journal article
Open Access Collection
Acaricidal Control of Twospotted Spider Mites in Peanut, 2016
Gay, William H.;Abney, Mark R.
2017 Arthropod Management Tests
doi: 10.1093/amt/tsx080
TwoSpotted Spider Mite (TSSM): Tetranychus urticae (Koch) Peanut (groundnut) | Arachis hypogaea twospotted spider mite | Tetranychus urticae The twospotted spider mite (TSSM) is an important peanut pest due to feeding damage that can result in plant stress and reduced yield especially in hot, dry conditions. A trial was conducted to evaluate efficacy of miticides on TSSM eggs and crawlers in peanut. This trial was conducted from 17 to 31 Aug in Wilcox County, GA, in a nonirrigated, commercial peanut field that experienced moderate to severe drought stress from Jun until harvest. An RCB split plot design was used to evaluate the main plot factor of miticide and the subplot factor of surfactant. Main plots were 8-row wide and 25-ft long and were replicated four times on single row peanuts seeded at a rate of approximately 7 seed per ft with 36 inch between row spacing. Treatments were applied on 18 Aug using a CO2 pressurized backpack sprayer with a 6-ft spray width operating at 4.2 mph and 35 psi with four nozzles (Conejet TXVS 26) delivering 20 gpa. TSSM populations were sampled by collecting 10 quadrifoliate leaves at random from each plot on each sample date. A single leaflet from the same position on each leaf was removed, and eggs and crawlers on 50% of the lower surface of each leaflet were counted using a dissecting microscope. Mites were sampled 1 day before application and 1, 4, 7, and 13 days after application. All data were collected from the two middle rows of each plot. All data were subjected to ANOVA for treatment effects. Means were separated using Fisher’s LSD (P ≤ 0.05) and are presented in Table 1. Use of nonionic surfactant with Agri Mek resulted in significantly fewer TSSM crawlers 7 and 13 DAT, and fewer TSSM eggs 13 DAT compared to Agri Mek alone. The addition of a nonionic surfactant to all other treatments did not affect populations of TSSM eggs and crawlers when compared to the miticide treatments alone. Portal + NIS significantly reduced TSSM crawlers 4 DAT compared to all other treatments except Portal alone, and Comite II +Bifenture. Comite II + NIS, Comite II + Bifenture, Comite II + Bifenture + NIS, Portal, Portal +NIS, and Agri Mek + NIS significantly reduced TSSM eggs and crawlers at 13 DAT compared to the check, Bifenture, and Bifenture + NIS. Bifenture did not cause a significant reduction of TSSM eggs or crawlers compared to the check. Comite II + Bifenture did not reduce TSSM populations when compared to the use of Comite II alone. Table 1 Twospotted spider mites/leaf area sampled 19-Aug 22-Aug 25-Aug 31-Aug Treatment/formulation Rate amt/acre 1 DAT 4 DAT 7 DAT 13 DAT — Crawlers Eggs Crawlers Eggs Crawlers Eggs Crawlers Eggs Check — 86.7a 362.0a 59.2a 341.0ab 105.2a 222.6a 279.0a 179.8a Comite II EC 36 oz 62.2a 365.8a 10.4bcd 10.0b 1.1b 8.0b 4.9c 24.4ab Comite II EC + 36 oz 84.6a 545.0a 9.2bcd 38.1ab 5.4b 32.3ab 1.3c 5.8b NIS SL 1% v/v Comite II EC + 36 oz 50.5a 306.5a 5.7cde 12.3b 1.8b 10.7b 1.7c 2.5b Bifenture EC 6 oz Comite II EC + 36 oz 60.4a 471.8a 17.7abc 46.8ab 2.7b 26.9ab 4.9c 15.3b Bifenture EC + 6 oz NIS SL 1% v/v Bifenture EC 6 oz 125.7a 405.0a 44.1ab 473.3a 162.8a 384.4a 127.1ab 205.7a Bifenture EC + 6 oz 73.7a 341.8a 38.7ab 350.7ab 145.4a 379.9a 110.8ab 183.7a NIS SL 1% v/v Agri Mek EC 3.5 oz 75.3a 296.8a 41.5ab 31.1ab 48.3a 78.6ab 36.0b 141.4a Agri Mek EC + 3.5 oz 62.9a 531.0a 15.6a-d 30.7ab 4.1b 18.9ab 0.2c 1.5b NIS SL 1% v/v