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CODLING MOTH CONTROL IN PEARS, 2004

CODLING MOTH CONTROL IN PEARS, 2004 (A33) PEAR: Pyrus communis (L.), 'Bartlett' R. A. Van Steenwyk Department of E.S.P.M. 201 Wellman Hall University of California Berkeley, CA 94720-3112 Phone: (510) 643-5159 Fax: (510) 642-7428 E-mail: bobvanst@nature.berkeley.edu R. M. Nomoto S. K. Zolbrod Codling moth (CM): Cydia pomonella (L.) Pear psylla (PP): Cacopsylla pyricola Förster European red mite (ERM): Panonychus ulmi (Koch) Twospotted spider mite (TSSM): Tetranychus urticae Koch San Jose scale (SJS): Quadraspidiotus perniciosus (Comstock) Western predatory mite (WPM): Galandromus occidentalis (Nesbitt) This trial was designed to evaluate the efficacy of reduced-risk insecticides as possible replacements for conventional insecticides. The trial was conducted on mature 'Bartlett' pear trees in a commercial orchard near Fairfield, CA. Seven treatments were replicated four times in a CRB design. Each replicate consisted of an individual tree. Treatments were applied with a handgun orchard sprayer operating at 250 psi and delivering 200 gpa of finished spray (2.87 gal/tree). Application timings were based on degree-days (DD) (Table 1). DD were calculated with a 20 Mar biofix for the first generation and a 5 Jun biofix for the second generation using a single sine horizontal cutoff model with a lower threshold of 50˚F and an upper threshold of 88˚F. Maximum and minimum air temperatures were obtained from the IMPACT weather station near Cordelia, CA. Control was evaluated at commercial harvest on 21 Jul for CM infestation by inspecting a maximum of 250 fruit per replicate. Control of motile TSSM and ERM, PP nymphs, SJS crawlers and WPM was evaluated weekly from 21 Jun through 12 Jul by sampling 10 exterior and 10 interior leaves per replicate. The leaves were brushed and the contents were counted under magnification (20×). Data were analyzed using ANOVA and Fisher’s Protected LSD mean separation (P ≤ 0.05). This trial was conducted against a very high CM population with over 80% of the fruit infested at harvest in the untreated check (Table 2), and thus should be considered a rigorous test of the experimental materials. All Novaluron treatments (with or without Assail) had CM infestation levels that were not different than the grower standard (Agri-Mek, Imidan, Guthion). It is unknown why the low rate of Diamond had significantly higher infestation than the low rate of Novaluron since both treatments contained the same amount of active ingredient (0.1875 lb AI/acre). Unfortunately, TSSM and ERM populations were very low this year due to unusually cool temperatures and there was no difference among treatments (Table 3). Diamond, Novaluron and Novaluron combined with Assail provided PP control similar to the untreated check and did not stimulate PP to the extent of the grower standard. All experimental treatments suppressed WPM numerically compared to the untreated check, although the two Diamond treatments and the low rate of Novaluron were not statistically different from the check. SJS populations in the Novaluron and Diamond treatments were similar to the untreated check but not as low as the grower standard. Fruit phytotoxicity was observed on the Novaluron treatments. Table 1. Treatment/ Rate No. Formulation lb(AI)/acre appl. Application dates (degree-days from 1st or 2nd biofix) a st st Diamond 7.5WG 0.188 4 31 Mar (106 from 1 biofix), 16 Apr (258 from 1 biofix), 7 Jun nd nd (54 from 2 biofix) and 21 Jun (305 from 2 biofix) a st st Diamond 7.5WG 0.250 4 31 Mar (106 from 1 biofix), 16 Apr (258 from 1 biofix), 7 Jun nd nd (54 from 2 biofix) and 21 Jun (305 from 2 Biofix) a st st Novaluron 0.83EC 0.188 4 31 Mar (106 from 1 biofix), 16 Apr (258 from 1 biofix), 7 Jun nd nd (54 from 2 biofix) and 21 Jun (305 from 2 biofix) a st st Novaluron 0.83EC 0.259 4 31 Mar (106 from 1 biofix), 16 Apr (258 from 1 biofix), 7 Jun nd nd (54 from 2 biofix) and 21 Jun (305 from 2 Biofix) a st nd Novaluron 0.83EC + 0.188 2 16 Apr (258 from 1 biofix) and 18 Jun (253 from 2 biofix) Assail 70WP 0.149 a st nd Novaluron 0.83EC 0.188 2 5 May (540 from 1 biofix) and 2 Jul (506 from 2 biofix) a st Agri-Mek 0.15EC + 0.012 1 16 Apr (258 from 1 biofix) Imidan 70WP 4.9 st nd Guthion 50WP 1.0 2 14 May (656 from 1 biofix) and 18 Jun (253 from 2 biofix) b nd Imidan 70WP 4.2 1 9 Jul (628 from 2 biofix) Untreated check --- --- --- Treatments contained 0.25% v/v Volck Supreme oil by volume. pH was adjusted to < 6 by Tri-Fol. Table 2. Treatment/ Rate No. formulation lb(AI)/acre appl. % CM-infested fruit Diamond 7.5WG 0.188 4 6.4b Diamond 7.5WG 0.250 4 2.6a Novaluron 0.83EC 0.188 4 2.7a Novaluron 0.83EC 0.259 4 2.8a Novaluron 0.83EC + 0.188 2 2.0a Assail 70WP 0.149 Novaluron 0.83EC 0.188 2 Agri-Mek 0.15EC + 0.012 1 1.2a Imidan 70WP 4.9 Guthion 50WP 1.0 2 Imidan 70WP 4.2 1 Untreated check --- --- 80.9c Means followed by the same letter within a column are not significantly different (Fisher's protected LSD, P > 0.05). Data analyzed using an arcsin transformation. Treatments contained 0.25% v/v Volck Supreme oil by volume. pH was adjusted to < 6 by Tri-Fol. Table 3. Insects/20 leaves (season total) Treatment/ Rate No. formulation lb(AI)/acre appl. TSSM ERM PP WPM SJS Diamond 7.5WG 0.188 4 0.3a 0.0a 15.0a 2.9bc 12.8ab Diamond 7.5WG 0.250 4 0.3a 1.0a 19.3a 2.3abc 16.0b Novaluron 0.83EC 0.188 4 0.5a 0.0a 19.5a 1.6abc 8.5ab Novaluron 0.83EC 0.259 4 0.5a 0.0a 20.3a 0.0a 12.0ab Novaluron 0.83EC + 0.188 2 0.0a 0.8a 12.0a 0.6ab 10.0ab Assail 70WP 0.149 Novaluron 0.83EC 0.188 2 Agri-Mek 0.15EC + 0.012 1 0.0a 0.0a 74.8b 0.8ab 3.5a Imidan 70WP 4.9 Guthion 50WP 1.0 2 Imidan 70WP 4.2 1 Untreated check --- --- 0.0a 0.3a 25.0a 3.6c 19.0b Means followed by the same letter within a column are not significantly different (Fisher's protected LSD, P > 0.05). Treatments contained 0.25% v/v Volck Supreme oil by volume. pH was adjusted to < 6 by Tri-Fol. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Arthropod Management Tests Oxford University Press

