Control of Rice Water Weevil with Karate in a Dry-Seeded, Delayed Flood Culture, 1996

Abstract

Abstract The experiment was conducted at the TAMU Agricultural Research and Extension Center at Beaumont and was designed as a RCB with 10 treatments and 4 replications. Each plot was 15 ft X 8 ft and surrounded by a metal barrier to prevent movement of insecticides. On 17 Apr, plots were fertilized with urea at 68 lb nitrogen/acre and hand-planted with 90 lb seed/acre. Fipronil-treated seed was provided by Rhone-Poulenc Ag Company and was applied at the rate shown in the table. Fertilizer and seed were incorporated into dry soil (League clay) with a rake. On 18 Apr, plots were flush irrigated (temporary flood for 24 h, then drain). Rice emerged 24 Apr. From emergence of rice through the soil until application of the permanent flood on 16May(22d after rice emergence), rice was flush irrigated as needed. On 9 May, plots were sprayed with Facet 75DF, Bolero 8EC, and Basagran at 0.67 lb/acre, 3 pt/acre, and 1.5 pt/acre, respectively. Immediately prior to the permanent flood, designated plots were treated at the rates shown in the table with Karate 1EC or Fipronil 80WG using a 4 nozzle (tip size 800067, 50 mesh screens), hand-held, spray rig pressurized with CO2. Final spray volume was 29.7 gpa. Plots were fertilized -i with urea at 51 lb nitrogen/acre immediately before the permanent flood. Designated plots were treated post-flood at the rates and times shown in the table j with Karate 1EC and Dimilin 2L using the same methods and materials described for the pre-flood treatments. Furadan 3G was also applied post-flood at j the rate and time shown in the table to designated plots using a hand-held shaker jar. On each of 10 Jun and 8 Jul (25 and 53 d, respectively, after application of the permanent flood), five 4 inch diam X 4 inch deep soil cores (each core containing at least 1 rice plant) were removed from each plot. Rice j plants in cores were washed and immature RWW recovered from the roots. On 14 Jun, plots were fertilized with urea at 51 lb nitrogen/acre; thus, total nitrogen applied during the growing season was 170 lb/acre. At maturity, plots were harvested (26 Aug) with a small plot combine. Yields were adjusted to i 12% moisture. Insect counts were transformed using x + 0.5 and all data analyzed by 2-way ANOVA and DMRT.