Control of Rice Water Weevil with Fipronil in a Water-Seeded, Pinpoint Flood Culture-Eup Study, 1997

Abstract

Abstract 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 3 treatments. Plot size was 2.9 acres and plots were separated by earthen levees. On 16 Apr, plots were fertilized with urea at 113 lb nitrogen/acre and treated with Ordram 15 G at 27 lb/acre. Fertilizer and herbicide were applied by air and incorporated into dry League soil with a spike tooth harrow. On 18 Apr, plots were flooded and planted by air (M&M Air Service) with untreated or fipronil-treated, sprouted seed at 100 lb dry seed/acre. Sprouted seed was prepared by soaking untreated seed for 24 h then draining and drying for 24 h. Fipronil was applied to sprouted seed using Rhone-Poulenc Ag Company’s seed treater. On 21 Apr, plots were drained and were reflooded on 29 Apr. On 3 May, rice emerged through the water which was approximately 4 inches deep. On 9 May (6 d after rice emergence through water), a selected plot was treated by air with Furadan 3 G at 20 lb/acre. On each of 20 May, 27 May, 3 Jun, and 10 Jun (17, 24, 31, and 38 d after rice emergence through water), 20, 4 inch diam X 4 inch deep soil cores (each containing at least 1 rice plant) were removed from each plot. Cores were washed and inspected for immature RWW. On 28 May and 10 Jul, plots were fertilized by air with urea at 30 lb nitrogen/acre, thus, total nitrogen applied to the plots during the entire growing season was 173 lb/acre. At maturity, plots were harvested (26 Aug) with a commercial rice combine equipped with a Global Positioning System which enabled yields from each plot to be collected and recorded. Insect counts were transformed using Vx + 0.5 and data analyzed by 1-way ANOVA and LSD.