|
|
| |
|
Efficacy
of Registered and Experimental Insecticides
to Control Corn Rootworm Larvae at Three
Locations in Illinois, 2000 |
| |
|
John
T. Shaw, Michael E. Gray, and Kevin
L. Steffey |
|
| Summary
|
|
Three
experiments were conducted to determine
the efficacy of registered and experimental
soil insecticides for control of corn
rootworm larvae at DeKalb, Monmouth,
and Urbana in 2000. Average root injury
ratings in untreated control plots at
these locations were 4.18, 4.14, and
5.03, respectively. Although the registered
soil insecticides [Aztec 2.1G (band),
Counter 20CR (band), Force 3G (band
and furrow), Fortress 5G (furrow), Lorsban
15G (band)], provided adequate root
protection at each of the locations,
the seed treatments ProShield and Gaucho
(0.6, 1.0 and 1.3 mg per seed rates)
did not keep root injury below the economic
injury index of 3.0. Consistency ratings
of the seed treatments revealed the
very erratic root protection afforded
by these products. Root injury was maintained
at satisfactory levels in plots treated
with Capture 2EC at Monmouth and Urbana.
The root protection provided by Capture
2EC was more erratic in DeKalb. The
band application of Regent 4SC kept
root injury below the economic injury
index at each of the three test locations.
Microtube applications of Regent 4SC
provided less consistent root protection
in DeKalb and Monmouth while the opposite
was true in Urbana. Furadan 4F was applied
only at the Urbana site and failed to
provide adequate root protection (average
root rating of 3.80). |
|
| Plot
Information and Methods |
|
Locations
Corn rootworm insecticide trials were
established at the following locations:
1. Northern Illinois Agronomy Research
Center, DeKalb, Illinois
2.Northwestern Illinois Agricultural
Research and Demonstration Center, Monmouth,
Illinois
3. University of Illinois, Crop Sciences
Research & Education Center, Field
EG-200 NE, Urbana, Illinois.
Plot Size
Each insecticide was applied to one
row (40 feet long). Alleys (20 feet
wide) were established between all replications
at each location.
Experimental
Design
A randomized complete block with four
replications was utilized as the experimental
design at all locations. Two untreated
control plots were included within each
replication. Data collected from the
untreated control plots were averaged
for the analysis of variance (ANOVA).
Planting Dates and Agronomic
Factors
See Table 4.1.
Pre-Treatment
Population
The Monmouth and DeKalb locations were
planted (1999) as trap crops (late-planted
corn and pumpkins) in an effort to enhance
rootworm oviposition and increase larval
densities in 2000. At the Urbana location
a late-planted cornfield was sprayed
with a mixture of buffalo gourd root
powder and water to increase the level
of larval injury in 2000.
Method of Application for Granules
at Planting Time
Granular insecticides were applied at
planting and metered through computer
controlled SmartBox (SBX) granular applicators
or Noble® units mounted
on each row of an ALMACO®
four-row precision planter. Insecticides
were applied in-furrow or in a 7-in.
band ahead of the firming wheels on
the planter. Spring tines mounted behind
each planter unit were used to incorporate
the insecticide. All rates are specified
as lb. (AI)/acre based on a 30-inch
row spacing.
Method of
Application for Liquids at Planting
time
Regent 4SC, Force WF2829 30CS and Force
WF 2899 25CS were delivered in-furrow
at planting through microtubes calibrated
to deliver 2.1 gpa at 30 psi at a speed
of 3.0 mph at all three locations.
Capture 2EC, Force WF2829 30CS, Warrior
T 1SC and Force WF2899 25CS were applied
through a single 8003 (flat fan) nozzle
in-furrow or as a band and calibrated
to deliver 4.9 gpa at 21 psi at a speed
of 3.0 mph.
Method of Application
for Liquids at Rootworm Egg Hatch
At the Urbana location only Furadan
4F insecticide treatment was applied
on May 26, with a CO2 backpack
sprayer with two 8002VS nozzles directed
on either side of a single row and calibrated
to deliver 20.4 gpa at 20 psi.
Seed Treatments
All seed treatments were applied to
NK 58D-1 seed by the respective company.
