CORN (Field): Zea Mays L. (Dekalb 641)

European corn borer; Ostrinia nubilalis (Hubner)

Jerry Echtenkamp & Tom Hunt                                                             
Haskell Agricultural Laboratory
57905 866 Road, Concord, NE 68728
(402)-584-2261

CONTROL OF EUROPEAN CORN BORER IN WHORL STAGE CORN, 2000

The experimental design was randomized complete block with 7 insecticide treatments and an untreated check replicated 4 times. Single row plots were 50 feet in length and at 30 inch spacings. Corn was no-till planted into soybean residue on 30 Apr. Liquid insecticides were applied with a back-pack sprayer directing the spray solution into the whorl and calibrated to deliver 20 gallons of water/acre at 30 psi. The planting time treatment of Regent 4SC was applied in-furrow via microtubes. Pounce 1.5G granular insecticide was applied with a shaker can.

On 26 Jun, six black headed ECB egg masses were placed in each whorl of ten marked plants per plot row. Whorl treatments were applied four d later on 30 Jun. On 20 Jul, the ten marked plants in each replicate were dissected from tassel to ground, and the number of corn borer cavities recorded. Results were analyzed using analysis of variance procedures. Treatment means were separated using LSD procedures

All treatments resulted in significantly fewer cavities compared with the untreated check. Number of cavities in plots treated with Regent 4SC applied in-furrow at planting were statistically different than the untreated check, but had significantly higher cavities than all other insecticide treatments.

	Rate (lbs ai/acreor
Treatment/form.	fluid oz /acre)	cavities/plant^2
Regent 4SC	0.06 lbs ai	0.15 a
Pounce 1.5G	0.15 lbs ai	0.33 a
Intrepid 2F^3	0.12 lbs ai	0.45 a
Tracer 4SC	2.00 fluid oz	0.48 a
Tracer 4SC	1.00 fluid oz	0.55 a
Warrior-T 1E	3.20 fluid oz	0.60 a
Regent 4SC	0.13 lbs ai (inf. at 1GPA)^1	2.50 b
Untreated	------------	3.65 c
1Applied in-furrow at planting with microtubes. 2Means followed by the same letter are not significantly different (P>0.05) using LSD. 3Latron CS-7 at 0.25% v/v additive was included.

Corn (Field):Zeamays L. (Dekalb 567)
European corn borer; Ostrinianubilalis (Hubner)

Jerry Echtenkamp & Tom Hunt
Haskell Agricultural Laboratory
57905 866 Road, Concord, NE 68728
(402)-584-2261

CONTROL OF SECOND GENERATION EUROPEAN CORN BORER, 2000

Foliar treatments of registered and non-registered insecticides for second generation European corn borer control were applied to irrigated corn plots on 4 Aug. Liquid formulated insecticides were applied with a Hahn Hi-Boy calibrated to deliver 17 gpa at 30 psi. Two d prior to application, six black headed egg masses on paper disc were pinned to the middle portion of 10 marked corn plants in each replicate. Experimental design was RCB with four replications. On 15 Sep, the infested plants were dissected from tassel to ground, and the number of corn borer larvae recorded. Results were analyzed using analysis of variance procedures. Treatment means were separated using LSD procedures.

All treatments resulted in significantly fewer larvae per plant than the untreated check. Results were variable among treatments.

Treatment/form.	Rate (fluid oz formul. or lbs ai/acre)	larvae/plant^1
Capture 2E (2 apps)^2	0.040 + 0.040 lbs ai	0.25 a
Capture 2E	0.080 lbs ai	0.28 a
Capture 2E	0.040 lbs ai	0.43 ab
Tracer 4SC	2.000 fluid oz	0.48 abc
Warrior-T 1E	3.200 fluid oz	0.48 abc
Intrepid 2F^3	0.060 lbs ai	0.90 bcd
Baythroid 2E	2.400 fluid oz	1.00 cde
Intrepid 2F^3	0.120 lbs ai	1.03 cde
Tracer 4SC	1.000 fluid oz	1.05 de
Mustang 1.5E	0.044 lbs ai	1.55 ef
Mustang 1.5E	0.050 lbs ai	1.80 f
Untreated	------	3.65 g

1Means followed by the same letter are not significantly different
Second application was seven days later
August 11 Latron CS-7 at 0.25% v/v additive was included.