CODLING MOTH CONTROL IN PEARS, 2004

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Oxford University Press
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2155-9856
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10.1093/amt/30.1.A33
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Abstract

(A33) PEAR: Pyrus communis (L.), 'Bartlett' R. A. Van Steenwyk Department of E.S.P.M. 201 Wellman Hall University of California Berkeley, CA 94720-3112 Phone: (510) 643-5159 Fax: (510) 642-7428 E-mail: bobvanst@nature.berkeley.edu R. M. Nomoto S. K. Zolbrod Codling moth (CM): Cydia pomonella (L.) Pear psylla (PP): Cacopsylla pyricola Förster European red mite (ERM): Panonychus ulmi (Koch) Twospotted spider mite (TSSM): Tetranychus urticae Koch San Jose scale (SJS): Quadraspidiotus perniciosus (Comstock) Western predatory mite (WPM): Galandromus occidentalis (Nesbitt) This trial was designed to evaluate the efficacy of reduced-risk insecticides as possible replacements for conventional insecticides. The trial was conducted on mature 'Bartlett' pear trees in a commercial orchard near Fairfield, CA. Seven treatments were replicated four times in a CRB design. Each replicate consisted of an individual tree. Treatments were applied with a handgun orchard sprayer operating at 250 psi and delivering 200 gpa of finished spray (2.87 gal/tree). Application timings were based on degree-days (DD) (Table 1). DD were calculated with a 20 Mar biofix for the first generation and a 5 Jun biofix for the second generation using a single sine horizontal cutoff model with a lower threshold of 50˚F and an upper threshold of 88˚F. Maximum and minimum air temperatures were obtained from the IMPACT weather station near Cordelia, CA. Control was evaluated at commercial harvest on 21 Jul for CM infestation by inspecting a maximum of 250 fruit per replicate. Control of motile TSSM and ERM, PP nymphs, SJS crawlers and WPM was evaluated weekly from 21 Jun through 12 Jul by sampling 10 exterior and 10 interior leaves per replicate. The leaves were brushed and the contents were counted under magnification (20×). Data were analyzed using ANOVA and Fisher’s Protected LSD mean separation (P ≤ 0.05). This trial was conducted against a very high CM population with over 80% of the fruit infested at harvest in the untreated check (Table 2), and thus should be considered a rigorous test of the experimental materials. All Novaluron treatments (with or without Assail) had CM infestation levels that were not different than the grower standard (Agri-Mek, Imidan, Guthion). It is unknown why the low rate of Diamond had significantly higher infestation than the low rate of Novaluron since both treatments contained the same amount of active ingredient (0.1875 lb AI/acre). Unfortunately, TSSM and ERM populations were very low this year due to unusually cool temperatures and there was no difference among treatments (Table 3). Diamond, Novaluron and Novaluron combined with Assail provided PP control similar to the untreated check and did not stimulate PP to the extent of the grower standard. All experimental treatments suppressed WPM numerically