Keith Jarvi, Tom Hunt, Jerry Echtenkamp

Background information pertaining to corn rootworm larva insecticide experiments conducted at the University of Nebraska Haskell Ag Lab near Concord, NE, 2001.

Species

 

Diabrotica virgifera virgifera LeConte (western corn rootworm)

Diabrotica barberi Smith and Lawrence (northern corn rootworm)

 

Agronomic

 

Hybrid:

Novartis 58D1

Row Spacing:

30 inches

Planting Date:

10 May

Furadan Application:

18 June

Planter:

John Deere Maxemerge, 2 row

Planting Depth:

2 inches

Planting rate:

22,100

               

 

Application Equipment:

 

Granules at planting: Planter mounted cone-belt system, except:

 

 

Aztec 4.67 G and Fortress 5 G applied with Smartbox system

 

Regent liquid formulations: Microtube in-furrow at 1 or 5 gal solution/acre

Capture liquid formulation: 5 inch T band at 5 gal solution/acre

All liquids applied at 24 psi

All seed treatments were pre-treated seed Novartis 58D1

 

Field Preparation

 

One tandem disk October of 2000

 

 

Tandem disked once day of planting

 

Fertilization:

20 Apr: 90 lb N Urea 46-0-0

 

Herbicides:

15 May Axiom (16 oz) + atrazine (1 lb)

Cultivation:

 

18 June after Furadan application

Previous Crop:

 

Corn (trap)

Soil Type:

 

Kennebec silt loam

Organic Matter:

 

3 %

ph

 

6.5

Field History:

 

Late planted mixed variety field corn trap 2000

Irrigation:

 

None

Plot Direction:

 

North-South

 

Experimental Design and Evaluation

 

Randomized complete block with 4 replications

Ratings: Iowa 0-3 scale

Dug and rated 16 and 19 July

 

Comments:   Cold winter but snow provided insulation for eggs.  Untreated check plot had moderately heavy damage.  Slightly above average moisture through the rating dates.  Growing degree-days near average.  See attached sheet for rainfall events.

Keith Jarvi, Tom Hunt, Jerry Echtenkamp.  Corn Rootworm Insecticide Screening Experiment, Haskell Ag Lab, Concord NE 2001.  

 

Application Methods:

TB =  7 inch T-band in front of press wheel at planting time

IF = In-furrow in front of press wheel at planting time

TB Post  = 15” Band over the row on 18 June

MT = Microtube at planting

ST = Seed Treatment

SB  = Smartbox application

 

 

Insecticide Screening Concord, NE 2001  Root Ratings

 

 

Treatment

Application Method

Rate

oz/1000 row ft

Rate

lb ai/1000 row ft

Root

Rating

Aztec 4.67 G SB

TB

3 oz

0.15

0.245

a

 

 

 

 

 

 

Force 3 G

TB

4 oz

0.12

0.250

a

 

 

 

 

 

 

Counter 20 CR

TB

6 oz

1.20

0.278 

a

b

 

 

 

 

 

Aztec 2.1 G BD

TB

6.7 oz

0.14

0.290 

a

b

 

 

 

 

 

Counter 20 CR

IF

6 oz

1.20

0.293 

a

b

 

 

 

 

 

Aztec 2.1 G BD

IF

5.025 oz

0.105

0.298 

a

b

 

 

 

 

 

Fortress 5 G SB

TB

3 oz

0.16

0.323 

a

b

 

 

 

 

 

Lorsban 15 G

TB

8 oz

1.20

0.366 

a

b

 

 

 

 

 

Aztec 2.1 G BD

IF

6.7 oz

0.14

0.375 

a

b

 

 

 

 

 

Fortress 5 G SB

IF

3 oz

0.16

0.388 

a

b

 

 

 

 

 

Regent 4 SC

MT 5 gal

.24 oz

0.13

0.390 

a

b

 

 

 

 

 

Force 3 G

IF

4 oz

0.12

0.418 

a

b

 

 

 

 

 

Force 3 G

IF

3 oz

0.09

0.428

a

b

 

 

 

 

 

Aztec 2.1 G BD

IF

3.35 oz

0.07

0.443

a

b

 

 

 

 

