scholarly journals Efficacy of Bacillus Thuringensis for Control of Lepidopterous Larvae in Lettuce, 1994

1996 ◽  
Vol 21 (1) ◽  
pp. 120-121
Author(s):  
D. L. Kerns

Abstract Lettuce was direct seeded into double-rows on 42-in beds on Sep 4 at the Yuma Valley Agricultural Center, Yuma, AZ. Plots were four beds wide by 30 ft long. Each plot was bordered on each side by two blank beds. Plots were arranged in a RCB design with four replicates. Treatments were applied using a tractor-mounted sprayer with two TX-18 hollow cone nozzles per bed, calibrated to deliver 60 gal/acre at 300 psi. All treatment applications included Dyne-Amic spreader-sticker at 0.25% v/v. Treatments were applied on Sep 28, Oct 10 and Oct 17. Evaluations were made four to six days after treatment (Sep 26, Oct 3, Oct 10 and Oct 17) by randomly selecting ten plants per plot and counting the number of live large (>2nd instar) BAW and CL larvae. Data were analyzed for treatment differences using ANOVA and an F protected LSD.

1996 ◽  
Vol 21 (1) ◽  
pp. 119-119
Author(s):  
D. L. Kerns

Abstract Lettuce was direct seeded into double-rows on 40-in beds on 6 Sep at the Yuma Valley Agricultural Center, Yuma, AZ. Plots were four beds wide by 30 ft long. Each plot was bordered on each side by two blank beds. Plots were arranged in a RCB design with four replicates. Treatments were applied using a tractor-mounted sprayer with three TX-6 hollow cone nozzles per bed, calibrated to deliver 40 gal/acre at 200 psi. All treatment applications included Kinetic spreader-sticker at 0.05% v/v. Treatments were applied on 21 Sep, 28 Sep, 6 Oct, 14 Oct, 19 Oct and 26 Oct. Evaluations were made five days after each treatment (26 Sep, 3 Oct, 11 Oct, 19 Oct, 24 Oct and 31 Oct) by randomly selecting 25 plants per plot and counting the number of live small (1st and 2nd instar) and large (>2nd instar) BAW and CL larvae. Data were analyzed for treatment differences using ANOVA and an F protected LSD.


1997 ◽  
Vol 22 (1) ◽  
pp. 135-135
Author(s):  
D. L. Kerns ◽  
T. Tellez

Abstract Lettuce was direct seeded into double-rows on 42-in beds on 9 Sep at the Yuma Valley Agricultural Center, Yuma, AZ. Plots were four beds wide by 30 ft long. Each plot was bordered on each side by two blank beds. Plots were arranged in a RCB design with four replicates. Treatments were applied using a tractor-mounted sprayer with three TX-6 hollow cone nozzles per bed, calibrated to deliver 40 gpa at 200 psi. All treatment applications included Crocker’s Fish Oil at 10 oz/acre and Kinetic non-ionic surfactant at 0.10% v/v. Treatments were split into two regimes (early-season and late-season). The early-season applications were applied on 1 Oct, 11 Oct and 17 Oct. The late-season applications were applied on 25 Oct, 31 Oct, 5 Nov and 18 Nov. Evaluations were made five to six days after each application (7 Oct, 16 Oct, 22 Oct, 30 Oct, 4 Nov, 12 Nov and 25 Nov) by randomly selecting 10 plants per plot and counting the number of live small (1st and 2nd instar) and large (>2nd instar) CL larvae. Data were analyzed for treatment differences using ANOVA and an F protected LSD.


1996 ◽  
Vol 21 (1) ◽  
pp. 99-99
Author(s):  
K. A. Sorensen ◽  
C. Wade Holloway

Abstract ‘Gourmet’ cabbage was direct seeded in early Mar near Weeksville, NC. Single row plots 10 ft. long on 42 inch centers were replicated 4 times in a RCB design. Alleys of 5 ft. were used between replicates. Treatments were applied with a CO2 pressurized backpack sprayer using a single hollow cone nozzle (18X) operating at 60 psi to deliver 54.5 gal/acre. Applications with Triton AG-98 (spreader) were made with all treatments 2, 9, 16 and 23 May. Visual estimates of foliar damage and insect counts were made 9, 16, 23 and 30 May. No CL were present on 9 and 16 May.


1997 ◽  
Vol 22 (1) ◽  
pp. 137-137
Author(s):  
J. V. Edelson ◽  
M. Peters

Abstract A commercial production field of mustard was used for this trial. Plants were grown in 6 row beds on 6 ft centers. The field was direct seeded in Apr approximately 1 mile west of Webbers Falls, OK. Small plots were delimited on one edge of the field. The experimental design was a RCB with 4 replicates and 7 treatments. Insecticide applications were made on 23 and 29 May using a bicycle tire mounted sprayer with 4 hollow cone nozzles (TXVS26) per bed applying 40 gpa solution at 42 psi. Plots were 1 bed wide and 20 ft long with 5 ft alleys between plots. Insect populations were surveyed by examining 5 plants per plot on 29 May (prior to the second application of insecticides) and 3 Jun to determine treatment effects.


1998 ◽  
Vol 23 (1) ◽  
pp. 142-143
Author(s):  
Susan E. Webb

Abstract Insecticides specific for lepidopterous pest-were compared with a standard, Thiodan, and an untreated check for control of pickleworm. Squash was direct seeded on 1 Apr at the Central Florida Research and Education Center, Leesburg, FL. Each plot consisted of four 25-ft rows, 6 ft apart with plants spaced 2.5 ft apart. Treatments were replicated four times in an RCB design. All chemicals were applied with a 2-row tractor-mounted boom sprayer with 18 Albuz (lilac) ceramic hollow-cone nozzles spaced 8 inches apart, delivering 133 gpa at 200 psi. Latron CS-7, a surfactant, was tank-mixed with Confirm and RH-2485 at a concentration of 0.12% vol:vol. Treatments were applied weekly from 14 May to 11 Jun. Fruits were harvested, separated into marketable and damaged, counted, and weighed three times per week from 12 May to 16 Jun. An analysis of variance and a mean separation test (WD) were used to determine significant differences among treatments.


