Control of Rice Water Weevil with Exp 80698A 75 Fs Applied After the Permanent Flood in a Dry-Seeded, Delayed Flood Culture, 1997

Abstract

Abstract The experiment was conducted at the TAMU Agricultural Research and Extension Center at Beaumont and was designed as a RCB with 5 treatments and 4 replications. Each plot was 15 ft X 8 ft and surrounded by a metal barrier to prevent movement of insecticides and fertilizer. On 1 May, plots were fertilized with urea at 113 lb nitrogen/acre and planted with 100 lb of untreated or EXP 80698A 75 FS-treated seed/acre at the rate shown in the table. Fertilizer and seed were incorporated into dry league soil with a rake. Immediately after incorporation, plots were flushed (24-48 h temporary flooding, then draining). Rice emerged through soil on 9 May. On 28 May, plots were sprayed with Facet 75 DF at 0.5 lb/acre, crop oil concentrate at 2 pt/acre, Prowl 3.3 EC at 2 pt/acre, and Basagran at 1.5 pt/acre. Herbicides were applied by hand with a 20 ft spray boom pressurized with CO2. Immediately before the permanent flood on 30 May (21 d after emergence of rice through soil), selected plots were treated with EXP 80698A 75 FS at 0.05 lb (AI)/acre. On 2 Jun, (3 d after application of the permanent flood), selected plots were treated with EXP 80698A 75 FS at 0.05 lb (AI)/acre and Karate at 0.03 lb (AI)/acre. All liquid insecticides were applied with a 4 nozzle (tip size 800067, 50 mesh screens) hand-held, spray rig pressurized with CO2. Final spray volume was 16.0 gpa. On 16 Jun and 10 Jul, plots were fertilized with urea at 50 and 30 lb nitrogen/acre, respectively; thus, total nitrogen applied during the growing season was 193 lb/acre. On each of 25 Jun and 10 Jul (26 and 41 d, respectively, after application of the permanent flood), five 4-inch diam X 4 inch deep soil cores (each containing at least 1 rice plant) were removed from each plot. Rice plants in cores were washed and immature RWW recovered from the roots. At maturity, plots were harvested (5 Sep = 119 d from emergence of rice through soil) with a small plot combine. Yields were adjusted to 12% moisture. Insect counts were transformed using x + 0.5 and all data analyzed by 2-way ANOVA and DMRT.