Control of Rice Water Weevil on Dry-Seeded Rice with Diflubenzuron at Beaumont,1996

Abstract

Abstract The experiment was conducted at the TAMU Agricultural Research and Extension Center at Beaumont. The experiment was designed as a RCB with 8 treatments and 4 replications. Each plot was 15 ft X 8 ft and surrounded by a metal barrier to prevent movement of insecticides. On 19 Apr plots were broadcast planted by hand into a dry seed bed (League clay soil) at 90 lb seed/acre and fertilized with urea at 68 lb nitrogen/acre. Seed and fertilizer were incorporated with a rake followed by a flush irrigation (temporary flood for 24 h then drain). Rice emerged 27 Apr. From emergence to application of the permanent flood on 18 May (21 d after emergence), rice was flush irrigated as needed. On 9 May Facet 75DF, Bolero 8EC, and Basagran were applied at 0.67 lb, 3 pt, and 1.5 pt/acre, respectively. Rice was fertilized with urea at 51 lb nitrogen/acre immediately before the permanent flood. Diflubenzuron treatments were applied with a 4 nozzle (tip size 800067, 50 mesh screens), hand-held, CO2 pressurized spray rig. Final spray volume was 37 gpa. Furadan 3G was applied with a hand-held shaker jar. On each of 14 Jun and 31 Jul (27 d and 74 d, respectively, after application of the permanent flood) five 4 inch diam X 4 inch deep soil cores (each core containing at least 1 rice plant) were removed from each plot. Rice plants in cores were washed and immature RWW recovered from the roots. Plots were fertilized at panicle differentiation (19 Jun) with urea at 51 lb nitrogen/acre. Thus, total applied nitrogen/acre was 170 lb. Plots were harvested with a small plot combine on 4 Sep. Yields were adjusted to 12% moisture. Insect counts were transformed using x + 0.5. All data were analyzed by 2-way ANOVA and DMRT.