1998 ◽  
Vol 23 (1) ◽  
pp. 138-139 ◽  
Author(s):  
David Riley

Abstract Fresh-market type ‘Fall Green’ spinach, was direct seeded on 11 Oct 1995 in 100-cm-width beds and maintained with standard cultural practices at Weslaco, TX. Plots consisted of two rows by 10 m and were arranged in a RCB design with six treatments and four replicates. Admire (imidacloprid) was applied at planting as an 8-cm banded spray in the seed furrow. All other insecticide treatments were foliar sprays which were initiated when aphid numbers exceeded 1 per leaf. Spray applications were made on January 16, 23 and February 14 with three TX6 hollow-cone tips (Spraying Systems Company) per row. The spray volume was 284 ]/ha. Aphids were counted on one expanded leaf per plant on 5 plants per plot. An additional destructive sample was taken at harvest on 8 and 16 Feb to determine the number of gpa per 10 leaves per plot and number of root aphids per 5 mechanically extracted tap roots. Data were subjected to analysis of variance and LSD tests for separation of treatment means.


1995 ◽  
Vol 20 (1) ◽  
pp. 93-93
Author(s):  
J. C. Palumbo

Abstract Lettuce was direct seeded into double-row beds on 12 Sep at the Yuma Valley Agricultural Center, Yuma, AZ. Plots consisted of four, 45 ft long beds spaced 42 inches apart and bordered on each side by two unplanted beds. Plots were arranged in a completely randomized block design with 4 replicates. Foliar treatments were applied on 7 and 12 Oct with a CO2-powered backpack sprayer with a two-bed boom, having one nozzle per row (TX 12 hollow cone), and delivering 20.5 gal/acre at 40 psi. Latron CS-7 spreader-sticker was applied at 0.125% v/v with all treatments. Evaluations were made on 7, 12, and 17 Oct by selecting 15 plants per replicate, removing all leaves, and counting the total number of small (1st and 2nd instars) and large (>2nd instar) BAW, CL and TBW live larvae. Data were analyzed for treatment differences using ANOVA and a protected LSD.


1997 ◽  
Vol 22 (1) ◽  
pp. 194-194
Author(s):  
S. E. Webb

Abstract Watermelon was direct-seeded on 30 Mar at the Central Florida Research and Education Center, Leesburg, FL. Each plot consisted of four 35-ft rows, 7 ft apart with plants spaced 2.5 ft apart. Treatments were replicated four times in an RCB design. Fungicide (mancozeb or chlorothalonil) was applied weekly, usually 2 d after insecticides. All materials were applied with a 2-row tractor-mounted boom sprayer with 18 Albuz (lilac) ceramic hollow cone nozzles, spaced 8 inches apart, delivering 178 gpa at 400 psi or 133 gpa at 200 psi (CGA-215944 and Thiodan only). Silwet (0.02% or 0.03%, vohvol) was tank-mixed with Mycotrol. CGA-215944 was tested for aphid control only and was applied when the number of aphids exceeded five per leaf (high rate on 24 May only, low rate on 24 May and 7 Jun). All other treatments were applied on 24 May, 1,7, 13, and 20 Jun except Thiodan which was not applied on 24 May. Small whitefly nymphs (first and second instars) and large nymphs (third and fourth instars, pupae) were counted and summed on three 0.6-inch diam leaf disks cut from each of 20 leaves per plot for 5 weeks, beginning on 29 May and ending on 26 Jun. Aphids were counted on whole leaves. A square root transformation was used to stabilize the variance of counts for analysis. A two-way ANOVA and a mean separation test (Waller-Duncan k-ratio) were used to determine differences among treatments.


1998 ◽  
Vol 23 (1) ◽  
pp. 81-82
Author(s):  
David G. Riley

Abstract Fresh-market cabbage was direct seeded on 11 October, 1995 at Weslaco, TX in 100-cm-wide beds and maintained with standard cultural practices. Plots consisted of two rows by 10.7 m and were arranged in a RCB design with sixteen treatments and four replicates. Spray applications were made on 2 Nov, 29 Nov, 14 Dec 1995, and 17 Jan 1996 with three hollow-cone tips per row. Applications were made with 284 1/ha of water. Cabbage loopers, diamondback moth larvae, and beet armyworms were counted on five whole plants per plot. Cabbage heads were harvested on 30 Jan, 5 Feb, and 21 Feb and evaluated for damage from 0 = none to 4 = severe damage to wrapper leaves and/or head. Harvested weight of cabbage was based on an average of two harvests from 5 plants each. Analysis of variance and LSD tests for separation of treatment means were calculated from averages over all sample dates.


Author(s):  
William Krakow

An electronic device has been constructed which manipulates the primary beam in the conventional transmission microscope to illuminate a specimen under a variety of virtual condenser aperture conditions. The device uses the existing tilt coils of the microscope, and modulates the D.C. signals to both x and y tilt directions simultaneously with various waveforms to produce Lissajous figures in the back-focal plane of the objective lens. Electron diffraction patterns can be recorded which reflect the manner in which the direct beam is tilted during exposure of a micrograph. The device has been utilized mainly for the hollow cone imaging mode where the device provides a microscope transfer function without zeros in all spatial directions and has produced high resolution images which are also free from the effect of chromatic aberration. A standard second condenser aperture is employed and the width of the cone annulus is readily controlled by defocusing the second condenser lens.


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