Arthropod Management Tests 2013, Vol. 38 doi: 10.4182/amt.2013.E57 (E57) Sweet Corn: Zea mays, ‘Symmetry’ EVALUATION OF FOLIAR INSECTICIDES FOR THE CONTROL OF LEPIDOPTERAN LARVAE IN SWEET CORN IN VIRGINIA- 2012 Thomas P. Kuhar Department of Entomology Virginia Tech 216 Price Hall Blacksburg, VA 24061-0319 Phone: (540)231-6129 E-mail: email@example.com Hélène Doughty E-mail: firstname.lastname@example.org James Jenrette Corn earworm (CEW): Helicoverpa zea (Boddie) European corn borer (ECB): Ostrinia nubilalis (Hübner) The objective of this experiment was to assess the efficacy of foliar insecticides for the control of CEW and ECB in sweet corn. The trial consisted of 9 treatments arranged in a RCB design with four replicates. ‘Symmetry’ sweet corn was planted on 11 Jun at the Virginia Tech Eastern Shore Agricultural Research and Extension Center in Painter, VA. Plots were 1 row wide and 20 ft (6.1 m) long with no guard rows. Rows were planted on a 3 ft row center (0.9 m) in a 4 tier field design, 6 ft (1.8 m) alleys between tiers. Foliar treatments were applied on 3, 6, 8, 10, 13, 15, and 17 Aug at 38 gpa with a 1-nozzle boom equipped with D3 spray tips and 45 cores and powered by a CO backpack sprayer at 40psi. On 21 Aug, 30 ears were collected from each plot and examined for lepidopteran larvae and feeding damage recorded as unmarketable or tip damage only. All data were analyzed using ANOVA. Proportion data were arcsine square root transformed prior to analysis. Means were separated using Fisher’s LSD at the 0.05 level of significance. Lepidopteran pressure was moderately high with 70.8% of ears damaged in the untreated check. All insecticide treatments except Vydate L had significantly fewer damaged ears and fewer lepidopteran larvae than the untreated check. No signs of phytotoxicity were observed. This research was supported by grants from FMC Corporation, Bayer CropScience, Syngenta Crop Protection and DuPont Crop Protection. 1 Arthropod Management Tests 2013, Vol. 38 doi: 10.4182/amt.2013.E57 Table 1. % of damaged ears Mean no. larvae/30 ears tip Total Treatment/ Rate – amt damage total lepidopteran formulation product / acre unmarketable only damage CEW ECB larvae Untreated Check 50.8a 20.0bcd 70.8a 16.0b 8.5a 24.5a Hero fb Hero fb 6.4 fb 6.4 fb 6.7cd 5.0d 11.7d 0.5d 0.0b 0.5c Hero fb Mustang Max + 6.4 fb 4 + 16 Lannate LV fb Hero + fb 6.4 + 16 fb Lannate LV fb Mustang 4 + 16 fb 4 + 16 Max + Lannate LV fb Mustang Max + Lannate LV Hero fb Hero fb Mustang 6.4 fb 6.4 fb 4 7.5c 12.5cd 20.0cd 1.3d 0.3b 1.5c Max fb Mustang Max + fb 4 + 16 fb 4 + Lannate LV fb Mustang 16 fb 6.4 + Max + Lannate LV fb 16 fb 6.4 + 16 Hero + Lannate LV fb Hero + Lannate LV Hero fb Hero fb Hero fb 6.4 fb 6.4 fb 2.5cd 10.8cd 13.3d 1.5d 0.0b 1.5c Mustang Max fb Hero fb 6.4 fb 4 fb 6.4 Mustang Max fb Mustang Max fb 4 fb 4 Baythroid XL 2.8 2.5cd 13.3cd 15.8cd 1.5d 0.3b 1.8c Leverage 360 2.8 1.7cd 21.7abc 23.3c 3.0d 0.5b 3.5bc Besiege 9 0.0d 5.0d 5.0e 0.3d 0.0b 0.3c Lannate LV 24 7.5c 34.2ab 41.7b 7.0c 0.5b 7.5b Vydate L 32 22.5b 41.7a 64.2a 23.0a 3.3b 26.3a All data were analyzed using ANOVA. Means were separated using Fisher’s LSD at the 0.05 level of significance. Means followed by the same letter within a column are not significantly different (P>0.05).
Arthropod Management Tests – Oxford University Press
Published: Jan 1, 2013