(F54) COTTON: Gossypium hursutam L., 'Deltapine 425R' EFFICACY OF ASANA XL IN COMBINATION WITH NEW CHEMISTRY FOR HELIOTHINE CONTROL ON COTTON, 2001 Donald R. Johnson University of Arkansas Cooperative Extension Service 2301 S. University Ave. Box 391 Little Rock, AR 72203 Tel: 501-671-2229 Fax: 501-671-2303 firstname.lastname@example.org Gus M. Lorenz III email@example.com John D. Hopkins firstname.lastname@example.org Jack D. Reaper III email@example.com Kenneth D. Walsh University of Arkansas Cooperative Extension Service P.O. Box 357 2001 HWY 70 East Lonoke, AR 72086 Tel: 501-676-3124 Fax: 501-676-7847 firstname.lastname@example.org Bollworm (BW): Helicoverpa zea (Boddie) Tobacco budworm (TBW): Heliothis virescens (F.) A trial was conducted on the Chuck Hooker Farm in Jefferson County, AR, to evaluate the efficacy of Asana XL in combination with new chemistry for Heliothine control. This farm was located within the boll weevil eradication zone and received programmed sprays of ultra-low volume malathion that virtually eliminated boll weevil pressure and reduced plant bug pressure. A combination of new and traditional chemistry was selected for evaluation. Treatments were arranged in a RCB design with four replications. Plot size was eight 38-inch rows x 50 ft. The trial was planted on 30 Apr with cotton variety Deltapine 425R and was furrow-irrigated as needed. Heliothine population makeup bollworm/tobacco budworm(BW/TBW) was determined by the use of pheromone traps. Treatments were initiated based on estimated peak Heliothine egg lay. Applications were made with a John Deere 6000 hi-cycle sprayer equipped with a compressed air delivery system. The boom was equipped with conejet TXVS-6 nozzles on a 19-inch spacing. Operating pressure was 45 psi with a final spray volume of 8.6 gpa. Treatments were applied as foliar sprays on 11Jul, 18 Jul, and 3 Aug. Insect counts and damage ratings were made on 16 Jul (5 DAT no. 1), 23 Jul (5 DAT no. 2), 7 Aug (4 DAT no. 3). Data were collected by examining 50 squares and 50 terminals at random from the center of each plot for the presence of live larvae and square damage. The center two rows of each plot were machine harvested with a commercial two-row John Deere cotton picker on 25 Oct (178 days after planting) and lint yields were determined based on a 35% gin turnout. Data were processed using Agriculture Research Manager Version 6.0.1. ANOVA was performed and DMRT (P = 0.05) was used to separate means only when AOV Treatment P(F) was significant at the 5% level. Populations of TBW and cotton BW were lower than those observed in 2000. Normally, TBW populations are greater in late Jul through early Aug. While this trend held true in 2001, overall pressure was lower than normal. All treatments observed in this study resulted in fewer damaged squares, total live larvae, and greater lint yield when compared to the untreated check. However, no differences in these parameters were observed between Steward, Tracer, Denim, and S-1812 when used alone or in combination with Asana XL. The addition of Asana XL (0.04 lb (AI)/acre) mixed with a reduced rate of Intrepid (0.10 lb (AI)/acre) did significantly reduce square damage below that observed for the labeled rate of Intrepid (0.15 lb (AI)/acre). Although square damage was suppressed with the tank mix, no difference in live larvae or lint yield was observed. While no differences in total live larvae were observed, Intrepid did have a lower yield than was observed with the Asana XL, Tracer, Denim, S-1812, and Asana + Tracer tank mix. The higher percentage square damage recorded for the Intrepid treatment more than likely caused this yield decrease. Lack of significance among treatments indicates satisfactory performance of Asana XL used in combination with reduced rates of newer insecticides. It is important to note that equal levels of Heliothine control were achieved using labeled rates of all insecticides, including Asana XL, with the exception of Intrepid. Heliothine insect populations, particularly for TBW were lower in 2001 than those observed in previous years. This fact may have contributed to the performance of the Asana XL treatment. Many Heliothine control options currently exist for cotton producers in Arkansas. However, strict insecticide management is vital for preventing resistance in all production areas. Combining new compounds with traditional chemistry has, in this study and others, been an effective method of controlling the Heliothine complex. More importantly, a greater number of options are introduced to the producer while helping to manage insect resistance.
Arthropod Management Tests – Oxford University Press
Published: Jan 1, 2003