This same seed variety was utilized
for all treatments in all three locations.
Stand Counts
Stand count data (Table 4.2) were determined
by recording the number of plants per
0.001 acre (17.4 linear feet of row).
Phytotoxicity
Symptoms of phytotoxicity were not observed
at the three locations for any of the
insecticide treatments.
Other
Observations
No major handling or calibration problems
occurred with any of the insecticides.
Post-Treatment Evaluation of
Rootworm Injury
Five plants per treatment per replication
were dug, washed, and evaluated for
rootworm injury. The root-rating system
used was the Iowa State University root-rating
scale described by Hills and Peters
(1971):
- No visible damage or only a few
minor feeding scars
- Some roots with feeding scars
but none eaten off to within 1.5
inches of the plant
- Several roots eaten off to within
1.5 inches of the plant but never
the equivalent of an entire node
of roots destroyed
- One node of roots destroyed or
the equivalent
- Two nodes of roots destroyed or
the equivalent
- Three or more nodes of roots destroyed.
Root rating data are presented in Table
4.3. Consistency ratings also are provided
in Table 4.4 and are based upon the
percentage of the total number of roots
examined for each treatment that had
root ratings less than 4.0.
Weather Information
See Appendix A, Tables
A.1 and A.2,
A.4
and A.5,
A.6
and A.7,
for Urbana, DeKalb, and Monmouth, respectively.
Statistical Analysis
Data were analyzed with the Agriculture
Research Manager (ARM) version 6.1.6,
from Gylling Data Management, Inc.(GDM).
Means were separated by Duncan’s
New MRT test (P=0.05). |
|
| Results
and Discussion |
|
Stand
counts were taken at DeKalb and Urbana
(Table 4.2). The number of plants per
0.001 acre (17.4 linear feet of row)
was not statistically different among
the treatments in DeKalb. At the Urbana
location, significantly fewer plants
were observed in plots treated with
the seed treatment (EX-5) and Fortress
5G (0.19 lb. AI/acre) applied in-furrow.
Average root injury ratings in untreated
control plots at DeKalb, Monmouth, and
Urbana were 4.18, 4.14, and 5.03, respectively.
This level of root injury in control
plots represents moderate pressure (a
single node of roots destroyed) for
DeKalb and Monmouth. Larval injury at
Urbana was severe (two nodes of roots
destroyed) in the control plots. Although
the registered soil insecticides [Aztec
2.1G (band), Counter 20CR (band), Force
3G (band and furrow), Fortress 5G (furrow),
Lorsban 15G (band)], provided adequate
root protection at each of the locations,
the seed treatments ProShield and Gaucho
(0.6, 1.0 and 1.3 mg per seed rates)
did not keep root injury below the economic
injury index of 3.0. Consistency ratings
of the seed treatments revealed the
very erratic root protection afforded
by these products.
Several soil insecticides were applied
as liquid formulations and included
Capture 2EC, Furadan 4F, and Regent
4SC. Root injury in plots treated with
Capture 2EC was kept below the economic
injury index (3.0) at Monmouth and Urbana.
However, root injury at DeKalb exceeded
this level (3.65) in plots treated with
Capture 2EC at the 0.09 lb. (AI)/acre
rate. Curiously, when Capture 2EC was
applied at a lower rate (0.08 lb. (AI)/acre),
roots averaged 2.85 in these plots.
Consistency ratings (Table 4.4) for
this product, particularly at DeKalb,
suggests more data are required before
we can fully assess the long-term reliability
of this product. Root injury ratings
were kept below the economic injury
index in plots treated with Regent 4SC
as a band application. More root injury
occurred in plots treated with microtube
applications of Regent 4SC in DeKalb
and Monmouth, 3.0 and 3.25, respectively.
At Urbana, microtube applications of
Regent 4SC provided very good root protection.
Furadan 4F was applied only at the Urbana
site and failed to provide adequate
root protection (average root rating
of 3.80). Consistency data revealed
that 67% of the roots in plots treated
with Furadan 4F exceeded a root injury
rating of 4.0.
Reference
Cited
Hills, T.M., and D.C. Peters. 1971.
