Control of Rice Water Weevil with Carbofuran, 1992

The study was conducted in a commercial rice field farmed by Bill Dishman in Jefferson County, TX. The experiment consisted of 5 treatments with 4 replications arranged in a RCBD. Plot size was 16 ft × 8 ft. The field was broadcast planted at 110 lb seed/acre on 23 May and rice emerged 30 May. Nitrogen was applied at 50 lb and 100 lb/acre at planting and preflood, respectively. Phosphorus was applied at 40 lb/acre at planting. Propanil was applied preflood at about 3 to 4 lb (AI)/acre. The field was flush irrigated until 2 Jul when the permanent flood was initiated. Metal barriers were placed around all plots which were infested immediately before the permanent flood with 50 adult RWW per plot. RWW were collected from untreated, flooded rice. Granular carbofuran was applied with a hand shaker at the rates and times described in the table. Liquid treatments were applied with a 4 nozzle spray rig with 800067 tips and 50 mesh screens. Spray volume was 20 gal/acre. Rates and times are described in the table. Flowable Furadan was applied to urea by slowly pipetting the liquid onto the fertilizer in a glass jar which was continually agitated for 5 min. The carbofuran-coated urea was air dried and clumps were manually broken up and applied by hand. The carbofuran-coated urea was applied at 51 lb N/acre and 1.0 lb carbofuran/acre immediately before the permanent flood. On 27 Jul (25 d after initiation of the permanent flood) 10, 4 inch diam by 4 inch deep soil cores each containing about 1 plant were removed from each plot. Cores were washed and roots inspected for RWW larvae and pupae. Plots were not harvested because of poor and inconsistent weed control. Data were analyzed by ANOVA and where applicable means separated by DMRT.