compared to the untreated check, although the two Diamond treatments and the low rate of Novaluron were not statistically different from the check. SJS populations in the Novaluron and Diamond treatments were similar to the untreated check but not as low as the grower standard. Fruit phytotoxicity was observed on the Novaluron treatments. Table 1. Treatment/ Rate No. Formulation lb(AI)/acre appl. Application dates (degree-days from 1st or 2nd biofix) a st st Diamond 7.5WG 0.188 4 31 Mar (106 from 1 biofix), 16 Apr (258 from 1 biofix), 7 Jun nd nd (54 from 2 biofix) and 21 Jun (305 from 2 biofix) a st st Diamond 7.5WG 0.250 4 31 Mar (106 from 1 biofix), 16 Apr (258 from 1 biofix), 7 Jun nd nd (54 from 2 biofix) and 21 Jun (305 from 2 Biofix) a st st Novaluron 0.83EC 0.188 4 31 Mar (106 from 1 biofix), 16 Apr (258 from 1 biofix), 7 Jun nd nd (54 from 2 biofix) and 21 Jun (305 from 2 biofix) a st st Novaluron 0.83EC 0.259 4 31 Mar (106 from 1 biofix), 16 Apr (258 from 1 biofix), 7 Jun nd nd (54 from 2 biofix) and 21 Jun (305 from 2 Biofix) a st nd Novaluron 0.83EC + 0.188 2 16 Apr (258 from 1 biofix) and 18 Jun (253 from 2 biofix) Assail 70WP 0.149 a st nd Novaluron 0.83EC 0.188 2 5 May (540 from 1 biofix) and 2 Jul (506 from 2 biofix) a st Agri-Mek 0.15EC + 0.012 1 16 Apr (258 from 1 biofix) Imidan 70WP 4.9 st nd Guthion 50WP 1.0 2 14 May (656 from 1 biofix) and 18 Jun (253 from 2 biofix) b nd Imidan 70WP 4.2 1 9 Jul (628 from 2 biofix) Untreated check --- --- --- Treatments contained 0.25% v/v Volck Supreme oil by volume. pH was adjusted to < 6 by Tri-Fol. Table 2. Treatment/ Rate No. formulation lb(AI)/acre appl. % CM-infested fruit Diamond 7.5WG 0.188 4 6.4b Diamond 7.5WG 0.250 4 2.6a Novaluron 0.83EC 0.188 4 2.7a Novaluron 0.83EC 0.259 4 2.8a Novaluron 0.83EC + 0.188 2 2.0a Assail 70WP 0.149 Novaluron 0.83EC 0.188 2 Agri-Mek 0.15EC + 0.012 1 1.2a Imidan 70WP 4.9 Guthion 50WP 1.0 2 Imidan 70WP 4.2 1 Untreated check --- --- 80.9c Means followed by the same letter within a column are not significantly different (Fisher's protected LSD, P > 0.05). Data analyzed using an arcsin transformation. Treatments contained 0.25% v/v Volck Supreme oil by volume. pH was adjusted to < 6 by Tri-Fol. Table 3. Insects/20 leaves (season total) Treatment/ Rate No. formulation lb(AI)/acre appl. TSSM ERM PP WPM SJS Diamond 7.5WG 0.188 4 0.3a 0.0a 15.0a 2.9bc 12.8ab Diamond 7.5WG 0.250 4 0.3a 1.0a 19.3a 2.3abc 16.0b Novaluron 0.83EC 0.188 4 0.5a 0.0a 19.5a 1.6abc 8.5ab Novaluron 0.83EC 0.259 4 0.5a 0.0a 20.3a 0.0a 12.0ab Novaluron 0.83EC + 0.188 2 0.0a 0.8a 12.0a 0.6ab 10.0ab Assail 70WP 0.149 Novaluron 0.83EC 0.188 2 Agri-Mek 0.15EC + 0.012 1 0.0a 0.0a 74.8b 0.8ab 3.5a Imidan 70WP 4.9 Guthion 50WP 1.0 2 Imidan 70WP 4.2 1 Untreated check --- --- 0.0a 0.3a 25.0a 3.6c 19.0b Means followed by the same letter within a column are not significantly different (Fisher's protected LSD, P > 0.05). Treatments contained 0.25% v/v Volck Supreme oil by volume. pH was adjusted to < 6 by Tri-Fol.

Journal

Arthropod Management TestsOxford University Press

Published: Jan 1, 2005

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