A method of evaluating post-plant insecticide
treatments for control of western corn
rootworm larvae. J. Econ Entomol. 64:764-765.
|
|
| Table
4.1. |
|
Agronomic
factors and evaluation dates at three
locations to test corn rootworm soil
insecticides, Illinois, 2000 |
| |
|
| Variables
|
DeKalb |
Monmouth |
Urbana |
Planting date
|
May 17, 2000 |
May 16, 2000 |
April 28, 2000
|
Hybrid
|
NK58 D-1 |
NK58 D-1 |
NK58 D-1 |
| Plant population
|
28,500 seeds per
acre |
28,500 seeds per
acre |
28,500 seeds per
acre |
| Row spacing |
30 inches |
30 inches |
30 inches |
| Soil condition
(top 2-3 inches) |
Moist |
Moist |
Dry |
| Soil temperature
(4-inch level) |
60oF
|
63oF
|
61oF
|
| Air temperature
|
70oF
|
70oF
|
65oF
|
| Wind |
8 — 10 mph
|
5 — 7 mph
|
2 — 4 mph
|
Previous crop
|
trap crop —
corn + pumpkins (1999) |
trap crop —
corn + pumpkins (1999) |
trap crop —
corn (1999) |
| Soil insecticides
|
None |
None |
None |
| Herbicides |
Degree (pre-emergence)
Balance, Aatrex (post-emergence)
|
Degree, Atrazine
(pre-emergence) Basagran, UAN
(post-emergence) |
|
| Fertilizer |
Anhybrous 180
lbs. |
N 160 lb/Acre
|
|
| Fall tillage |
Coulter Chisel
|
Chisel plow |
|
| Spring tillage
|
Mulch finisher
twice |
Dyna-drive |
|
| Cultivation date
|
June 8 |
None |
|
| Evaluation dates
|
|
|
|
| Stand counts |
June 1 |
---- |
June 5 |
| Root ratings |
July 25 |
July 24 |
July 13 |
|
|
| Table
4.2 |
|
Mean
stand counts for corn rootworm soil
insecticides at two locations, Illinois,
2000 |
| |
|
|
Treatment |
Rate1
|
Placement |
Stand Counts2
|
|
DeKalb |
Urbana |
| Capture 2EC |
0.090
|
band |
23.75
|
abc |
27.00
|
a-d |
| Capture 2EC |
0.080
|
band |
27.75
|
ab |
25.75
|
a-d |
| Furadan 4F |
1.000
|
broadcast |
24.50
|
abc |
25.25
|
a-d |
| Aztec 2.1G |
0.150
|
band |
21.75
|
bc |
24.50
|
a-d |
| Aztec BD 2.1G
|
0.150
|
band |
26.00
|
ab |
25.00
|
a-d |
| Aztec BD 2.1G
|
0.110
|
band |
26.00
|
ab |
25.75
|
a-d |
| Force 3G |
0.130
|
furrow |
24.75
|
abc |
23.25
|
a-d |
| Force 3G |
0.130
|
band |
22.50
|
bc |
29.00
|
a |
| EX-4 |
|
seed treatment
|
29.00
|
a |
24.75
|
a-d |
| EX-5 |
|
seed treatment
|
26.25
|
ab |
21.50
|
d |
| EX-6 |
|
seed treatment
|
24.75
|
abc |
22.25
|
bcd |
| Force WF2829 30CS
|
0.080
|
band |
25.00
|
ab |
26.75
|
a-d |
| Force WF2829 30CS
|
0.120
|
band |
25.00
|
ab |
26.25
|
a-d |
Force WF2829 30CS
Force WF2829 30CS |
0.160
0.080 |
band
microtube |
22.00
|
bc |
27.75
|
a-d |
| 23.00
|
abc |
27.50
|
a-d |
| Force WF2829 30CS
|
0.120
|
