scholarly journals Insecticide Applied Aerially for Control of First Generation European Corn Borer, 1994

1995 ◽  
Vol 20 (1) ◽  
pp. 185-185
Author(s):  
John F. Witkowski

Abstract The cornfield was located in Cedar county, northwest of the town of Hartington, NE. Six black headed egg masses were infested onto 30 marked plants (3, ten plant subsamples) per treatment on 24 Jun. A Cessna 188 Ag Truck was used to make the applications on 30 Jun. Aerial treatments were flown on in a strip plot design. On 9 Aug, all artificially infested plants were dissected from tassel to ground and examined for borer cavities.

1996 ◽  
Vol 21 (1) ◽  
pp. 234-235
Author(s):  
John Witkowski ◽  
Jerry Echtenkamp

Abstract The cornfield was located in Cedar County, northwest of the town of Hartington, NE. Two treatments and an untreated check were arranged in a strip plot design with one replication. Six black headed egg masses were infested onto 30 marked plants (3, ten plant subsamples) per treatment on 6 Jul. A Cessna 188 Ag Truck was used to make the applications on 13 Jul. On 18 Aug, all artificially infested plants were disected from tassel to ground and examined for corn borer cavities. Data were analyzed using analysis of variance procedures. Treatment means were separated using LSD procedures.


1995 ◽  
Vol 20 (1) ◽  
pp. 129-129
Author(s):  
Robert A. Suranyi ◽  
Edward B. Radcliffe ◽  
Matthew P. Samuelson ◽  
Galen C. Thompson

Abstract Potatoes were planted 17 May at the Research Farm of the Red River Valley Potato Growers Association. Plots were four rows wide, 60 ft long, with 38 in rows and 12 in between plants. Plots were separated on all sides by 6.3 ft of cultivated soil. The experiment had a complete randomized plot design with four replications. Egg masses were flagged 15 Jun and checked daily. Thirty percent egg hatch was estimated to have occurred 22 Jun, but heavy rains and wet field conditions delayed first application of insecticidal sprays until 24 Jun. Subsequent spray applications were made 5, 12 Jul, and 8 Aug. Jun and Jul sprays were targeted against first generation larvae, Aug application against summer generation adults. All applications were made using a tractor-mounted boom sprayer, with a single Teejet nozzle over each row. Sprays were applied in 40 gal of water/acre at 40 psi. Egg masses, small larvae (1st and 2nd instar), large larvae (3rd and 4th instar), and adults were counted 27 Jun, 7, 14 Jul, and 10 Aug on 20 randomly selected plants from the two middle rows of each plot. Tuber yields were estimated by mechanical harvesting one row per plot 2 Sept. Defoliation data were recorded at each evaluation and expressed as mean percent of defoliation across sampling dates. The average number of insect counts across sampling dates are presented in the table. Best control resulted from the use of Furadan, Imidan, and Capture. Yield differences among treatments were not significantly correlated with any measure of insect numbers. Parts of the field were saturated for an extended period of time by heavy Jun rains, which adversely affected yields in all plots. Tuber yields ranged from 136.7 to 207.4 cwt/acre.


1995 ◽  
Vol 20 (1) ◽  
pp. 169-169
Author(s):  
Mike Haas ◽  
Doug Landis

1992 ◽  
Vol 27 (3) ◽  
pp. 239-250
Author(s):  
Clifford B. Keil ◽  
Christopher Tipping

Hybrid matings of two Ostrinia nubilalis (Hübner) (Lepidoptera: Pyralidae) colonies (N and O), established in the laboratory a year apart, demonstrated positive heterosis in the F1 generation as indicated by increases in pupal weight (6%), number of egg masses per female (65%) and number of eggs per female (77%) as compared to intra-colony crosses in mass matings. In contrast, pupation date, an indicator of development time, was intermediate in the hybrids relative to the parental colonies. There was also a 37% increase in the numbers of eggs/female and a 45% increase in egg masses/female in the hybrid parental cross. We investigated this stimulation of oviposition in single female, reciprocal crosses. Oviposition stimulation was directional with the cross of N colony males x O colony females exhibiting significantly higher numbers of total eggs/female and egg masses/female on a daily basis. Colony O females in this cross laid more large egg masses than females in other crosses. Data from individual female crosses demonstrated that egg production in hybrid mass mating experiments was consistent with random mating of males and females from both colonies.


1963 ◽  
Vol 95 (12) ◽  
pp. 1285-1292 ◽  
Author(s):  
C. A. Barlow

AbstractA method of forecasting the size of first-generation or summer infestations of Ostrinia nubilalis in Kent County, Ontario, is described. A function is derived from partial regression analysis relating the estimated size of the expected summer infestation to (1) the number of females caught in a light-trap during the first or spring flight, and (2) average rainfall per day during the first flight. The function explains 94% of the observed variation in estimated size of first-generation infestations in this area between 1947 and 1961. A means of categorizing the estimated size of the predicted infestation based on the frequency distribution of previously estimated infestations is also described. Methods of sampling and estimating population size and the applicability of the predictive equation to other environments are discussed.


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