scholarly journals The Effectiveness of Bf-Corn Hybrids for Control of European Corn Borer, 1997

1998 ◽  
Vol 23 (1) ◽  
pp. 379-380
Author(s):  
J. T. Shaw ◽  
K. L. Steffey ◽  
M. E. Gray ◽  
J. W. Finger
Keyword(s):  
European Corn Borer ◽  
First Generation ◽  
Compressed Air ◽  
Egg Mass ◽  
Electric Motors ◽  
Corn Hybrids ◽  
Corn Borer ◽  
Leaf Stage ◽  
Corn Plants ◽  
Soil Insecticides

Abstract Each plot consisted of four rows 30 inches wide by 30 ft long with 40 plants per row after thinning. A RCB design with six replications was utilized. There were 10-ft-wide alleys between replications. Two Pounce-treated plots were included as checks in each replication and were averaged for the ANOVA. Manual infestations were made to 15 consecutive plants in each of the middle two rows of each 4-row plot. Manual ECB infestations to simulate the first generation were made on 11 Jul at the 6 corn leaf stage by applying two ECB egg masses (on wax paper) to the whorls of corn plants. Manual ECB infestations to simulate the second generation were made at corn anthesis on 14 Aug by applying one ECB egg mass per leaf axile above and below the ear node. Treatments to the two control plots were applied with a modified John Deere 6000 high-clearance vehicle (HCV). On 17 July, Pounce 1.5 G at a rate of 10 lb product/acre was metered through Noble units mounted in brackets on the rear of the HCV for first generation ECB control. The Noble units were driven with electric motors, and the granules were applied over the whorls in a 7-inch band. The banders were similar to banders on conventional row-planters that are used to deliver soil insecticides. On 19 Aug, Pounce 3.2 EC at a rate of 0.15 lb (AI)/acre was applied with two 8003 TeeJet flat fan nozzles (one per row), in a band over the row, with a compressed-air system calibrated to deliver 9.7 gpa at 20 psi and a speed of 2.5 mph. The height of the nozzles above the whorls was 10 to 12 inches.

scholarly journals The Effectiveness of Br-Corn Hybrids for Control of European Corn Borer, 1996

1997 ◽  
Vol 22 (1) ◽  
pp. 426-427
Author(s):  
J.T. Shaw ◽  
K.L. Steffey ◽  
M.E. Gray ◽  
J.W. Finger
Keyword(s):  
European Corn Borer ◽  
First Generation ◽  
Rating Scale ◽  
Leaf Axil ◽  
Corn Hybrids ◽  
Corn Borer ◽  
Damage Data ◽  
The Mean ◽  
Corn Plants ◽  
Neonate Larvae

Abstract Corn was planted at the University of Illinois Cruse Farm, Champaign, Illinois, on 24 May. The experimental design was a split plot with natural or manual infestation of ECB as the main plots and 5 different B/-corn hybrids and their non-Br isolines as the subplots. Each plot was 4 rows (30-inch) wide X 40 ft long with 35 plants per row (after thinning). Treatments were replicated 5 times. Manual ECB infestations to simulate the first-generation were made on 3 and 6 July at the V7 corn leaf stage by releasing approximately 50 neonate larvae in corn grit into the whorls of corn plants using a ‘bazooka’ applicator. Manual ECB infestations to simulate the second-generation were made at corn anthesis on 7 Aug by applying approximately 25 neonate larvae in corn grit to the leaf exiles above and below the ear node. On 8 Aug, 25 neonate larvae were applied to the ear node and the second leaf axil above the ear node. All manual infestations were made to all plants (70 total) in the middle 2 rows of each plot. On 31 Jul, 20 consecutive plants were rated for leaf feeding by first generation larvae by using the 1 to 10 Guthrie scale. On 9 and lOOct, 15 consecutive plants from 1 of the middle 2 rows were split with a corn knife for evaluation. The number of plants with cavities and the total length of cavities per plant were recorded. Also, the number of live larvae per plant was recorded. The mean percentage of plants with cavities, the mean length of stalk tunneling (in inches) per plant and the mean number of live larvae were determined for each plot. ECB damage to the ear and shank were analyzed separately from the stalk damage data. An ear rating scale of 1 to 3 was used, with 1 being tip damage only, 2 being side damage only, and 3 being tip + side damage on the same ear. Shelled grain weights (yields) were taken from the 15 dissected plants, corrected to 15.5% moisture, and added to the machine harvested weights (moisture corrected) for the remaining plants of the middle 2 rows in each plot.

