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Arthropod Management Tests 2012, Vol. 37 doi: 10.4182/amt.2012.F6 (F6) ALFALFA: Medicago sativa L. ‘CUF-101’ Eric T. Natwick University of California Agriculture and Natural Resources Desert Research and Extension Center 1050 E. Holton Rd. Holtville, CA 92250 Phone: (760) 352-9474 Fax: (760) 352-0846 E-mail: firstname.lastname@example.org Martin I. Lopez E-mail: email@example.com Lygus bug (LB): Lygus spp. Say stink bug (SB): Chlorochroa sayi (Stål) Alfalfa seed chalcid (ASC): Bruchophagus roddi (Gussakovsky) The objective of the study was to evaluate the efficacy of the new and old insecticidal compounds used against adults and nymphs of LB and SB on alfalfa grown for seed production under desert growing conditions. An insecticide efficacy trial was conducted at the UC Desert Research and Extension Center on a stand of CUF-101 alfalfa on beds of 40 inch centers. The experimental design was RCB using 4 replicates with 11 insecticide treatments and an untreated check. Plots were eight beds 35 ft wide by 100 ft long. The insecticide treatments were applied on the dates at the specified rate equivalencies listed in the tables. All insecticide treatments were applied on 16 Jun. The applications were broadcast sprays made with a Lee Spider Spray Trac, tractor mounted spray boom, equipped with 19 nozzles (TJ-60 11003VS) per 35 ft swath, operated at 15 psi, and delivering 23 gpa. Hasten Modified Vegetable Oil (Wilbur- Ellis Company) was applied at 0.25% vol/vol in a tank mixtures with all insecticide treatments. Helena Buffer PS (Helena Chemical Company) was used to buffer the Carzol spray mixture to pH 5.0. Pretreatment insect population evaluations were conducted on 15 Jun or 1-day prior to treatment (1DPT). Post treatment insect populations were evaluated on the following dates and days after treatment (DAT) of 20, 23, 30 Jun, and 7 Jul or 4DAT, 7DAT, 14DAT, and 21DAT, respectively. During each evaluation, ten 180° sweeps per plot were collected with a standard 15-inch diameter sweep net. Sweep net samples were bagged, labeled, and frozen for st rd th th later counting of small LB nymphs (1 through 3 instars), large LB nymphs (4 and 5 instars), LB adults, and SB adults and nymphs. On 18 Jul 2011, mature seed pods were stripped from a few plants at random in each plot, pods were hand-threshed to prevent loss of damaged seed, and 100 random seeds from each plot were examined under a binocular microscope for LB damage, SB damage, ASC damage, chewing insect damage, water damage, green seed and good seed. Treatment means were analyzed using 2- way ANOVA and means separated by a protected LSD (P=0.05). Pre-treatment numbers of small LB nymphs, large LB nymphs and adult LB were similar among treatments and the untreated check (Table 1-3). Only the insecticide treatments Carzol, Belay, Orthene, and Rimon had fewer small LB than the untreated check 4DAT and only the insecticide treatments Dibrom, Carzol, Belay, and Orthene had fewer small LB than the untreated check 7DAT (Table 1). None of the insecticide treatments had fewer small LB nymphs compared to the check 14DAT and 