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(E8) CABBAGE: Brassica oleracea capitata (L.) 'Headstart' EVALUATION OF DPX-E2Y45 FOR CONTROL OF LEPIDOPTEROUS LARVAE ON GREEN CABBAGE, 2004 John C. Palumbo University of Arizona Department of Entomology Yuma Agricultural Center th 6425 W. 8 St. Yuma, Arizona 85364 Phone: (928) 782-3836 Fax: (928) 782-1940 E-mail: jpalumbo@ag.arizona.edu Cabbage looper (CL): Trichoplusia ni (Hübner) Beet armyworm (BAW): Spodoptera exigua (Hübner) The objective of the study was to evaluate the efficacy of the new compound DPX-E2Y45 relative to standard materials used against lepidopterous larvae on green cabbage under desert growing conditions. Cabbage was direct seeded on 26 Aug 2004 at the Yuma Valley Agricultural Center, Yuma, AZ into double-row beds on 42-inch centers. Stand establishment was achieved using overhead sprinkler irrigation, with furrow irrigation used thereafter. Plots were two beds wide by 40-ft long and bordered by two untreated beds. Four replications of each treatment were arranged in a randomized complete block design. Formulations and rates for each compound are provided in the tables. Sprays were applied on 9 Sep, 18 Sep, 28 Sep and 12 Oct. The applications were made with a CO - operated boom sprayer at 60 psi and 21.5 gpa. A broadcast application was delivered through two TX-18 ConeJet nozzles per bed. An adjuvant, DyneAmic was applied at 0.125% to all treatments. Evaluation of efficacy was based on the number of live larvae per plant. Ten plants per replicate were destructively sampled on each sample date. The sample unit consisted of examination of whole plants for presence of small and large BAW and CL. For BAW, larvae were considered small if <5 mm in length, large if >5mm in length. For CL, larvae were considered small if <10 mm, large if > 10 mm. Treatment means were analyzed using a 1-way ANOVA and means separated by a protected LSD (P = 0.05). BAW and CL pressure was low-moderate compared to past years. In general, treatment differences for BAW and CL control were consistent following each application. BAW efficacy was comparable among the DPX-E2Y45 treatments where significant post-treatment reduction of large larvae was similar for all rates applied compared to the untreated check (Tables 1 and 2). Furthermore, all rates of DPX-E2Y45 reduced large BAW larvae numbers comparable to the industry standards of Success and Proclaim. DPX-E2Y45 also provided good residual control as indicated by significant reductions in small BAW larvae late in the trial. Trends were similar for CL where DPX- E2Y45 treatments provided significant reductions of large CL larvae comparable to the industry standards (Tables 2 and 3). In general, DPX-E2Y45 appeared to provide the most consistent efficacy at higher rates. At one point (28 Sep, 10 DAT #2), residual control was significantly greater when DPX-E2Y45 was applied at the high rate compared to the low rate. Differences in small CL and BAW among the spray treatments and the untreated control following sprays varied throughout the trial and did not reflect a lack of control because many of the small larvae had hatched 2-3 days following each application. These results suggest that DPX-E2Y45 applied at similar rates should provide commercially acceptable control of BAW and CL in desert head lettuce. Table 1. BAW larvae / 10 plants 12 Sep (3 DAT #1) 15 Sep (6 DAT #1) 21 Sep (3 DAT #2) 25 