microtube |
21.75
|
bc |
25.75
|
a-d |
| Force WF2829 30CS
|
0.160
|
microtube |
25.75
|
ab |
26.75
|
a-d |
| Regent 4SC |
0.130
|
microtube |
23.33
|
abc |
23.50
|
a-d |
| Regent 4SC |
0.130
|
band |
23.50
|
abc |
26.50
|
a-d |
| Lorsban 15G |
1.300
|
band |
24.75
|
abc |
26.00
|
a-d |
| Lorsban 15G |
1.300
|
furrow |
23.00
|
abc |
22.75
|
a-d |
| ProShield |
|
seed treatment
|
26.00
|
ab |
25.75
|
a-d |
| Pilot 15G |
1.300
|
band |
23.00
|
abc |
25.00
|
a-d |
| CRAG-00011 20G
|
1.000
|
band |
26.25
|
ab |
26.50
|
a-d |
| CRAG-00011 20G
|
0.750
|
band |
23.00
|
abc |
26.50
|
a-d |
| CRAG-00011 20G
|
0.500
|
band |
23.67
|
abc |
25.50
|
a-d |
| NuFos 15G |
1.300
|
band |
26.50
|
ab |
24.75
|
a-d |
| Counter 20CR |
1.300
|
band |
23.75
|
abc |
24.25
|
a-d |
| Warrior T 1CS
|
0.030
|
band |
26.50
|
ab |
23.50
|
a-d |
| Warrior T 1CS
|
0.060
|
band |
25.50
|
ab |
28.25
|
abc |
| Warrior T 1CS
|
0.090
|
band |
24.75
|
abc |
23.75
|
a-d |
| Force WF2899 25CS
|
0.125
|
band |
24.75
|
abc |
22.25
|
bcd |
| Force WF2899 25CS
|
0.125
|
microtube |
21.75
|
bc |
29.25
|
a |
| Fortress 5G |
0.160
|
band |
22.25
|
bc |
25.25
|
a-d |
| Fortress 5G |
0.160
|
furrow |
26.50
|
ab |
26.50
|
a-d |
| Gaucho |
1.300
|
seed treatment
|
23.50
|
abc |
23.75
|
a-d |
| Gaucho |
1.000
|
seed treatment
|
22.00
|
bc |
24.75
|
a-d |
| Gaucho |
0.600
|
seed treatment
|
25.00
|
ab |
26.50
|
a-d |
| Fortress 5G |
0.190
|
furrow |
25.33
|
ab |
22.00
|
cd |
| Fortress 5G |
0.220
|
furrow |
18.75
|
c |
23.75
|
a-d |
| Control |
|
|
23.50 |
abc |
28.75 |
ab |
|
| |
|
1Rates
are specified as lb (AI)/acre, except
for seed treatments which are expressed
as mg/seed.
2Means in a column followed
by the same letter are not significantly
different (P=0.05; Duncan’s New
MRT). |
|
| Table
4.3. |
|
Mean
root ratings for corn rootworm soil
insecticides at three locations, Illinois,
2000 |
| |
|
|
Treatment |
Rate1
|
Placement |
Root Ratings2
|
|
DeKalb |
Monmouth |
Urbana |
| Capture 2EC |
0.090
|
band |
3.65
|
a-f |
2.25
|
e-h |
2.60
|
f-l |
| Capture 2EC |
0.080
|
band |
2.85
|
d-m |
2.50
|
efg |
2.85
|
d-l |
| Furadan 4F |
1.000
|
broadcast |
---
|
---
|
3.80
|
bcd |
| Aztec 2.1G |
0.150
|
band |
1.85
|
m |
1.60
|
gh |
2.60
|
f-l |
| Aztec BD 2.1G
|
0.150
|
band |
1.95
|
lm |
1.65
|
gh |
2.00
|
l |
| Aztec BD 2.1G
|
0.110
|
band |
2.05
|
klm |
1.75
|
gh |
2.89
|
d-l |
| Force 3G |
0.130
|
furrow |
2.20
|
j-m |
1.67
|
gh |
2.30
|
i-l |
| Force 3G |
0.130
|
band |
1.85
|
m |
2.80
|
d-g |
