ranged from 16-25%
for Aim or Valor
Mixtures
Summary
• On 3-4’Mg, RU + Valor or Valor + MSMA
were the most effective treatments
• On 2’ MG, RU + Staple, Valor, or Aim as
well as Valor + MSMA were the most
effective treatments
• On 9” Mg, the most effective treatments
were Direx, Harvade, Valor, Aim or MSMA
when mixed with RU
Summary
• Tank mixes including Aim and Valor were
more injurious
• Injury was worse on green cotton
• Harvade injury appeared as leaf chlorosis
• Injury was short-lived
Summary
• No differences in yield were noted
• Early season weed competition was similar
across the trial
QUESTIONS?
THE END