Fluopicolide, Indoxacarb, and Oxathiapiprolin Residues After Application to Flue-Cured Tobacco (Nicotiana tabacum L.)

Abstract

Pesticide residues found on cured tobacco (Nicotiana tabacum L.) remain a large concern to the allied tobacco industry. To quantify maximum expected cured leaf residues, 3 active ingredients (fluopicolide, indoxacarb, and oxathiapiprolin) were applied to flue-cured tobacco grown in 6 North Carolina environments from 2016 to 2018. Fluopicolide residues were consistently among the highest documented in this evaluation (7.25 mg/kg maximum), which was most likely a result of the compound having the shortest preharvest interval (PHI; 7 days) among the products tested. The highest indoxacarb residue was 2.15 mg/kg, which was identified in lower-stalk-position samples collected from 1 environment in 2018. Additional data suggest that indoxacarb residues are likely to be <2.0 mg/kg. Oxathiapiprolin was below the limit of quantification (0.09 mg/kg) in 98.6% of the samples analyzed and averaged 0.10 mg/kg in the lower-stalk position of 1 environment in 2017. It is plausible that residues from commercial farming operations would be lower than those reported because of integrated pest management (IPM) practices. Further investigations are warranted to better identify residues resulting from applications delivered using recommendations put forth by Cooperative Extension Services in the southern United States.