Control of Rice Water Weevil with Fipronil, 1996A

The experimental design was a RCB with 11 treatments and 4 replications. Plot size was 9 rows (7 inch spacing) by 25 ft. Adjacent plots were separated by a 2 ft alley. Rice was drill-seeded in Crowley silt loam at 90 lb/acre on 16 May and emerged on 22 May. Propanil and Bolero at 3 and 2 lb (AI)/acre, respectively, were applied for weed control on 11 Jun. Nitrogen was applied in a 3-way split of 90 lb N/acre as urea on 18 Jun and 30 lb N/acre on 13 and 22 Jul. Preplant treatments of fipronil were made with a CO2-pressurized back-pack sprayer at 18 gpa. and incorporated to a 2 inch depth with a tractor-mounted rotary tiller. Seed treated with fipronil was supplied by Rhone Poulenc Ag. Chemical Company. Permanent flood was established on 18 Jun. Furadan 3G was applied 14 d after permanent flood with a hand-shaker. On 11 and 12 Jul and on 25 and 26 Jul, five 4 X 4 inch (diam by depth) soil cores with an average of 9 plants/core were removed from plots. Soil was washed from the plant roots into a 40-mesh screen. The screen was immersed in salt water and RWW immatures were removed. Plots were harvested with a small combine on 25 Sep. Reported yields were adjusted to 12% moisture. Data were analyzed with ANOVA and LSD.