21DAT. Capture had significantly more small LB nymphs than the check and all other insecticide 14DAT and Capture had more small LB nymphs than the check and all other insecticide treatments except Rimon 21DAT. Only the insecticide treatments Carzol and Belay had fewer small LB nymphs than the untreated check for the post treatment average (PTA) and Capture had significantly more small LB nymphs compared to the check for the PTA. Only the insecticide treatments Belay Insecticide had fewer large LB nymphs than the untreated check 4DAT and only the insecticide treatments Dibrom, Carzol, Belay, Orthene and Rimon had fewer large LB nymphs than the untreated check 7DAT (Table 2). None of the insecticide treatments had fewer large LB nymphs compared to the check 14DAT and 21DAT. Only the insecticide treatments Carzol and Belay had fewer large LB nymphs than the untreated check for the PTA. None of the insecticide treatments had significantly fewer LB adults than the check on any of the post treatment sampling dates (Table 3). Only the insecticide treatments Carzol and Belay had significantly fewer LB adults than the untreated check for the PTA. There were no symptoms of phytotoxicity following any of the insecticide treatments. This research was supported funding from the California Alfalfa Seed Production Research board and by industry gifts. 1 Arthropod Management Tests 2012, Vol. 37 doi: 10.4182/amt.2012.F6 Table 1. Small LB nymphs per ten sweeps Treatment/ Oz product/ formulation acre 1DPT 4DAT 7DAT 14DAT 21DAT PTA Check - 4.75a 7.05ab 13.50ab 6.75b 8.25b 8.94b Dibrom 8 7.5EC 20.0 fl 1.75a 3.74abc 5.00cde 8.00b 7.50b 6.19bcd Beleaf 50SG 2.8 dry 5.25a 6.10ab 12.75abc 3.50b 7.50b 7.94bc Assail 70WP 1.7 dry 4.00a 3.90abc 10.75abc 1.00b 4.50b 5.13bcd Stallion 3EC 11.75 fl 5.25a 2.50bc 12.25abc 7.50b 8.25b 8.19bc Carzol92 SP 8.0 dry 2.25a 1.55c 1.25e 2.00b 2.75b 2.06d Steward 1.25EC 11.0 fl 6.75a 4.18abc 13.75a 6.75b 4.75b 7.50bc Belay 50WDG 2.8 fl 5.75a 1.00c 2.50de 4.50b 7.50b 3.94cd Orthene 97S 16.0 dry 5.50a 3.24abc 1.00e 8.50b 9.75b 5.69bcd Rimon 0.83 EC 12.0 fl 5.00a 9.72a 5.75bcde 3.00b 3.00ab 5.44bcd Capture 2EC 5.12 fl 4.50a 9.04a 9.25abcd 22.25a 16.25a 15.06a Lorsban 4E 32.0 fl 5.50a 1.45c 10.00abcd 4.50b 8.50b 6.19bcd Means within columns followed by the same letter are not significantly different (LSD; P=0.05) Log transformed data used for analysis and reverse transformed means shown in table. Table 2. Large LB nymphs per ten sweeps Treatment/ Oz product/ y y y formulation acre 1DPT 4DAT 7DAT 14DAT 21DAT PTA Check - 7.25a 6.87 ab 10.92a 10.25cde 3.25a 7.89ab Dibrom 8 7.5EC 20.0 fl 2.50a 2.76bc 1.59d 19.25ab 5.50a 6.85bc Beleaf 50SG 2.8 dry 6.25a 7.42ab 11.39a 5.75e 4.50a 7.62ab Assail 70WP 1.7 dry 3.25a 3.82bc 9.40ab 8.00de 2.00a 6.25bcd Stallion 3EC 11.75 fl 4.25a 3.05bc 9.26ab 18.75abc 3.00a 8.58ab Carzol 92SP 8.0 dry 4.75a 2.72bc 3.82bcd 5.75e 1.50a 3.73d Steward 1.25EC 11.0 fl 7.75a 3.12bc 7.90abc 17.75abc 0.50a 7.37b Belay 50WDG 2.8 fl 5.00a 1.43c 2.94cd 8.25de 3.25a 4.05cd Orthene 97S 16.0 dry 5.00a 6.00ab 1.99d 16.00abcd 2.00a 6.46bc Rimon 0.83EC 12.0 fl 6.00a 7.29ab 4.18bcd 8.50de 0.00a 5.25bcd Capture 