2.05
|
kl |
| EX-4 |
|
seed treatment
|
3.47
|
a-h |
4.25
|
a |
3.20
|
b-j |
| EX-5 |
|
seed treatment
|
3.49
|
a-h |
2.20
|
e-h |
2.90
|
d-l |
| EX-6 |
|
seed treatment
|
3.70
|
a-e |
2.60
|
d-g |
2.95
|
d-l |
| Force WF2829 30CS
|
0.080
|
band |
2.45
|
h-m |
2.35
|
e-h |
2.73
|
e-l |
| Force WF2829 30CS
|
0.120
|
band |
2.10
|
klm |
2.05
|
e-h |
2.28
|
i-l |
| Force WF2829 30CS
|
0.160
|
band |
2.06
|
klm |
3.25
|
a-e |
2.53
|
g-l |
| Force WF2829 30CS
|
0.080
|
microtube |
2.95
|
c-l |
3.00
|
c-f |
2.45
|
h-l |
| Force WF2829 30CS
|
0.120
|
microtube |
2.60
|
f-m |
2.60
|
d-g |
3.05
|
c-l |
| Force WF2829 30CS
|
0.160
|
microtube |
2.73
|
e-m |
2.41
|
e-h |
2.45
|
h-l |
| Regent 4SC |
0.130
|
microtube |
3.00
|
c-l |
3.25
|
a-e |
2.45
|
h-l |
| Regent 4SC |
0.130
|
band |
2.55
|
g-m |
2.60
|
d-g |
2.80
|
d-l |
| Lorsban 15G |
1.300
|
band |
2.50
|
g-m |
2.65
|
d-g |
2.13
|
kl |
| Lorsban 15G |
1.300
|
furrow |
3.57
|
a-g |
1.95
|
fgh |
2.20
|
jkl |
| ProShield |
|
seed treatment
|
4.35
|
a |
3.75
|
a-d |
3.55
|
b-g |
| Pilot 15G |
1.300
|
band |
2.70
|
e-m |
2.20
|
e-h |
2.05
|
kl |
| CRAG-00011 20G
|
1.000
|
band |
3.25
|
b-j |
2.10
|
e-h |
2.35
|
i-l |
| CRAG-00011 20G
|
0.750
|
band |
2.60
|
f-m |
2.20
|
e-h |
2.63
|
e-l |
| CRAG-00011 20G
|
0.500
|
band |
2.53
|
g-m |
3.10
|
a-f |
3.41
|
b-h |
| NuFos 15G |
1.300
|
band |
2.25
|
i-m |
2.20
|
e-h |
3.25
|
b-i |
| Counter 20CR |
1.300
|
band |
2.67
|
e-m |
1.20
|
h |
2.14
|
kl |
| Warrior T 1CS
|
0.030
|
band |
3.85
|
a-d |
2.55
|
d-g |
3.45
|
b-h |
| Warrior T 1CS
|
0.060
|
band |
3.30
|
b-i |
4.20
|
ab |
3.06
|
c-k |
| Warrior T 1CS
|
0.090
|
band |
3.90
|
a-d |
3.05
|
b-f |
2.71
|
e-l |
| Force WF2899 25CS
|
0.125
|
band |
2.15
|
klm |
2.40
|
e-h |
3.00
|
c-l |
| Force WF2899 25CS
|
0.125
|
microtube |
2.70
|
e-m |
2.10
|
e-h |
2.60
|
f-l |
| Fortress 5G |
0.160
|
band |
3.05
|
c-k |
---
|
4.09
|
b |
| Fortress 5G |
0.160
|
furrow |
3.25
|
b-j |
2.15
|
e-h |
2.10
|
kl |
| Gaucho |
1.300
|
seed treatment
|
3.90
|
a-d |
3.20
|
a-f |
3.65
|
b-e |
| Gaucho |
1.000
|
seed treatment
|
3.95
|
abc |
3.00
|
c-f |
3.60
|
b-f |
| Gaucho |
0.600
|
seed treatment
|
4.35
|
a |
3.25
|
a-e |
4.00
|
bc |
| Fortress 5G |
0.190
|
furrow |
2.80
|
e-m |
2.15
|
e-h |
2.50
|
h-l |
| Fortress 5G |
0.220
|
furrow |
2.35
|
i-m |
2.65
|
d-g |
2.20
|
jkl |
|
Control |
|
|
4.18 |
ab |
4.14 |
abc |
5.03 |
a |
|
| |
|
1Rates
are specified as lb (AI)/acre, except
for seed treatments which are expressed
as mg/seed.
