Arthropod Management Tests 2013, Vol. 38 doi: 10.4182/amt.2013.A1 (A1) APPLE: Malus domestica Borkhausen, ‘Delicious’ Elizabeth H. Beers Tree Fruit Research & Extension Center 1100 N. Western Ave. Wenatchee, WA 98801 Phone: 509-663-8181 ext 234 Fax: 509-662-8714 E-mail: email@example.com Bruce M. Greenfield E-mail: firstname.lastname@example.org Woolly apple aphid (WAA): Eriosoma lanigerum (Hausmann) This test was conducted in a 32-yr-old block of ‘Oregon Spur’ and ‘Red Spur Delicious’ with ‘Golden Delicious’ pollenizers at the Tree Fruit Research and Extension Center Columbia View Farm near Orondo, WA. Plots consisted of two trees in a single row. Plots were separated by untreated buffer rows, and a minimum of two untreated trees within rows. The treatments consisted of applications of various pesticides and rates targeting woolly apple aphid at two timings: petal fall (PF) (8 May, with a second application 2 wk later on 22 May); WAA threshold (10 colonies/min) (3 July), with or without second application 14 days later (16 July). Several of the treatments had been applied to the same trees in previous years to examine carryover effects. These treatments included Trt. 2 (Ultor yr 2), Trt. 3 (Ultor yr 3), and Trt. 8 (Closer yr 2) (Table 1). Applications were made with an airblast sprayer calibrated to deliver 100 gpa. WAA populations were assessed by counting the number of visible aerial colonies in a 1-min search per plot. Counts were made weekly or biweekly from early May through early November. The experimental design was a randomized complete block design with 10 treatments and 4 replicates. Data were analyzed with analysis of variance and treatment means were separated using the Waller-Duncan k- ratio t-test. Aphid densities were moderate during May and early June, increasing to a first (summer) peak about the first of July (Table 2). Low to moderate populations persisted throughout the summer, and densities in all treatments increased in the fall to a second peak in early November. When seasonal mean densities were compared, only mean for the Diazinon treatment was significantly lower than the highest treatment (Ultor+Admire). Poor separation of treatments was largely due to the effects of the second (higher) fall population peak, where none of the treatments had an effect. Secondary analyses were performed to separate control of the early vs late season aphid populations, and control of PF vs threshold treatments (Table 3). Ultor+oil (Yr1, Yr2, and Yr3) essentially eliminated the summer peak, and kept populations low until early September. All of the PF-applied treatments had mean aphid densities that were lower than the check. Comparison of the threshold treatments indicated only Diazinon significantly reduced aphid densities relative to the check. However, the Closer treatments were not significantly different than the Diazinon treatment. The essentially prophylactic nature of the PF Ultor treatments gave the overall lowest seasonal aphid densities. This research was supported in part by industry gift(s) of pesticides and/or research funding. 1 Arthropod Management Tests 2013, Vol. 38 doi: 10.4182/amt.2013.A1 Table 1 Rate/acre or Application Carryover Trt. # Pesticide conc. N appl. Timing dates effect 1 Ultor 1.25L 14 fl oz 2 PF, +14 days 8, 22 May Year 1 + EXIT oil 0.25 % v/v 2 Ultor 1.25L 14 fl oz 2 PF, +14 days 8, 22 May Year 2 + EXIT oil 1 % v/v 3 Ultor 1.25L 14 fl oz 2 PF, +14 days 8, 22 May Year 3 + EXIT oil 1 % v/v 4 Ultor 1.25L 14 fl oz 2 Threshold, +14 days 3, 16 July + Admire Pro 7 fl oz + Oil 1 % v/v 5 BYI-2960 200SC 7 fl oz 2 Threshold, +14 days 3, 16 July + Oil 1 % v/v 6 Closer 240 g AI/liter 3 fl oz 2 Threshold, +14 days 3, 16 July + EXIT oil 0.25 % v/v 7 Closer 240 g AI/liter 4.5 fl oz 2 