Control of Rice Water Weevil With Fipronil Applied Post-Flood in a Dry-Seeded, Delayed Flood Cul-Ture,1996
Abstract The experiment was conducted at the TAMU Agricultural Research and Extension Center at Beaumont and was designed as a RCB with 9 treatments and 4 replications. Each plot was 15 ft X 8 ft and surrounded by a metal barrier to prevent movement of insecticide. On 10 Apr, plots were fertilized with urea at 68 lb nitrogen/acre. On the same day, dry plots were planted by hand with dry seed at 90 lb/acre. Designated plots received fipronil-treated seed which was provided by Rhone-Poulenc Ag Company. Fertilizer and seed were incorporated into the soil (League clay) with a rake. Plots were flush irrigated (temporary flood for 24 h then drain) following incorporation. Rice emerged 19 Apr. From emergence of rice through the soil to application of the permanent flood on 10 May (21 d after rice emergence), plots were flush irrigated as needed. On 30 Apr, plots were treated with Stam 4E and Basagran at 4.0 and 1.0 lb (AI)/acre, respectively. Immediately prior to the permanent flood, plots were fertilized with urea at 51 lb nitrogen/acre. On the same date and before the permanent flood, designated plots were treated with a fipronil spray treatment using a 4 nozzle (tip size 800067, 50 mesh screens), hand-held, spray rig pressurized with CO2 Final spray volume was 34.8 gpa. This treatment was not incorporated. Designated plots were also treated with fipronil, Dimilin 25 WP, and Karate 1EC spray treatments at the rates and specific times after the permanent flood as described in the accompanying table. These treatments were applied as above. Furadan 3G was applied to designated plots at 0.6 lb (AI)/acre 11 d after the permanent flood with a hand-held shaker jar. Plots were fertilized with urea at 51 lb nitrogen/acre on 10 Jun; thus, total nitrogen applied to the plots for the entire growing season was 170 lb/acre. On each of 4 Jun and 3 Jul, five 4 inch diam X 4 inch deep soil cores (each core containing at least 1 rice plant) were removed from each plot. Cores were washed and inspected for immature RWW. At maturity, plots were harvested (19 Aug) with a small plot combine. Yields were adjusted to 12% moisture. Insect counts were transformed using x + 0.5. All data were analyzed by 2-way ANOVA and DMRT.