Control of San Jose Scale in Apple, 2018
John C. Wise, Celeste E Wheeler, Anthony H. VanWoerkom, Larry J. Gut · Arthropod management tests · 2020
The objective of this study was to evaluate the efficacy of several insecticide rates and timings against San Jose scale (SJS) on apple. Two-tree plots were established in a 31-yr-old ‘Red Chief’ apple planting (row spacing 20 × 18 ft) located at the Trevor Nichols Research Center in Fennville MI (Brown Block). There were four replicates per treatment in an RCB design. Test materials were applied with an FMC 1029 tractor-mounted airblast sprayer calibrated to deliver 100 gpa at 2.5 mph. Rates and timings of test materials are as outlined in Table 1 below. In addition, the following foliar maintenance applications were made; Asana, Aprovia, Battallion, Centaur, Inspire Super, Lannate, and Manzate Pro. Glyphosate was banded below the trees for weed control. Means followed by same letter do not significantly differ (P ≤ 0.05, Tukey’s HSD). ANOVA performed on square-root transformed data; data presented are actual counts. A = 10 May (Pink), B = 31 May (Petal Fall), C = 5 Jun (CM Bio + 250DD), D = 3 Jul (1st Gen Crawler Stage), E = 10 Jul (D + 7 days), F = 2 Aug (2nd Gen Crawler Stage). Means followed by same letter do not significantly differ (P ≤ 0.05, Tukey’s HSD). ANOVA performed on square-root transformed data; data presented are actual counts. A = 10 May (Pink), B = 31 May (Petal Fall), C = 5 Jun (CM Bio + 250DD), D = 3 Jul (1st Gen Crawler Stage), E = 10 Jul (D + 7 days), F = 2 Aug (2nd Gen Crawler Stage). A field evaluation consisting of 50 randomly selected fruit per plot was made on 12 Sep. The number of fruit that had scale damage was counted as well as the number of SJS per fruit. Results are shown as the percentage of SJS damaged fruit and mean number of scales per fruit (Table 1). All data were analyzed using ANOVA and means separation by Tukey’s HSD at P < 0.05. ANOVA was run on transformed data, while actual counts are presented. Silmatrix, Sivanto Prime, Sivanto HL, Sivanto / Movento, and X-8064-18 treatments all significantly reduced the incidence of SJS compared to the untreated check, with Sivanto treatments providing the best overall control (Table 1).1