 

Counter 20 CR

IF

3 oz

0.60

0.468

a

b

 

 

 

 

 

Force 3 G

IF

2 oz

0.06

0.480

a

b

 

 

 

 

 

Counter  20 CR

IF

4.5 oz

0.90

0.485

a

b

 

 

 

 

 

Aztec 4.67 G SB

IF

3 oz

0.15

0.493

a

b

 

 

 

 

 

Lorsban 15 G

IF

8 oz

1.20

0.513

a

b

 

 

 

 

 

Regent 4 SC

MT 1 gal

0.24 oz

0.13

0.585

a

b

c

 

 

 

 

Lorsban 15 G

IF

4 oz

0.60

0.620

a

b

c

d

 

 

 

Capture 2 EC

5 in TB 5 gal

0.30 oz

0.0046

0.658

a

b

c

d

 

 

 

Capture 1.15 G

IF

8 oz

0.0054

0.764

a

b

c

d

 

 

 

Lorsban 15 G

IF

6 oz

0.90

0.803

 

b

c

d

e

 

 

Clothianidin 600 FS

ST

1.25 mg/kernel

 

1.090

 

 

c

d

e

 

 

Prescribe 600 FS

ST

1.35 mg/kernel

 

1.115

 

 

c

d

e

 

 

Capture 1.15 G

TB

8 oz

0.0054

1.118

 

 

c

d

e

 

 

ProShield

ST

 

 

1.135

 

 

 

d

e

 

 

Capture 1.15 G

IF

6 oz

0.0040

1.340

 

 

 

 

e

f

 

Furadan 4 F

TB Post

1 qt formulation/acre
broadcast rate

 

1.733

 

 

 

 

 

f

g

Untreated

 

 

 

1.828

 

 

 

 

 

f

g

Untreated

 

 

 

2.205

 

 

 

 

 

 

g

Means with the same letter are not significantly different. (LSD = 0.5438; alpha = 0.05)

 

Keith Jarvi, Tom Hunt, Jerry Echtenkamp.  Corn Rootworm Insecticide Screening Experiment, Haskell Ag Lab, Concord NE 2001.

 

Insecticide Screening Concord, NE 2001

Plant Population per 30 ft of row (10 July)

 

 

Treatment

Application Method

Rate

oz/1000 row ft

Rate

lb ai/1000 row ft

Plant Population

Force 3 G

IF

3 oz

0.09

36.50 a

Capture 2 EC

TB

0.30 oz

0.0046

36.25 a

Regent 4 SC

MT 1 gal

0.24

0.13

36.25 a

Force 3 G

IF

2 oz

0.06

36.25 a

Aztec 2.1 G BD

IF

3.35 oz

0.07

35.75 a

Aztec 2.1 G BD

TB

6.7 oz

0.14

35.50 a

Capture 1.15 G

IF

6 oz

0.0040

35.25 ab

Untreated

 

 

 

35.25 ab

Fortress 5 G SB

TB

3 oz

0.16

35.25 ab

Aztec 4.67 G SB

IF

3 oz

0.15

35.00 abc

Force 3 G

TB

4 oz

0.12

34.50 abc

Aztec 2.1 G BD

IF

6.7 oz

0.14

34.50 abc

Lorsban 15 G

IF

6 oz

0.90

34.25 abc

Lorsban 15 G

IF

4 oz

0.60

34.25 abc

Fortress 5 G SB

IF

3 oz

0.16

34.25 abc

Force 3 G

IF

4 oz

0.12

34.00 abc

Counter 20 CR

IF

3 oz

0.60

34.00 abc

Aztec 2.1 G BD

IF

5.025

0.105

34.00 abc

ProShield

ST

 

 

33.75 abc

Counter 20 CR

TB

6 oz

1.20

33.75 abc

Aztec 4.67 G SB

TB

3 oz

0.15

33.50 abc

Regent 4 SC

MT 5 gal

0.24 oz

0.13

33.25 abc

Lorsban 15 G

IF

8 oz

1.20

33.25 abc

Clothianidin 600 FS

ST

1.25 mg/kernel

 

33.25 abc

Counter 20 CR

IF

4.5 oz

0.90

33.00 abc