scholarly journals Efficacy of Pyrethroids and Lannate on Lepidopterous Larvae in Lettuce, 1995

1996 ◽  
Vol 21 (1) ◽  
pp. 124-124
Author(s):  
J. C. Palumbo

Abstract Lettuce was direct seeded into double-row beds on 9 Sep at the Yuma Valley Agricultural Center, Yuma, Az. Each plot consisted of four, 30 ft long beds spaced 42 inches apart and bordered on each side by an untreated bed. Plots were arranged in a RCB design with 4 replicates. Foliar applications were made on 22 and 30 Sep and with a hand-held CO2 sprayer operated at 60 psi, delivering 20 gal/acre. Spreader-sticker (Kinetic) was included in all spray treatments at a rate of 0.25% of the total volume. Insecticide efficacy was determined by counting the total number of small (1st and 2nd instars) and large (>2nd instar) BAW and CL larvae on 20 randomly selected lettuce plants per replicate. Insect counts were conducted the day of application, 22 and 30 Sep, and at 3 days after treatment, 30 Sep and 3 Oct. Treatment differences among means were estimated with the Ryan-Einot-Gabriel-Welsch multiple F test.

1997 ◽  
Vol 22 (1) ◽  
pp. 86-86
Author(s):  
J. C. Palumbo

Abstract Broccoli was direct seeded into double-row beds on 21 Sep at the Yuma Valley Agricultural Center, Yuma, AZ. Each plot consisted of four, 30 ft long beds spaced 42 inches apart and bordered on each side by an untreated bed. Plots were arranged in a CRB design with 4 replicates. Foliar applications were made on 30 Oct and 4 Nov with a hand-held CO2 sprayer operated at 50 psi, delivering 20 gpa. Spreader-sticker (Kinetic) was included in all spray treatments at a rate of 0.125% of the total volume. Insecticide efficacy was determined by counting the total number of small (1 st and 2nd instars) and large (>2nd instar) CL larvae on 5 randomly selected broccoli plants per replicate. A pre-treatment sample was taken on 29 Oct and evaluations were made 5 DAT on 4 and 9 Nov. Data were analyzed as a 1-way ANOVA using a protected LSD F test to distinguish treatment mean differences.


1998 ◽  
Vol 23 (1) ◽  
pp. 107-108
Author(s):  
J. C. Palumbo ◽  
F. J. Reyes

Abstract Lettuce was direct seeded on 13 Sep. at the University of Arizona Yuma Agricultural Center. Each plot consisted of four, 60-ft-long beds spaced 42 inches apart and bordered on each side by 2 untreated beds. Plots were arranged in a CRB design with 4 replicates. Prior to application of treatments, a Lannate (0.75 lb (AI)/acre) and Karate (0.3 lb (AI)/acre) spray was applied to all plots on 27 Sep to control lepidopterous larvae. Foliar treatments were applied on 10 and 17 Oct with a tractor drawn sprayer operated at 150 psi, delivering 45 gpa. No spreader-sticker was added to any of the spray treatments. Insecticide efficacy was determined by randomly selecting 10 lettuce plants in each replicate and placing them in emergence containers for 3-4 weeks to allow for pupation and emergence of liriomyza and parasitoid adults. Adults were counted and their species recorded. Data were analyzed as a one-way ANOVA using a protected LSD F test to distinguish treatment mean differences.


1997 ◽  
Vol 22 (1) ◽  
pp. 116-116
Author(s):  
J. C. Palumbo

Abstract Cauliflower was direct seeded into on 21 Sep at the Yuma Valley Agricultural Center, Yuma, Az. Each plot consisted of four, 30-ft-long beds spaced 42 inches apart and bordered on each side by two untreated beds. Plots were arranged in a CRB design with 4 replicates. Foliar applications were made on 10 and 14 Oct with a hand-held CO2 sprayer operated at 50 psi, delivering 20 gpa. Spreader-sticker (Kinetic) was included in all spray treatments at a rate of 0.125% of the total volume. Insecticide efficacy was determined by counting the total number of small (1 st and 2nd instars) and large (>2nd instar) CL on 5 randomly selected plants replicate. Data were analyzed as a 1-way ANOVA using a protected LSD F test (P = 0.05) to distinguish treatment mean differences.


1997 ◽  
Vol 22 (1) ◽  
pp. 137-137 ◽  
Author(s):  
J. C. Palumbo ◽  
C. H. Mullis ◽  
F. J. Reyes

Abstract Lettuce was direct seeded on 29 Nov at the Yuma Valley Agricultural Center, Yuma, AZ. into double row beds on 42 inch centers and stand establishment achieved using overhead sprinkler irrigation. Subsequent irrigations and chemigations were made with sub-surface (6-8”) drip irrigation. Plots consisted of 4 beds, 50 feet long with a two bed buffer between the plots. Plots were arranged in a RCB design with four replications. The four Admire 2F chemigation treatments were applied once 54 d after planting (23 Jan) through the drip system during the last hour of the irrigation run. The two Metasystox-R chemigation treatments were applied through the drip three times on 23 Jan, 1 and 8 Feb. The foliar Metasystox-R + Capture treatment was applied at 60 PSI in 20 gpa total volume on 23 Jan, 1 and 8 Feb. Insect data were collected only from the inner two beds of each plot. Aphid densities were estimated bi-weekly by sampling 10 plants per replicate and counting the total number of aphids per plant. Data were analyzed as a 1-way ANOVA using a protected LSD F test to distinguish treatment mean differences.


