Objective  Effect of pesticide application on the growth of Tremella fuciformis and recommendation of maximum residue limits (MRLs) on selected pesticides for the snow fungus cultivation were investigated.

  Method  On the fruiting bodies of a major variety of T. fuciformis, Tr21, 10 pesticides of 8 different types were sprayed separately. Residues and metabolites of each pesticides on the harvested snow fungus were analyzed by GC-MS/MS and LC-MS/MS. A risk assessment was carried out to evaluate the potential long-term dietary exposure to human health risk, then MRLs were recommended.

  Result  Growth of Tr21 was inhibited by the conventional applications of prochloraz emulsifiable oil, pyridaben and acetamiprid micro-emulsion (2 000-4 000 mg·L⁻¹) or isoprocarb emulsifiable oil (4 000 mg·L⁻¹). However, when the recommended formulation and method were used, the pesticide applications not only allowed the fungi grow vigorously, but also reduced the residual levels to within the limits for safe consumption. The MRLs of bifenthrin, acetamiprid, abamectin, prochloraz, imidacloprid, isoprocarb, and pyridaben were recommended as 1, 0.7, 0.1, 0.02, 5, 0.1, and 0.01 mg·kg⁻¹, respectively. Those could provide a protection against the chronic dietary risk in the range from 3.07 to 306.92.

  Conclusion  The above mentioned 7 pesticides could be safely applied for T. fuciformis cultivation under the recommended methods. The dietary exposure to pesticides residues on snow fungus could be acceptable if the pesticide residual levels were lower than recommended MRLs.