scholarly journals Evaluation of Efficacy of Selected Conventional and Experimental Insecticides and Bt Hybrids for Control of Corn Earworm and European Corn Borer on Sweet Corn, 1997

1998 ◽  
Vol 23 (1) ◽  
pp. 99-100
Author(s):  
J. T. Shaw ◽  
R. Weinzierl ◽  
J. W. Finger
Keyword(s):  
European Corn Borer ◽  
Sweet Corn ◽  
Corn Earworm ◽  
Compressed Air ◽  
Hollow Cone ◽  
Corn Hybrids ◽  
Corn Borer ◽  
Chemical Treatments ◽  
Untreated Check ◽  
High Clearance

Abstract The tests were arranged in a RCB design with four replications. Each plot consisted of four rows, each being 30 inches wide and 50 ft long. Thirty-foot-wide alleys were established between the four replications. Insecticides were applied to the middle two rows of each plot, leaving two untreated rows between adjoining plots. Twelve insecticide treatments were compared with two Br-sweet corn hybrids (Heritage Bt and Bonus Bt) and their non-Bt isolines to two untreated controls. The 12 chemical treatments and the two untreated checks were planted with the Silver King variety sweet corn. Two untreated check plots were included in each replication and were averaged for the ANOVA. Treatments were applied very four to five days beginning on 8 Aug at 8% silk. All insecticide treatments were applied with a modified John Deere 6000 high-clearance vehicle (HCV) with a rear-mounted boom. Six Conejet (TX VS-8) hollow-cone nozzles (three per row) were calibrated to deliver 30.1 gpa at 40 psi and a speed of 2.5 mph, utilizing a compressed air system. Four nozzles (two per row) were attached to drops and directed the spray towards the ear zone area, a third nozzle (one per row) was mounted directly over the row with the spray being directed into the whorl (tassel) area.

scholarly journals Evaluation of Transgenic Corn Against European Corn Borer, 1997D

1998 ◽  
Vol 23 (1) ◽  
pp. 378-378
Author(s):  
K. R. Ostlie ◽  
J. Luedeman ◽  
P. Price ◽  
M. Jharco ◽  
George Nelson
Keyword(s):  
European Corn Borer ◽  
First Generation ◽  
Row Spacing ◽  
Transgenic Corn ◽  
Tunnel Length ◽  
Corn Hybrids ◽  
Corn Borer ◽  
Leaf Injury ◽  
Normal Production ◽  
Production Practices

Abstract This experiment was conducted to assess the per formance of Bacillus thuringiensis transgenic corn hybrids (<95-day RM) and comparable non-Bt hybrids against a natural ECB infestation in west centra Minnesota. This area contains a mixture of univoltine and multivoltine biotypes. Treatments included 3 non-Bt hybrids (Ciba 4144, NK 2555, NK 3030) anc their isogenic counterparts (Max 357, NK 2555Bt, NK 3030Bt) arranged in a RCB design with 6 replications. Plots, each measuring 50 ft by 8 rows (30-inch row spacing), were planted on 19 May at a rate of 30,000 seeds per acre using a Hiniker Econo Till Planter. Planting preparations, fertilizer and herbicide ap plications followed normal production practices. First generation evaluations on 5 Aug included % of plants with leaf injury, leaf injury ratings (1 to 9 scale) number of tunnels, and tunnel length. Combined effects of univoltine and second generations were measured by examining tunnel number and length, ear anc shank infestations, and overwintering larvae on 20 Sept. Plots were harvested on 10 Oct and yields were corrected to 15.5% moisture.

scholarly journals Evaluation of Transgenic Corn Against European Corn Borer, 1997B

1998 ◽  
Vol 23 (1) ◽  
pp. 376-377
Author(s):  
K. R. Ostlie ◽  
J. Luedeman ◽  
P. Price ◽  
J. Bhend ◽  
B. Potter ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
European Corn Borer ◽  
First Generation ◽  
Row Spacing ◽  
Transgenic Corn ◽  
Tunnel Length ◽  
Corn Hybrids ◽  
Corn Borer ◽  
Leaf Injury ◽  
Loam Soil

