Control of Rice Water Weevil with Fipronil, 1995

Abstract

Abstract Various formulations and application times of fipronil were compared with Furadan 3G and an untreated check for control of RWW. The experimental design was a RCB with 4 replications. Plot size was 9 rows (7 inch row spacing) X 25 ft with a 2 ft alley between plots. Rice was drill-seeded in a Crowley silt loam at 115 lb/acre on 11 May and emerged on 18 May. Broadcast applications of fipronil 1.65G were applied with a hand-shaker to either preplant dry soil and lightly incorporated with a hand-rake on 11 May or to dry soil immediately prior to application of permanent flood on 8 Jun. Fipronil 80WG was applied with a CO2-powered back pack sprayer with a 3 nozzle. (TeeJet 8002 flat fan) boom delivering 16 gpa at 22 PSL to either preplant dry soil and lightly incorporated with a hand-rake on 11 May or to dry soil tank-mixed with propanil at 4.0 lb (AI)/acre on 6 Jun. Furadan 3G was applied 7 d after permanent flood with a hand-shaker. Propanil and Bolero at 3.0 and 2.0 lb (AI)/acre, respectively, were applied for weed control on 6 Jun. Permanent flood was established on 8 Jun. Londax at 0.04 lb (AI)/acre was added to the permanent flood on 12 Jun. Nitrogen was applied in a 3-way split of 90 lb/acre on 8 Jun and 30 lb/acre each on 9 and 16 Jul. On 29 and 30 Jun and on 13 and 14 Jul five 4X4 inch (diam by depth) soil cores with an average of 7 plants/core were removed from each plot. Soil was washed from plant roots into 40-mesh screens. Screens were immersed in salt water and RWW immatures were recovered and counted. The center 4 rows X 20 ft of plots were harvested on 12 Sep. Reported yields were adjusted to 12% moisture.