(F37) COTTON: Gossypium hirsutum L., ‘Stoneville 4892 BR’ EVALUATION OF NEONICOTONOIDS AGAINST COTTON APHID, 2004 P. L. Bommireddy LSU Agricultural Center Department of Entomology 402 Life Sciences Bldg. Baton Rouge, LA 70803 Phone: (225) 578-1839 Fax: (225) 578-1643 E-mail:
[email protected] R. Gable, K. Tindall, and B. R. Leonard LSU Agricultural Center Macon Ridge Research Station 212A Macon Ridge Rd. Winnsboro, LA 71295 Cotton aphid: Aphis gossypii Glover Selected insecticides were evaluated for control of cotton aphid on ‘Stoneville 4892BR’ cotton at the Macon Ridge Research Station (Franklin Parish). Cotton was planted on 7 May in a Gigger-Gilbert silt loam soil. Plots consisted of four rows (centered on 40-inches) × 50 ft. Treatments were arranged in a RCB design with four replications. Insecticides were applied with a tractor-mounted boom and compressed air system calibrated to deliver 10 gpa through Teejet 8001 flat fan nozzles (2 per row) at 30 psi on 18 Jun. Prior to treatment, 30 plant terminals infested with cotton aphids were marked with a plastic tag. Insecticide efficacy was measured by selecting 10 plant terminals per plot at 3 and 6 DAT. The total number of aphids per plot was determined using whole plant washing procedures. Data were subjected to ANOVA and means separated according to DMRT (P ≤ 0.05). No rainfall occurred during the field trial. All insecticides significantly reduced the number of aphids compared to non-treated plots both at 3 and 6 DAT. The higher rates of Intruder, Bidrin, Trimax, and Centric did not significantly out-perform the lower rates. Plots treated with Intruder and Centric generally had the fewest aphids at 3 and 6 DAT. No phytotoxicity was observed from these insecticide treatments.
No. aphids/10 plant terminals Treatment/ formulation F1785 50DF Intruder 70WP Intruder 70WP Bidrin 8E Bidrin 8E Trimax 4SC Trimax 4SC Centric 40WP Centric 40WP Untreated check P>F
Rate lb (AI)/acre
3 DAT
0.063 0.047 0.024 0.50 0.25 0.047 0.024 0.047 0.024 ---
33.0b 17.5b 5.0b 124.8b 167.3b 61.5b 55.3b 10.5b 21.8b 645.8a
20.0b 8.5b 12.0b 16.3b 26.0b 30.0b 27.3b 8.8b 15.5b 262.8a