Abstract This experiment was conducted to assess the performance of Bacillus thuringiensis (Bt) transgenic corn hybrids (100- and 105-day RM) and comparable non-Bt hybrids against a natural ECB infestation in southwest Minnesota. Plots, each measuring 50 ft by 8 rows (30-inch row spacing), were established in Normania loam soil on 5 May at a rate ol 30,000 seeds per acre. Plots were arranged in a RCB with four replications. ECB injury assessments for first generations on 4 Aug included % shotholing from the center two rows of each plot and leaf injury ratings from 10 plants per plot. Tunnel length and number from both the first generation and univoltine generations were measured simultaneously from 10 plants per plot on 27 Aug. Measurements for second-generation ECB on 15-16 Oct included cumulative tunnel length and number, fall larvae, and ear and shank damage. Plots were harvested on 23 Oct and yields were corrected to 15.5% moisture.

scholarly journals BT Corn Performance Against First- and Second-Generation Infestations of European Corn Borer, 1997

1998 ◽  
Vol 23 (1) ◽  
pp. 374-375
Author(s):  
K. R. Ostlie ◽  
K. M. Helgeson
Keyword(s):  
European Corn Borer ◽  
First Generation ◽  
Second Generation ◽  
Egg Laying ◽  
Row Spacing ◽  
Corn Hybrids ◽  
Corn Borer ◽  
Leaf Injury ◽  
First And Second Generation ◽  
Neonate Larvae

Abstract Six transgenic corn hybrids expressing insecticidal proteins produced by genes from Bacillus thuringiensis (Bt) were evaluated at the Rosemount Experiment Station in separate experiments that targeted first and second generations. The hybrids representing 5 different insertion events, and their non-Bt isolines were evaluated in a RCB design with tour replications. Test hybrids were planted in the center 2 rows of a 4-row plot (22 ft long, 30-inch row spacing). Border rows were planted to NK 4640Bt to preclude inter-plot movement of larvae. Plots were planted on 21 May using a cone planter and thinned to 30,000 plants/A. In view of extensive natural first generation infestation, the second-generation experiment was treated with Warrier 1 E (zeta cypermethrin) @ 3.8 fl oz/acre on 15 Jul. In each plot, 15 consecutive plants were tested for Bt expression and non-expressers were rogued on 29 Jul. The plants intended for first generation evaluation were infested at the V6 with neonate larvae in grits deposited in the whorl on 14 Jul. Heavy natural egg laying from second generation eliminated the need for manually infesting second-generation plots. First generation evaluations included: number and length of tunnels on 21 Aug and % of plants with leaf injury and a leaf injury rating on 24 Sep. On 9 Oct the second generation measurements were recorded: number of overwintering larvae, tunnel number and length, and shank and ear damage.

scholarly journals Evaluation of Transgenic Corn Against European Corn Borer, 1997C

1998 ◽  
Vol 23 (1) ◽  
pp. 377-378
Author(s):  
K. R. Ostlie ◽  
J. Luedeman ◽  
P. Price ◽  
K. Helgeson ◽  
J. Rowe
Keyword(s):  
European Corn Borer ◽  
First Generation ◽  
Row Spacing ◽  
Silt Loam ◽  
Tunnel Length ◽  
Corn Hybrids ◽  
Corn Borer ◽  
Leaf Injury ◽  
East Central ◽  
Loam Soil

Abstract This experiment was conducted to assess the performance of Bacillus thuringienis (Bt) trangenic corn hybrids (100- and 105-day RM) and comparable non-Bt hybrids against a natural ECB infestation in east central Minnesota. Plots, each measuring 50 ft by 8 rows (30- inch row spacing), were established in Dakota silt loam soil on 19 May at a rate of 32,000 seeds per acre. Plots were arranged in a RCB with four replications. ECB injury assessments for first generation on 30 Jul included % shotholing from the center two rows of each plot and leaf injury ratings (1 to 9 scale) from 10 plants per plot. Tunnel length and number from first generation were measured from 10 plants per plot on 13-15 Aug. Measurements for second generation ECB on 14, 20, & 27 Oct included cumulative tunnel length and number, fall larvae, ear and shank damage from 10 plants per plot. Plants were harvested on 6 Nov and yields were corrected to 15.5% moisture.

First Generation European Corn Borer Larvicide Trial, 1994

1995 ◽  
Vol 20 (1) ◽  
pp. 169-169
Author(s):  
Mike Haas ◽  
Doug Landis
Keyword(s):  
European Corn Borer ◽  
First Generation ◽  
Corn Borer
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