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 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, 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.

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 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.

Influence of Transgenic Corn Expressing Insecticidal Protein of Bacillus thuringiensis Berliner on Natural Populations of Corn Earworm (Lepidoptera: Noctuidae) and Southwestern Corn Borer (Lepidoptera: Crambidae)

2006 ◽  
Vol 41 (3) ◽  
pp. 221-231 ◽  
Author(s):  
Kerry C. Allen ◽  
Henry N. Pitre
Keyword(s):  
Bacillus Thuringiensis ◽  
Helicoverpa Zea ◽  
Larval Growth ◽  
Natural Populations ◽  
Corn Earworm ◽  
Bt Corn ◽  
Transgenic Corn ◽  
Diatraea Grandiosella ◽  
Corn Hybrids ◽  
Corn Borer

A 2-yr study was conducted to measure the influence of transgenic corn, Zea mays L., expressing the CrylAb endotoxin of Bacillus thuringiensis (Berliner) (Bt) by means of Event MON810 on natural populations of Helicoverpa zea (Boddie) and Diatraea grandiosella (Dyar). The studies were conducted at Leland and Morgan City, MS, in 1999 and at Morgan City in 2000. Although total numbers of H. zea larvae were not significantly different on transgenic corn hybrids compared with their near-isogenic parent lines, fewer large larvae were found on the transgenic hybrids. Differences in H. zea larval growth were noticeable when larvae fed on Bt corn vs non-Bt corn. The delay in larval growth for insects within a single generation, which could possibly result in asynchronous mating between insecticide resistant and susceptible insects, was observed for larvae feeding on plants expressing the Bt toxin. Diatraea grandiosella caused limited damage to the transgenic corn hybrids compared with their near-isogenic parent lines. Yields were not significantly greater for the Bt corn hybrids compared with their near-isogenic parent lines. Yields were not significantly greater for the Bt corn hybrids compared with the near-isogenic, non-Bt corn parents; however, there was a trend toward higher yields for Bt hybrids compared with their near-isogenic non-Bt parents.

Field Evaluation of European Corn Borer Control in Progeny of 173 Transgenic Corn Events Expressing an Insecticidal Protein from Bacillus thuringiensis

Crop Science ◽  
1995 ◽  
Vol 35 (2) ◽  
pp. 550 ◽  
Author(s):  
Charles L. Armstrong ◽  
Gregory B. Parker ◽  
Jay C. Pershing ◽  
Sherri M. Brown ◽  
Patricia R. Sanders ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
European Corn Borer ◽  
Field Evaluation ◽  
Insecticidal Protein ◽  
Transgenic Corn ◽  
Corn Borer

Transgenic Corn Expressing a Cry9C Insecticidal Protein from Bacillus thuringiensis Protected from European Corn Borer Damage

Crop Science ◽  
1997 ◽  
Vol 37 (5) ◽  
pp. 1616-1624 ◽  
Author(s):  
Stefan Jansens ◽  
Adri Vliet ◽  
Catherine Dickburt ◽  
Linda Buysse ◽  
Carla Piens ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
European Corn Borer ◽  
Insecticidal Protein ◽  
Transgenic Corn ◽  
Corn Borer

Managing Colorado Potato Beetles (Coleoptera: Chrysomelidae) and European Corn Borers (Lepidoptera: Pyralidae) in Potato with Foliar Applications of Bacillus thuringiensis Berliner

2000 ◽  
Vol 35 (4) ◽  
pp. 373-384 ◽  
Author(s):  
Brian A. Nault ◽  
John Speese
Keyword(s):  
Bacillus Thuringiensis ◽  
Colorado Potato Beetle ◽  
European Corn Borer ◽  
First Generation ◽  
Solanum Tuberosum L ◽  
Potato Crop ◽  
Corn Borer ◽  
Corn Borers ◽  
Potato Beetle ◽  
Leptinotarsa Decemlineata Say

Application timing and rate combinations of Bacillus thuringiensis Berliner used for protecting Irish potato, Solanum tuberosum L., from defoliation by the Colorado potato beetle, Leptinotarsa decemlineata (Say), and stem injury by the European corn borer, Ostrinia nubilalis (Hübner), were investigated. Significant reductions in defoliation levels during bloom, populations of first-generation potato beetle adults, and the percentage of stems injured by corn borers at the end of the season in B. thuringiensis-treated potato were considered criteria for a successful management strategy. Although Colorado potato beetle infestations were managed effectively with B. thuringiensis, European corn borer populations were not reduced to a commercially acceptable level. In each of 3 yrs, neither an increase in the number of applications (from 1 to 4) nor an increase in rate (from 0.9 to 3.8 liters/ha) of B. thuringiensis subsp. kurstaki improved the level of corn borer control. In contrast, results indicated that 1 application of B. thuringiensis subsp. tenebrionis, timed when there was >1 large potato beetle larva per stem, using a 4.7 liters/ha rate protected the potato crop during the bloom stage. However, this strategy may not be sufficient to prevent significant levels of defoliation by first-generation potato beetle adults during post-bloom or reduce the size of this population, which will infest next season's crop. For this reason, the B. thuringiensis subsp. tenebrionis timing and rate regimen described above may be most effective in fields where the overwintering potato beetle population is predicted to be low to moderate (e.g., <1 adult per 5 stems), whereas two applications may be most effective in fields where densities are greater.

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