2EC 5.12 fl 5.50a 11.60a 7.97abc 21.75a 5.75a 12.09a Lorsban 4E 32.0 fl 6.00a 4.57abc 6.52abc 12.75bcde 2.75a 6.65bc Means within columns followed by the same letter are not significantly different (LSD; P=0.05) Log transformed data used for analysis and reverse transformed means shown in table. Table 3. LB adults per ten sweeps Treatment/ Oz product/ formulation acre 1DPT 4DAT 7DAT 14DAT 21DAT PTA Check - 18.50a 19.00a 14.25a 27.75bcd 10.25a 17.81ab Dibrom 8 7.5EC 20.0 8.00a 24.50a 7.75a 29.25bc 6.25a 16.94abc Beleaf 50SG 2.8 13.00a 19.25a 10.00a 21.25cd 7.25a 14.44bc Assail 70WP 1.7 16.00a 15.00a 11.00a 26.50bcd 4.00a 14.13bc Stallion 3EC 11.75 11.25a 15.75a 11.25a 31.50bc 4.75a 15.81bc Carzol 92SP 8.0 11.50a 13.25a 9.25a 17.50d 4.75a 11.19c Steward 1.25 EC 11.0 19.00a 16.50a 15.75a 34.75b 8.75a 18.94ab Belay 50WDG 2.8 14.25a 8.50a 7.50a 22.25cd 6.00a 11.06c Orthene 97S 16.0 12.50a 22.75a 12.00a 22.25cd 9.50a 16.63abc Rimon 0.83EC 12.0 15.25a 15.50a 10.50a 29.00bc 4.75a 14.94bc Capture 2EC 5.12 13.25a 15.50a 17.75a 49.00a 8.75a 22.75a Lorsban 4E 32.0 13.2a5 13.25a 12.25a 24.50bcd 7.00 14.25bc Means within columns followed by the same letter are not significantly different (LSD; P=0.05) 2 Arthropod Management Tests 2012, Vol. 37 doi: 10.4182/amt.2012.F6 Table 4. SB adults and nymphs per ten sweeps Treatment/ Oz product/ formulation acre 1DPT 4DAT 7DAT 14DAT 21DAT PTA Check - 0.00 0.00 0.50 1.25 0.75 0.63 Dibrom 8 7.5EC 20.0 fl 0.00 0.50 0.25 0.75 0.75 0.56 Beleaf 50SG 2.8 0.00 0.00 0.00 0.50 1.00 0.38 Assail 70WP 1.7 0.00 0.00 0.50 0.50 3.00 1.00 Stallion 3EC 11.75 0.00 0.25 0.50 0.75 0.25 0.44 Carzol 92SP 8.0 0.00 0.00 0.75 0.00 0.50 0.31 Steward 1.25EC 11.0 0.00 0.75 0.50 1.50 1.50 1.06 Belay 50WDG 2.8 0.00 0.00 0.00 0.00 0.75 0.19 Orthene 97S 16.0 0.00 0.50 0.25 0.75 2.25 0.94 Rimon 0.83EC 12.0 0.00 0.00 0.25 0.25 1.50 0.50 Capture 2EC 5.12 0.00 0.00 0.00 0.25 0.75 0.25 Lorsban 4E 32.0 0.00 0.00 0.00 0.25 1.50 0.44 NS NS NS NS NS NS Table 5. Percentage of seed damaged from LB, SB, ASC and water and percentages of green seed and healthy seed Treatment/ Oz product/ Chewing Water Green Good formulation acre LB SB SC damage damag seed seed Check - 23.50a 3.00a 2.00a 0.75a 0.25a 0.25a 70.25b Dibrom 8 7.5EC 20.0 fl 11.25bc 2.50a 1.00a 0.50a 0.50a 0.50a 83.75a Beleaf 50SG 2.8 dry 10.75c 1.00a 2.00a 0.75a 0.00a 0.25a 85.25a Assail 70WP 1.7 dry 12.25bc 1.25a 0.75 0.25 0.75 0.00 84.75a Stallion 3EC 11.75 fl 17.00b 1.75a 1.75a 0.00a 0.25a 0.00a 79.25a Carzol 92SP 8.0 dry 12.25bc 2.00a 3.00a 0.25a 0.50a 0.25a 81.75a Steward 1.25EC 11.0 fl 16.00bc 1.75a 1.25a 0.50a 0.00a 0.75a 79.75a Belay 50WDG 2.8 fl 11.50bc 2.25a 2.75a 0.50a 1.00a 0.75a 81.25a Orthene 97S 16.0 dry 16.25bc 2.50a 0.75a 0.25a 0.00a 0.00a 80.25a Rimon 0.83EC 12.0 fl 12.50bc 1.00a 0.75a 0.25a 0.00a 0.25a 85.25a Capture 2EC 5.12 fl 12.75bc 1.50a 1.00a 0.75a 0.00a 0.25a 83.75a Lorsban 4E 32.0 fl 14.25bc 1.75a 2.00a 0.25a 0.25a 0.25a 81.25a Means within columns followed by the same letter are not significantly different (LSD; P=0.05)
Arthropod Management Tests – Oxford University Press
Published: Jan 1, 2012
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