1996 ◽  
Vol 21 (1) ◽  
pp. 89-89
Author(s):  
J. C. Palumbo

Abstract Broccoli was direct seeded into double-row beds on 19 Sep at the Yuma Valley Agricultural Center, Yuma, Az. Each plot consisted of four, 30 ft long beds spaced 42 inches apart and bordered on each side by an untreated bed. Plots were arranged in a RCB design with 4 replicates. A single foliar application was made on 15 Oct with a hand-held CO2 sprayer operated at 60 psi, delivering 20 gal/acre. Spreader-sticker (Kinetic) was included in all spray treatments at a rate of 0.25% of the total volume. Insecticide efficacy was determined by counting the total number of small (1st and 2nd instars) and large (> 2nd instar) BAW and CL larvae on 10 randomly selected broccoli plants per replicate. Insect counts were conducted the day of application, 15 Oct, and at 4 days after treatment, 19 Oct (4 DAT).


1996 ◽  
Vol 21 (1) ◽  
pp. 103-104
Author(s):  
J. C. Palumbo ◽  
C. H. Mullis

Abstract Cantaloupes were direct seeded on 9 Mar into pre-irrigated beds spaced 80 inches apart at the University of Arizona, Yuma Valley Agricultural Center, Yuma, AZ. Plots consisted of 4 beds, 60 ft long with a 13 ft buffer between plots. Plot preparation and seasonal maintenance followed local practices. Plots were established and insecticide incorporated with furrow irrigation. Plots were arranged in a RCB design with 4 replicates. Foliar applications were made with a tractor drawn sprayer that delivered 48 gpa at 320 psi on 13 Apr, 3, 17 May. Adult efficacy was assessed by counting the number of adults per leaf from each of 10 leaves per plot, 1 day before treatments were applied and 4, and 7 days after treatment. Because of heterogeneity of mean variances, insect data was first transformed (log10 x + 1) before analysis of variance. Treatment differences among means were estimated with the Ryan-Einot-Gabriel-Welsch multiple F test.


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.


1996 ◽  
Vol 21 (1) ◽  
pp. 104-104 ◽  
Author(s):  
J. C. Palumbo ◽  
C. H. Mullis ◽  
F. J. Reyes

Abstract Cantaloupes were direct seeded on 23 Aug into beds spaced 80 inches apart at the University of Arizona, Yuma Valley Agricultural Center, Yuma, AZ. Plots consisted of 4 beds, 50 ft long with a 20 ft buffer between plots. Plot preparation and seasonal maintenance followed local practices. Plots were arranged in a RCB design with 4 replicates. Admire 2F treatments were applied 2 in. sub-seed furrow by injecting the material into the beds with long, narrow shanks in 20 GPA total volume of water before seeding. The Gaucho seed treatment was formulated at a rate of 35 g AI of imidacloprid/kg of cantaloupe seed. Foliar applications were made with a tractor drawn sprayer that delivered 48 gpa at 320 psi. The Capture+Thiodan mixture was applied on 8, 12, 20, and 27 Sep. Provado and Pyriproifen were applied on 8, 12, 20, 27 Sep and 7, 16 Oct. SPWF densities were estimated by counting the number of eggs and nymphs on two-cm2 disk sections taken from each of 20 leaves per plot on 7 Sep, 28 Sep and 2 Nov. Because of heterogeneity of mean variances, insect data was transformed (log10 x + 1) prior to analysis. Treatment differences among means were estimated with the Ryan-Einot-Gabriel-Welsch multiple F test.


1969 ◽  
Vol 08 (04) ◽  
pp. 215-219
Author(s):  
G. A. Lienert ◽  
H. Schulz
Keyword(s):  

Es wird eine Übersicht über derzeit verfügbare verteilungsfreie Dispersionstests gegeben. Da bisher noch kein voll effizienter Zwei-Stichproben-Dispersionstest auf Randomisierungsbasis — entsprechend dem Randomisierungstest von Fisher für Lokationsunterschiede —• vorliegt, wurde ein solcher entwikkelt und an einem Beispiel demonstriert.Das Rationale beruht darauf, daß die Meßwerte eines Zwei-Stichproben-Vergleiches — nach den Regeln der Kombinatorik — in allen möglichen Kombinationen angeordnet werden und für jede Kombination der zugehörige Varianzquotient (F-Bruch) berechnet wird. Auf diese Weise erhält man eine stichprobenspezifische Prüfverteilung. Die Prüfgröße ergibt sich aus der Zahl der F-Werte, die den beobachteten F-Wert erreichen oder übersteigen. Die Alternativhypothese kann einoder zweiseitig formuliert werden.Vorteile des Tests: Er spricht nur auf Unterschiede der Dispersion zweier Stichproben an, und seine relative asymptotische Effizienz ist gleich eins. Nachteilig wirkt sich der erhebliche Rechenaufwand aus, wenn keine Rechenanlage zur Verfügung steht.


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