Pesticide residues on tobacco have received increasing attention in recent years. While pesticide residue evaluations have been conducted for many years in tobacco, recent legislation granting the Food and Drug Administration regulatory oversight of tobacco products has brought the need to determine expected residues from pesticides used in tobacco production into focus. As part of an on-going program at North Carolina State University, several pesticides are evaluated over a three-year period. The objective of the research is to establish the maximum expected residues on cured leaf that would result from a maximum labeled application and minimum pre-harvest interval (PHI).

Residues of four pesticides (bifenthrin, chlorantraniliprole, clothianidine, and flubendiamide) were measured on flue-cured tobacco at two locations in North Carolina in 2010, 2011, and 2012. Each product was applied according to maximum usage and minimum PHI according to the current or most recent US label. Treatments were applied to flue-cured tobacco grown on research stations near Rocky Mount, NC, and Kinston, NC. Tobacco was managed according to Extension recommendations and harvested four times by individual stalk position. Cured leaf pesticide residues were determined by Global Laboratories in Wilson, NC.

General observation shows that bifenthrin, chlorantraniliprole, and clothianidin had very low residues that decrease from the lower stalk position to the middle and upper stalk positions. Many results for these two pesticides were below detectible limits. Alternatively, the results for flubendiamide are relatively high when compared to the other compounds. Across all stalk positions and all locations; the highest mean residues observed for bifenthrin, chlorantraniliprole, clothianidin, and flubendiamide were 3.745, 7.425, 1.014, and 25.835 mg/kg, respectively. The presentation will further summarize the testing results from the entire research cycle of 2010-2012 with data presented by individual year, location, compound, and stalk position. Additional information will be presented regarding changes to and the future of the Pesticide Residue Testing Program.