Portal EC 32 oz 37.4a 292.5a 2.8de 32.5ab 1.6b 41.0ab 4.6c 11.7b Portal EC + 32 oz 33.4a 225.0a 1.0e 19.6ab 2.0b 26.4ab 3.1c 6.9b NIS SL 1% v/v Twospotted spider mites/leaf area sampled 19-Aug 22-Aug 25-Aug 31-Aug Treatment/formulation Rate amt/acre 1 DAT 4 DAT 7 DAT 13 DAT — Crawlers Eggs Crawlers Eggs Crawlers Eggs Crawlers Eggs Check — 86.7a 362.0a 59.2a 341.0ab 105.2a 222.6a 279.0a 179.8a Comite II EC 36 oz 62.2a 365.8a 10.4bcd 10.0b 1.1b 8.0b 4.9c 24.4ab Comite II EC + 36 oz 84.6a 545.0a 9.2bcd 38.1ab 5.4b 32.3ab 1.3c 5.8b NIS SL 1% v/v Comite II EC + 36 oz 50.5a 306.5a 5.7cde 12.3b 1.8b 10.7b 1.7c 2.5b Bifenture EC 6 oz Comite II EC + 36 oz 60.4a 471.8a 17.7abc 46.8ab 2.7b 26.9ab 4.9c 15.3b Bifenture EC + 6 oz NIS SL 1% v/v Bifenture EC 6 oz 125.7a 405.0a 44.1ab 473.3a 162.8a 384.4a 127.1ab 205.7a Bifenture EC + 6 oz 73.7a 341.8a 38.7ab 350.7ab 145.4a 379.9a 110.8ab 183.7a NIS SL 1% v/v Agri Mek EC 3.5 oz 75.3a 296.8a 41.5ab 31.1ab 48.3a 78.6ab 36.0b 141.4a Agri Mek EC + 3.5 oz 62.9a 531.0a 15.6a-d 30.7ab 4.1b 18.9ab 0.2c 1.5b NIS SL 1% v/v Portal EC 32 oz 37.4a 292.5a 2.8de 32.5ab 1.6b 41.0ab 4.6c 11.7b Portal EC + 32 oz 33.4a 225.0a 1.0e 19.6ab 2.0b 26.4ab 3.1c 6.9b NIS SL 1% v/v Means in a column followed by the same letter are not significantly different (P > 0.05, Fisher’s LSD). Table 1 Twospotted spider mites/leaf area sampled 19-Aug 22-Aug 25-Aug 31-Aug Treatment/formulation Rate amt/acre 1 DAT 4 DAT 7 DAT 13 DAT — Crawlers Eggs Crawlers Eggs Crawlers Eggs Crawlers Eggs Check — 86.7a 362.0a 59.2a 341.0ab 105.2a 222.6a 279.0a 179.8a Comite II EC 36 oz 62.2a 365.8a 10.4bcd 10.0b 1.1b 8.0b 4.9c 24.4ab Comite II EC + 36 oz 84.6a 545.0a 9.2bcd 38.1ab 5.4b 32.3ab 1.3c 5.8b NIS SL 1% v/v Comite II EC + 36 oz 50.5a 306.5a 5.7cde 12.3b 1.8b 10.7b 1.7c 2.5b Bifenture EC 6 oz Comite II EC + 36 oz 60.4a 471.8a 17.7abc 46.8ab 2.7b 26.9ab 4.9c 15.3b Bifenture EC + 6 oz NIS SL 1% v/v Bifenture EC 6 oz 125.7a 405.0a 44.1ab 473.3a 162.8a 384.4a 127.1ab 205.7a Bifenture EC + 6 oz 73.7a 341.8a 38.7ab 350.7ab 145.4a 379.9a 110.8ab 183.7a NIS SL 1% v/v Agri Mek EC 3.5 oz 75.3a 296.8a 41.5ab 31.1ab 48.3a 78.6ab 36.0b 141.4a Agri Mek EC + 3.5 oz 62.9a 531.0a 15.6a-d 30.7ab 4.1b 18.9ab 0.2c 1.5b NIS SL 1% v/v Portal EC 32 oz 37.4a 292.5a 2.8de 32.5ab 1.6b 41.0ab 4.6c 11.7b Portal EC + 32 oz 33.4a 225.0a 1.0e 19.6ab 2.0b 26.4ab 3.1c 6.9b NIS SL 1% v/v Twospotted spider mites/leaf area sampled 19-Aug 22-Aug 25-Aug 31-Aug Treatment/formulation Rate amt/acre 1 DAT 4 DAT 7 DAT 13 DAT — Crawlers Eggs Crawlers Eggs Crawlers Eggs Crawlers Eggs Check — 86.7a 362.0a 59.2a 341.0ab 105.2a 222.6a 279.0a 179.8a Comite II EC 36 oz 62.2a 365.8a 10.4bcd 10.0b 1.1b 8.0b 4.9c 24.4ab Comite II EC + 36 oz 84.6a 545.0a 9.2bcd 38.1ab 5.4b 32.3ab 1.3c 5.8b NIS SL 1% v/v Comite II EC + 36 oz 50.5a 306.5a 5.7cde 12.3b 1.8b 10.7b 1.7c 2.5b Bifenture EC 6 oz Comite II EC + 36 oz 60.4a 471.8a 17.7abc 46.8ab 2.7b 26.9ab 4.9c 15.3b Bifenture EC + 6 oz NIS SL 1% v/v Bifenture EC 6 oz 125.7a 405.0a 44.1ab 473.3a 162.8a 384.4a 127.1ab 205.7a Bifenture EC + 6 oz 73.7a 341.8a 38.7ab 350.7ab 145.4a 379.9a 110.8ab 183.7a NIS SL 1% v/v Agri Mek EC 3.5 oz 75.3a 296.8a 41.5ab 31.1ab 48.3a 78.6ab 36.0b 141.4a Agri Mek EC + 3.5 oz 62.9a 531.0a 15.6a-d 30.7ab 4.1b 18.9ab 0.2c 1.5b NIS SL 1% v/v Portal EC 32 oz 37.4a 292.5a 2.8de 32.5ab 1.6b 41.0ab 4.6c 11.7b Portal EC + 32 oz 33.4a 225.0a 1.0e 19.6ab 2.0b 26.4ab 3.1c 6.9b NIS SL 1% v/v Means in a column followed by the same letter are not significantly different (P > 0.05, Fisher’s LSD). © The Author 2017. 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