Furadan Formulations and Application Methods for Rice Water Weevil Control, 1993

Abstract

Abstract Different formula tions and application methods of the insecticide, Furadan, were evaluated for control of rice water weevil at the Rice Research Station, Crowley, LA. Plots, 1.22 × 5.47 m, were collectively leveed and arranged in a RCBD with 4 replicates and 4 treatments. Fertilizer was incorporated pre-plant and applied broadcast 3 wk post-flood at 50.6 kg (13-13-13) and 101.2 kg (21-0-0) N-P-K/ha respectively. Plots were drill seeded to Crowley silt loam (17.8 cm row spacing) with ‘Cyprus’ rice at 112.5 kg seed/ha on 12 May, flush irrigated 21 and 28 May, and permanently flooded 7 Jun. Propanil was applied at 3.34 kg/ha on 26 May using a CO, backpack sprayer delivering 141.9 liters/ha at 1.8 kg/cm2 for weed control. Benomyl was aerially applied at 0.56 kg/ha on 28 Jun to control rice blast. Foliar applications of Furadan 4F were made 3 d pre-flood at 1.14 kg/ha using a CO2 backpack sprayer delivering 141.9 liters/ha at 1.52 kg/cm2 with 80015 flat-fan nozzles on a 0.91 m boom. Furadan 4F, adsorbed onto ammonium sulfate fertilizer (N-P-K = 21-0- 0), was applied 2 wk post-flood at 1.14 kg/ha using a hand-held shaker. Furadan 3G was applied 2 wk post-flood at 0.68 kg/ha using a hand-held shaker. Three randomly selected soil samples per plot were taken 22 and 29 Jun, and 7 and 13 Jul using a 10.2 × 10.2 cm core sampler. Individual samples were washed through a funnel, fitted with wire screen, into a 35 mesh screen sieve. Collected rice water weevil (RWW) larvae and pupae were floated in a saturated NaCl solution, counted and corrected for the number of rice plants per core. Five plants per plot were measured for height immediately prior to harvesting the center 4 rows of each plot on 1 Sep using a Kubota combine. Moisture content of harvested grain was determined and then standardized to 12% for calculation of yield. Statistical analysis was performed using ANOVA succeeded by orthogonal contrasts to separate the following mean comparisons: 1) Untreated vs treated; 2) Furadan 4F foliar spray vs Furadan 4F impregnated on fertilizer and broadcast applied; 3) Furadan 3G vs Furadan 4F foliar and broadcast applied. These contrasts were performed for all collection dates except the 1st date of 22 Jun, because application of the broadcast treatments were not made until after the plots were sampled. Therefore, these plots were considered as untreated and the following contrast performed: 1) Furadan 4F foliar application vs Untreated. Additionally, RWW immature counts corrected and uncorrected for the number of plants per core were analyzed. Both analyses produced similar results; thus, only uncorrected RWW immature means are presented in the table. All analyses were conducted at the 0.05 probability level.