2Means in a column followed
by the same letter are not significantly
different (P=0.05; Duncan’s New
MRT). |
|
| Table
4.4. |
|
Mean
consistency ratings for corn rootworm
soil insecticides at three locations,
Illinois, 2000 |
| |
|
|
Treatment |
Rate1
|
Placement |
Consistency
Ratings2,3 |
|
DeKalb |
Monmouth |
Urbana |
| Capture 2EC |
0.090
|
band |
40
|
90
|
80
|
| Capture 2EC |
0.080
|
band |
80
|
90
|
80
|
| Furadan 4F |
1.000
|
broadcast |
---
|
---
|
33
|
| Aztec 2.1G |
0.150
|
band |
100
|
100
|
100
|
| Aztec BD 2.1G
|
0.150
|
band |
100
|
100
|
100
|
| Aztec BD 2.1G
|
0.110
|
band |
100
|
100
|
79
|
| Force 3G |
0.130
|
furrow |
95
|
100
|
95
|
| Force 3G |
0.130
|
band |
100
|
80
|
100
|
| EX-4 |
|
seed treatment
|
60
|
65
|
65
|
| EX-5 |
|
seed treatment
|
58
|
95
|
80
|
| EX-6 |
|
seed treatment
|
30
|
90
|
75
|
| Force WF2829 30CS
|
0.080
|
band |
80
|
85
|
87
|
| Force WF2829 30CS
|
0.120
|
band |
95
|
95
|
100
|
| Force WF2829 30CS
|
0.160
|
band |
100
|
65
|
93
|
| Force WF2829 30CS
|
0.080
|
microtube |
70
|
65
|
90
|
| Force WF2829 30CS
|
0.120
|
microtube |
85
|
80
|
75
|
| Force WF2829 30CS
|
0.160
|
microtube |
80
|
79
|
100
|
| Regent 4SC |
0.130
|
microtube |
80
|
65
|
100
|
| Regent 4SC |
0.130
|
band |
100
|
75
|
67
|
| Lorsban 15G |
1.300
|
band |
90
|
80
|
100
|
| Lorsban 15G |
1.300
|
furrow |
57
|
100
|
100
|
| ProShield |
|
seed treatment
|
20
|
35
|
50
|
| Pilot 15G |
1.300
|
band |
90
|
95
|
100
|
| CRAG-00011 20G
|
1.000
|
band |
55
|
100
|
95
|
| CRAG-00011 20G
|
0.750
|
band |
85
|
100
|
95
|
| CRAG-00011 20G
|
0.500
|
band |
93
|
70
|
59
|
| NuFos 15G |
1.300
|
band |
90
|
100
|
45
|
| Counter 20CR |
1.300
|
band |
73
|
100
|
95
|
| Warrior T 1CS
|
0.030
|
band |
35
|
85
|
65
|
| Warrior T 1CS
|
0.060
|
band |
50
|
25
|
58
|
| Warrior T 1CS
|
0.090
|
band |
40
|
70
|
89
|
| Force WF2899 25CS
|
0.125
|
band |
100
|
85
|
75
|
| Force WF2899 25CS
|
0.125
|
microtube |
70
|
100
|
90
|
| Fortress 5G |
0.160
|
band |
60
|
---
|
26
|
| Fortress 5G |
0.160
|
furrow |
55
|
100
|
100
|
| Gaucho |
1.300
|
seed treatment
|
35
|
50
|
40
|
| Gaucho |
1.000
|
seed treatment
|
25
|
65
|
50
|
| Gaucho |
0.600
|
seed treatment
|
25
|
60
|
32
|
| Fortress 5G |
0.190
|
furrow |
87
|
100
|
95
|
| Fortress 5G |
0.220
|
furrow |
95
|
80
|
100
|
| Control |
|
|
30 |
30 |
0 |
|
| |
|
1Rates
are specified as lb (AI)/acre, except
for seed treatments which are expressed
as mg/seed.
2Means in a column
followed by the same letter are not
significantly different (P=0.05; Duncan’s
New MRT).
3Consistency rating is
the percentage of the total number
of roots examined with a root rating
less than 4.0 |
| |
|
|
