MULTIFACTOR EXPLORATION OF THE INSECTICIDAL EFFICACY AND DEGRADATION OF SULFURYL FLUORIDE IN STORED WALNUTS

The navel orangeworm (NOW), Amyelois transitella, is a pest of concern to countries that import inshell nuts from California. The individual and interactive effect(s) of pressure, temperature, time, and sulfuryl fluoride (SF) dose on NOW egg mortality and residue off-gassing from stored walnuts are quantitatively delineated; a multifactorial experiment was generated and the results were analyzed using Design Expert 7.0 (Stat-Ease, Inc.). The mathematical models generated in this study can be used as predictive tool for ensuring that targeted mortality and minimum residues levels are achieved during individual fumigation events. This should be particularly useful to industry when “quarantine” control of insects (i.e., ≥ 99.9986% mortality) and MRL verification is required to move commodity through foreign trade and marketing channels.