2002 Nebraska Insecticide Evaluations

Researchers: Keith Jarvi, Tom Hunt, Jerry Echtenkamp

Location: University of Nebraska Haskell Agricultural Laboratory near Concord, Nebraska

Evaluation: Corn Rootworm larva insecticide

Species: Diabrotica virgifera virgifera LeConte (western corn rootworm)

Diabrotica barberi Smith and Lawrence (northern corn rootworm)

Hybrid	Novartis 58D1
Row Spacing	30 inches
Planting Date	15 May
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, Fortress 3.5 G and Fortress 5 G applied with Smartbox system Regent liquid formulation: Microtube in-furrow at 5 gal solution/acre Leverage and Capture liquid formulations: 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 29 October of 2001. Tandem disked once day of planting
Fertilization	10 Apr: 100 lb N Urea 46-0-0
Herbicides	16 May Axiom (16 oz) + atrazine (1 lb)
Cultivation	28 June
Previous Crop	Corn (trap)
Soil Type	Kennebec silt loam
Organic Matter	3 %
ph	6.5
Field History	Late planted mixed variety field corn trap 2001
Irrigation	None
Plot Direction	North-South

Experimental Design and Evaluation

Randomized complete block with 4 replications

Ratings: Iowa 0-3 scale

Dug and rated 15 and 16 July

Comments: Mild winter with no snow cover. Untreated check plot had lower damage than normal probably due to very dry conditions pre and post plant, which may have hurt larval establishment. Below average moisture occurred through the rating dates. Growing degree-days near average. See attached sheet for rainfall events.

No significant differences occurred between treatments. However, two of the three untreated plots had significantly higher damage than the insecticide treatments. In this situation all the treatments end up looking ok. No phytotoxic symptoms were observed on any of the treatments. Plant populations are not reported due to planting irregularities in some of the plots.

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

MT = Microtube at planting

ST = Seed Treatment

SB = Smartbox application

Insecticide Screening Concord, NE 2002 Root Ratings

Treatment	Application Method	Rate oz/1000 row ft	Rate lb ai/1000 row ft	Root Rating
Fortress 5 G SB	IF	4.4 oz	0.22	0.1200 a
Regent 4 SC	MT 5 gal	.24 oz	0.13	0.1450 a
Fortress 5 G SB	IF	3.7oz	0.185	0.1525 a
Fortress 3.5 G SB	IF	5.3 oz	0.185	0.1600 a
Aztec 4.67 G SB	TB	3 oz	0.14	0.1650 a
Fortress 3.5 G SB	IF	6.3 oz	0.22	0.1725 a
Fortress 3.5 G SB	IF	4.3 oz	0.15	0.1725 a
Force 3 G	IF	3 oz	0.08	0.1750 a
Aztec 4.67 G SB	IF	3 oz	0.14	0.1800 a
Lorsban 15 G	IF	6 oz	0.90	0.2100 a
Force 3 G	IF	4 oz	0.12	0.2125 a
Lorsban 15 G	IF	8 oz	1.20	0.2225 a
Force 3 G	IF	2 oz	0.06	0.2275 a
Lorsban 15 G	IF	4 oz	0.60	0.2325 a
Aztec 2.1 G	IF	5 oz	0.105	0.2375 a
Fortress 2.5 G	IF	7.4 oz	0.185	0.2450 a
Aztec 2.1 G	IF	6.7 oz	0.14	0.2500 a
Aztec 2.1 G	IF	3.4 oz	0.07	0.2525 a
Leverage 2.7 SE	5 in TB 5 gal	5 oz	1.68 oz AI	0.2550 a
Counter 20 CR	IF	3 oz	0.60	0.2650 a
Clothianidin 600 FS	ST	1.25 mg/kernel		0.2800 a
Prescribe 600 FS	ST	1.35 mg/kernel		0.2825 a
Capture 2 EC	5 in TB 5 gal	0.30 oz	0.0046	0.2875 a
Counter 20 CR	IF	6 oz	1.20	0.2925 a
Counter 20 CR	IF	4.5 oz	0.90	0.2950 a
Lorsban 15 G	TB	8 oz	1.20	0.2975 a
Untreated				0.3175 a
Fortress 5 G SB	IF SB	3 oz	0.15	0.3350 a
Untreated				0.6175 b
Untreated				0.8725 b

Means with the same letter are not significantly different. (LSD = 0.2721; alpha = 0.05)

Precipitation Total

January Total 0.74