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(A9) APPLE: Malus domestica Borkhausen, ‘Fuji’, ‘Golden Delicious’, ‘Liberty’, ‘York’ Henry W. Hogmire West Virginia University Tree Fruit Research and Education Center P.O. Box 609 Kearneysville, WV 25430 Phone: (304) 876-6353 Fax: (304) 876-6034 E-mail: email@example.com Tim Winfield Rosy apple aphid (RAA): Dysaphis plantaginea (Passerini) Spirea aphid (SA): Aphis spiraecola Patch Aphid natural enemies (includes adults and larvae of ladybird beetles, minute pirate bug, and larvae of syrphid fly, green lacewing, and aphid midge) Spotted tentiform leafminer (STLM): Phyllonorycter blancardella (F.) Oriental fruit moth (OFM): Grapholita molesta (Busck) Codling moth (CM): Cydia pomonella (L.) Japanese beetle (JB): Popillia japonica Newman Tufted apple bud moth (TABM): Platynota idaeusalis (Walker) Tarnished plant bug (TPB): Lygus lineolaris (Palisot de Beauvois) Plum curculio (PC): Conotrachelus nenuphar (Herbst) European apple sawfly (EAS): Hoplocampa testudinea (Klug) Apple maggot (AM): Rhagoletis pomonella (Walsh) This experiment was conducted in a 3.6-acre block of 12-yr-old trees on M.26 rootstock. The block consisted of two identical 1.8-acre sections equally divided among the four cultivars. Trees measured 10 ft. in height and 10 ft. in width and were planted at a spacing of 8 x 18 ft. Insecticides were applied as complete sprays to both sides of the trees with a Swanson DA500A airblast sprayer, which traveled at 2.6 mph and delivered a spray volume of 100 gpa for all applications, except for Surround which was 200 gpa. Pest control was determined by counting arthropods or injury on 4 single-tree replications per cultivar in each section of the block. Control of RAA was determined by counting the number of colonies per tree. SA control was evaluated by determining the number of infested leaves on each of 10 terminals per tree. Aphid natural enemy incidence was determined on the same 10 terminals used for SA counts. STLM incidence was determined by counting all tissue-feeder mines during a 5 minute period per tree. Control of first generation OFM was determined by counting the number of injured terminals per tree. Up to 100 fruit were examined on each tree to determine injury by CM and OFM. Injured fruit were collected and internal larvae were removed and identified. JB impact was assessed by counting the number of injured leaves per tree. Injury from fruit-feeding insects was determined at harvest by evaluating 50 apples for each single-tree replication that were collected on 26 Aug (‘Liberty’), 7 Sep (‘Golden Delicious’), 6 Oct (‘York’, ‘Fuji’). Pheromone mating disruption dispensers (Isomate-M Rosso, Isomate-C TT and Isomate- M 100) were installed in the upper third of the tree canopy in a uniform pattern throughout the block to achieve the appropriate density per acre. Isomate-M Rosso and Isomate-M 100 dispensers were wrapped loosely around branches, whereas Isomate-C TT dispensers were slipped over an upright branch. Pest control was determined for each cultivar by averaging arthropod incidence or injury found on 4 single- tree replications in each 1.8 acre section of the block (8 replications total). Mean comparisons among cultivars were made with Fisher's Protected LSD at P ≤ 0.05. No RAA colonies were detected on any cultivars, with control provided by JMS Stylet Oil and Aza- Direct (Table 1). SA was most abundant on ‘Golden Delicious’, which was the only cultivar to exceed the threshold of 4 infested leaves/terminal. Aphid natural enemies were abundant on all cultivars. Incidence of STLM mines was very low on all cultivars, with ‘Fuji’ having significantly more than ‘Golden Delicious’ and ‘Liberty’. OFM terminal injury occurred on all cultivars, but was significantly greater on ‘York’ than on ‘Fuji’ and ‘Liberty’ (Table 2). The occurrence of OFM terminal injury was surprising, since Isomate-M Rosso dispensers were installed properly before the beginning of moth flight, and no moths were captured in pheromone traps. The use of Isomate-C TT, Cyd-X and Isomate-M 100 maintained in-season fruit injury