Control of Rice Water Weevil with Fipronil, 1997

The experimental design was a RCB with 9 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 18 May and emerged on 27 May. Propanil (Stam 4 E) and thiobencarb (Bolero 8 E) at 3 and 2 lb (AI)/acre, respectively, were applied for weed control on 12 Jun. Nitrogen was applied in a 2-way split of 90 lb N/acre as urea on 2 Jul and 60 lb N/acre on 26 Jul. Preplant treatments were made with a CO2-pressurized backpack 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. Plots were flush irrigated (temporary flood for 24 h, then drained) on 23 May and 14 Jun. Permanent flood was established on 2 Jul. Furadan 3 G was applied 14 d after permanent flood with a hand-shaker. On 25 and 31 Jul three 4X4 inch (diam by depth) soil cores with an average of 4 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 Yanmar combine on 7 Oct. Reported yields were adjusted to 12% moisture. Data were analyzed with an ANOVA and means separated with LSD.