Control of Rice Water Weevil with Fipronil in A Water-Seeded, Continuous Flood Culture–Eup Study, 1996

The experiment was conducted at the TAMU Agricultural Research and Extension Center at Beaumont and was a non-replicated experimental use permit (EUP) study with 4 treatments. Plot size was 3 acres. On 26 Mar, plots were fertilized by air with 110-40-0 at 113 lb nitrogen/acre. On the same day, plots were treated by air with Ordram 15G at 29.2 lb product/acre. Fertilizer and herbicide were incorporated into dry soil (League clay) with a “do-all”. On 27 Mar, a designated plot was treated with Fipronil 80 WG at 0.0325 lb (AI)/acre. The treatment was applied to dry soil using a large, 2-person spray boom equipped with 11 nozzles (tip size 80015, 50 mesh screens) and pressurized with CO2. Final spray volume was 10.6 gpa. Following application, the treatment was incorporated with a spike tooth harrow. Plots were permanently flooded then planted by air with sprouted seed on 30 Mar. Untreated and fipronil-treated seed were provided by Rhone-Poulenc Ag Company. Sprouted seed was treated with fipronil at the Beaumont Center by Rhone-Poulenc Ag Company officials. Seeding rate for all plots was 100 lb dry seed/acre. Due to levee breakage, plots were drained 6 Apr and reflooded by 8 Apr. Rice emerged through the water about 17 Apr (14 d after application of the permanent flood). On 30 Apr (13 d after rice emergence through the water) Furadan 3G was applied by air to a designated plot at 0.5 lb (AI)/acre. On 3 Jun, rice was fertilized with urea at 60 lb nitrogen/acre; thus, total nitrogen applied during the growing season was 173 lb/acre. All aerial applications were conducted by M&M Air Service of Beaumont. On each of 7, 15, 23 May; 6 Jun; and 4 Jul; twenty 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. Plots were not harvested due to mechanical and weather problems. Insect counts were transformed using x + 0.5 and data analyzed by 1-way ANOVA and LSD.