Sep (7 DAT #2) 28 Sep(10 DAT #2) Treatment/ Rate amt Formulation product/acre Small Large Small Large Small Large Small Large Small Large DPX-E2Y45 0.022 lb(AI) 0.3a 0.3b 0.0a 0.7a 0.9a 0.0b 0.3a 0.0a 4.5a 0.0b DPX-E2Y45 0.044 lb(AI) 0.0a 0.0b 1.7a 0.2a 0.0a 0.0b 0.3a 0.3a 0.8a 0.0b DPX-E2Y45 0.066 lb(AI) 0.0a 0.0b 0.2a 0.3a 0.0a 0.0b 0.0a 0.0a 6.2a 0.0b Avaunt 30WDG 3.5 oz 2.0a 0.0b 1.7a 0.7a 0.6a 0.0b 1.8a 0.0a 9.6a 0.9b Success 2SC 5 fl oz 0.5a 0.0b 0.9a 1.0a 0.0a 0.0b 0.6a 0.0a 0.4a 0.8b Proclaim 5WDG 3.2 oz 0.0a 0.0b 0.3a 0.2a 0.3a 0.0b 0.6a 0.0a 1.7a 0.0b Untreated check -- 2.3a 1.8a 1.8a 1.0a 1.5a 3.4a 3.4a 1.5a 9.2a 6.7a Means in a column followed by the same letter are not significantly different based on a protected LSD (P > 0.05). Formulated as a 200 g (AI)/l soluble concentrate. Table 2. BAW larvae / 10 plants 2 Oct (4 DAT #3) 5 Oct (7 DAT #3) 10 Oct (12 DAT #3) 17 Oct (5 DAT #4) Treatment/ Rate amt Formulation product/acre Small Large Small Large Small Large Small Large DPX-E2Y45 0.022 lb(AI) 3.7b 0.0b 11.9a 0.0b 1.8c 0.0b 2.1b 0.0b DPX-E2Y45 0.044 lb(AI) 1.0b 0.0b 3.7a 0.9b 1.0c 0.0b 0.4b 1.3b DPX-E2Y45 0.066 lb(AI) 0.0b 0.0b 17.0a 0.0b 1.0c 0.0b 0.4b 0.0b Avaunt 30WDG 3.5 oz 1.7b 0.8b 12.9a 2.2b 10.5b 3.5b 8.0b 3.3b Success 2SC 5 fl oz 0.5b 0.0b 13.8a 0.0b 6.0bc 0.5b 5.0b 2.5b Proclaim 5WDG 3.2 oz 0.0b 0.0b 22.5a 0.0b 2.0c 0.0b 2.5b 0.0b Untreated check -- 10.0a 10.4a 17.5a 10.9a 20.5a 11.5a 19.2a 14.6a Means in a column followed by the same letter are not significantly different based on a protected LSD (P > 0.05). Formulated as a 200 g (AI)/l soluble concentrate. Table 3. CL larvae / 10 plants 12 Sep (3 DAT #1) 15 Sep (6 DAT #1) 21 Sep (3 DAT #2) 25 Sep (7 DAT #2) 28 Sep(10 DAT #2) Treatment/ Rate amt formulation product/acre Small Large Small Large Small Large Small Large Small Large DPX-E2Y45 0.022 lb(AI) 1.0b 0.0b 2.0a 0.0b 2.2a 0.0b 1.6a 0.0b 5.4a 4.6b DPX-E2Y45 0.044 lb(AI) 1.1b 0.0b 1.4a 0.0b 0.9a 0.0b 0.3a 0.0b 8.3a 2.5bc DPX-E2Y45 0.066 lb(AI) 0.3b 0.0b 0.7a 0.2b 3.7a 0.0b 0.0a 0.0b 6.7a 0.8c Avaunt 30WDG 3.5 oz 0.0b 0.0b 1.2a 0.2b 1.9a 0.3b 0.3a 0.0b 7.1a 5.4b Success 2SC 5 fl oz 0.0b 0.0b 1.1a 0.0b 0.0a 0.0b 0.0a 0.0b 5.0a 0.0c Proclaim 5WDG 3.2 oz 0.0b 0.0b 0.5a 0.0b 0.3a 0.0b 0.3a 0.0b 9.5a 0.8c Untreated check -- 6.3a 2.3a 2.0a 4.3a 1.5a 4.4a 0.9a 5.3a 4.2a 9.2a Means in a column followed by the same letter are not significantly different based on a protected LSD (P > 0.05). Formulated as a 200 g (AI)/l soluble concentrate. Table 4. CL larvae / 10 plants 2 Oct (4 DAT #3) 5 Oct (7 DAT #3) 10 Oct (12 DAT #3) 17 Oct (5 DAT #4) Treatment/ Rate amt Formulation product/acre Small Large Small Large Small Large Small Large DPX-E2Y45 0.022 lb(AI) 6.3a 1.7b 8.1bcd 1.9b 19.5a 7.0b 11.20a 9.2b DPX-E2Y45 0.044 lb(AI) 4.6a 0.0b 6.3d 2.2b 14.5a 6.0b 10.4a 3.8bc DPX-E2Y45 0.066 lb(AI) 11.6a 0.0b 14.4a 0.9b 13.5a 2.5b 12.5a 3.3c Avaunt 30WDG 3.5 oz 2.6a 0.0b 6.6cd 0.0b 18.5a 4.0b 5.0a 0.4c Success 2SC 5 fl oz 7.3a 0.0b 8.8bcd 0.3b 24.0a 4.0b 5.0a 1.3c Proclaim 5WDG 3.2 oz 7.5a 0.0b 12.2ab 0.3b 17.0a 4.5b 12.5a 2.9c Untreated check -- 4.8a 7.8a 10.9abc 10.0a 13.0a 17.0a 20.0a 17.9a Means in a column followed by the same letter are not significantly different based on a protected LSD (P > 0.05). Formulated as a 200 g (AI)/l soluble concentrate.
Arthropod Management Tests – Oxford University Press
Published: Jan 1, 2006
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