Threshold, +14 days 3, 16 July Year 1 + EXIT oil 0.25 % v/v 8 Closer 240 g AI/liter 4.5 fl oz 1 Threshold 3 July Year 2 + EXIT oil 0.25 % v/v 9 Diazinon 50W 4 lb 1 Threshold 3 July 10 Check Table 2 WAA colonies/1 min search Treatment 8-May 11-May 25-May 31-May 9-Jun 15-Jun 22-Jun 29-Jun 6-Jul 1.Ultor+oil Yr1 2.50a 2.25ab 1.25b 0.00d 0.75bc 1.50bc 1.00bc 1.50cd 1.50cd 2.Ultor+oil Yr2 4.50a 2.50ab 0.00b 0.25d 0.00c 0.00c 0.00c 0.00d 0.25d 3.Ultor+oil Yr3 3.00a 0.25b 0.00b 0.75cd 0.75bc 0.00c 0.00c 0.25d 0.25d 4.Ultor+Admire 5.00a 6.00a 10.50a 7.75ab 4.75abc 7.25a 15.00a 28.50a 26.75a 5.BYI-2960 2.50a 2.75ab 2.25b 4.25bc 7.25ab 7.75a 12.00a 14.50bc 22.50ab 6.Closer 3.0 TH,+14 3.50a 5.00ab 2.75b 3.25cd 2.25abc 8.75a 11.25a 18.25ab 18.75ab 7.Closer 4.5 TH,+14 4.75a 5.25ab 3.50b 8.00a 4.25abc 7.75a 10.50a 18.50ab 21.50ab 8.Closer 4.5 TH Yr2 6.00a 5.50ab 4.00b 3.25cd 6.00abc 10.25a 14.00a 24.75ab 25.75ab 9.Diazinon 2.75a 1.25ab 3.25b 1.50cd 5.75abc 5.75ab 9.00abc 12.75bcd 13.25bc 10.Check 4.75a 6.25a 4.00b 8.00a 8.50a 9.75a 9.75ab 24.00ab 29.00a WAA colonies/1 min search Treatment 11-Jul 20-Jul 27-Jul 2-Aug 9-Aug 17-Aug 24-Aug 7-Sep 17-Sep 1.Ultor+oil Yr1 2.00c 1.50ab 0.00b 2.50c 1.50b 2.75a 5.75a 5.75b 16.00a 2.Ultor+oil Yr2 0.00c 0.25b 0.00b 2.00c 0.00b 2.50a 3.25a 4.50b 17.00a 3.Ultor+oil Yr3 1.25c 2.25ab 0.25b 3.50abc 1.25b 3.50a 4.25a 7.50ab 21.25a 4.Ultor+Admire 18.00a 5.75ab 3.25ab 9.50ab 6.75a 4.25a 11.75a 16.75a 30.50a 5.BYI-2960 9.25abc 2.00ab 0.75ab 4.25abc 2.75b 4.75a 9.25a 8.75ab 22.00a 6.Closer 3.0 TH,+14 11.25abc 2.50ab 0.50ab 3.00bc 0.50b 1.75a 3.25a 5.50b 24.00a 7.Closer 4.5 TH,+14 10.25abc 1.50ab 0.50ab 4.00abc 0.25b 3.50a 7.50a 3.00b 14.00a 8.Closer 4.5 TH Yr2 10.75abc 6.25ab 1.50ab 2.25c 2.00b 2.75a 5.75a 4.75b 11.50a 9.Diazinon 5.00bc 1.25ab 0.50b 2.50c 0.00b 1.50a 4.75a 3.50b 12.00a 10.Check 15.00ab 11.00b 3.75a 10.25a 3.25b 4.75a 9.75a 11.00ab 20.25a WAA colonies/1 min search Treatment 1-Oct 8-Oct 16-Oct 23-Oct 30-Oct 6-Nov 13-Nov 1.Ultor+oil Yr1 35.25a 38.00a 28.75ab 54.25a 38.50a 44.25a 63.00a 2.Ultor+oil Yr2 30.75a 31.50a 24.00b 44.50a 56.25a 51.50a 63.00a 3.Ultor+oil Yr3 41.50a 37.00a 28.00ab 33.25a 39.50a 46.75a 61.75a 4.Ultor+Admire 59.00a 66.25a 61.25a 80.50a 55.25a 71.75a 102.50a 5.BYI-2960 38.00a 42.00a 26.50b 56.25a 47.25a 52.00a 83.75a 6.Closer 3.0 TH,+14 25.50a 22.50a 14.25b 24.00a 17.75a 30.25a 36.00a 7.Closer 4.5 TH,+14 34.50a 28.00a 23.00b 34.00a 25.00a 44.00a 64.25a 8.Closer 4.5 TH Yr2 21.25a 23.50a 17.00b 30.00a 22.50a 32.75a 40.25a 9.Diazinon 26.75a 30.00a 18.00b 30.75a 22.00a 18.75a 34.25a 10.Check 41.25a 48.75a 38.25ab 39.75a 43.50a 47.25a 74.25a Means followed by the same letters are not significantly different (P > 0.05) according to the Waller-Duncan k-ratio t-test. Applications made at petal fall, 8 May; PF+14, 22 May; WAA threshold, 3 July; Threshold+14, 16 July. 2 Arthropod Management Tests 2013, Vol. 38 doi: 10.4182/amt.2013.A1 Table 3 WAA colonies/min (seasonal means) May-Sep Treatment May-Nov May-Sep Sep-Nov PF trts only Threshold trts only 1.Ultor+oil Yr1 14.08ab 1.77e 35.97a 1.77b 2.Ultor+oil Yr2 13.54ab 0.97e 35.89a 0.97b 3.Ultor+oil Yr3 13.52ab 1.34e 35.17a 1.34b 4.Ultor+Admire 28.58a 10.67a 60.42a 10.67a 5.BYI-2960 19.41ab 6.80bcd 41.83a 6.80ab 6.Closer 3.0 TH,+14 11.85ab 6.03bcd 22.19a 6.03ab 7.Closer 4.5 TH,+14 15.25ab 6.97bcd 29.97a 6.97ab 8.Closer 4.5 TH Yr2 13.37ab 8.17abc 22.61a 8.17ab 9.Diazinon 10.67b 4.42de 21.78a 4.42b 10.Check 21.04ab 10.11ab 40.47a 10.11a 10.11a Means followed by the same letters are not significantly different (P > 0.05) according to the Waller-Duncan k-ratio t-test. Applications made at petal fall, 8 May; PF+14, 22 May; WAA threshold, 3 July; Threshold+14, 16 July.
Arthropod Management Tests – Oxford University Press
Published: Jan 1, 2013