from CM & OFM at less than one percent on all cultivars, except for ‘Liberty’ on 28 Jun (1.6%). Incidence of JB-injured leaves was significantly higher on ‘Liberty’ than on all the other cultivars. Harvest fruit injury from CM & OFM was two percent or less and not significantly different among the cultivars (Table 3). OFM was the predominant species of larvae found in injured fruit in both in-season and harvest evaluations. Entrust provided very effective control of TABM, with ‘York’ having a significantly higher level of injury than ‘Golden Delicious’ and ‘Liberty’. Injury from TPB was low and similar on all cultivars, except for ‘Golden Delicious’ which was significantly higher. PC was responsible for most of the fruit injury on all cultivars, with a significantly higher level on ‘Liberty’ than on ‘Fuji’ and ‘York’. This occurred despite two applications of a high rate of Surround, which was timed specifically for PC control at petal fall and 10 days later. A third application probably should have been included. Low levels of injury from EAS and AM were detected, which did not significantly differ among the cultivars. ‘York’ had the highest percentage of clean fruit, which was significantly greater than that of ‘Golden Delicious’ and ‘Liberty’. Table 1. RAA SA infested Natural enemies STLM colonies/tree leaves/terminal /10 terminals mines/5 min Treatment/ Rate Rate formulation amt product/acre lb(AI)/acre Time of application Cultivar 7 Jun 7 Jun 7 Jun 2 Aug JMS Stylet Oil 15.2 liters --- 31 Mar 'Fuji' 0.0a 2.6ab 12.8a 4.8a Isomate-M Rosso 160 disp. --- 5 Apr JMS Stylet Oil 11.4 liters --- 9 Apr 'Golden Delicious' 0.0a 4.4a 9.8a 0.0b Aza-Direct 947 ml 0.02 9 & 14 Apr Isomate-C TT 200 disp. --- 23 Apr 'Liberty' 0.0a 1.9b 5.2a 0.9b Surround WP 50 lb 42.5 4 & 14 May, 15 & 29 Jul Cyd-X 80 ml 0.00009 20 & 28 May 'York' 0.0a 1.6b 4.9a 1.6ab Entrust 80WP 85 g 0.15 3 & 10 Jun, 9 Aug Isomate-M 100 100 disp. --- 7 Jun Means in a given column followed by the same letter are not significantly different (Fisher’s Protected LSD, P ≤ 0.05). Includes ladybird beetle adults and larvae, minute pirate bug, and larvae of syrphid fly, green lacewing, and aphid midge. Table 2. OFM-injured JB injured terminals/tree % CM & OFM fruit injury leaves/tree Treatment/ Rate Rate a b formulation amt product/acre lb(AI)/acre Time of application Cultivar 24 May 28 Jun 26 Jul 20 Aug JMS Stylet Oil 15.2 liters --- 31 Mar 'Fuji' 5.5b 0.3b 0.9a 1.3b Isomate-M Rosso 160 disp. --- 5 Apr JMS Stylet Oil 11.4 l liters --- 9 Apr 'Golden Delicious' 9.4ab 0.5ab 0.8a 1.1b Aza-Direct 947 ml 0.02 9 & 14 Apr Isomate-C TT 200 disp. --- 23 Apr 'Liberty' 5.7b 1.6a 0.5a 4.5a Surround WP 50 lb 42.5 4 & 14 May, 15 & 29 Jul Cyd-X 80 ml 0.00009 20 & 28 May 'York' 12.5a 0.4b 0.1a 1.1b Entrust 80WP 85 g 0.15 3 & 10 Jun, 9 Aug Isomate-M 100 100 disp. --- 7 Jun Means in a given column followed by the same letter are not significantly different (Fisher’s Protected LSD, P > 0.05). Larvae identified as 100% OFM. Larvae identified as 75% OFM; 25% CM. Rating for number of JB injured leaves/tree: 0 = none; 1 = 1-50; 2 = 51-100; 3 = 101-150; 4 = 151-200; 5 > 200. Table 3. % fruit injury by: Treatment/ Rate Rate % formulation amt product/acre lb(AI)/acre Time of application Cultivar CM & OFM TABM TPB PC EAS AM clean fruit JMS Stylet Oil 15.2 liters --- 31 Mar ‘Fuji’ 2.0a 3.5ab 0.5b 22.0bc 2.0a 4.5a 65.5ab Isomate-M Rosso 160 disp. --- 5 Apr JMS Stylet Oil 11.4 liters --- 9 Apr ‘Golden Delicious’ 1.5a 1.5b 8.0a 33.5ab 0.5a 1.5a 57.0b Aza-Direct 947 ml 0.02 9 & 14 Apr Isomate-C TT 200 disp. --- 23 Apr ‘Liberty’ 1.5a 0.5b 1.5b 48.5a 1.0a 0.0a 49.5b Surround WP 50 lb 42.5 4 & 14 May, 15 & 29 Jul Cyd-X 80 ml 0.00009 20 & 28 May ‘York’ 1.0a 7.5a 0.5b 16.0c 0.0a 0.0a 75.0a Entrust 80WP 85 g 0.15 3 & 10 Jun, 9 Aug Isomate-M 100 100 disp. --- 7 Jun Means in a given column followed by the same letter are not significantly different (Fisher’s Protected LSD, P ≤ 0.05). Larvae identified as 87.5% OFM; 12.5% CM.
Arthropod Management Tests – Oxford University Press
Published: Jan 1, 2005
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