Pesticide and Fungicide Residues in the Cultivation Substrate and Fruit Bodies of Tremella fuciformis

Various concentrations of six pesticides and two fungicides were applied separately to Tremella fuciformis cultivation substrate,and the effects of sterilization time on the rate of pesticide/fungicide dissipation were determined.Mushroom growth and residue levels in T.fuciformis fruit bodies cultivated on substrates treated with different concentrations of pesticides/fungicides were also recorded.Highest residue levels were recorded with chlorpyrifos:levels in substrate treated with 240,480 and 960mg/kg dry wt of this compound were 0.33,0.42 and 0.39mg/kg dry wt,respectively.No residual compound was detected when dichlorvos(400-1600mg/kg dry wt.)was applied,and residue levels below 0.05mg/kg dry wt were recorded when the pyrethroids cypermethrin(50-100 mg/kg),bifenthrin(50-100 mg/kg)or deltamethrin(12.5-25mg/kg)were used in treatments.Residue concentrations in the case of all other substrate treatments exceeded 0.05mg/kg dry wt.Residue levels were also determined in mature fruit bodies when the pesticides/fungicides were applied directly to T.fuciformis primordia or immature fruit bodies.Highest residue levels were again recorded with chlorpyrifos,with residue levels ranging between 0.33-184 mg/kg in fruit bodies treated directly with 480 to 1920mg/kg dry wt of this compound.No residual dichlorvos was detected in fruit bodies treated with 800-3200 mg/kg dry wt of the pesticide.Direct application of the six pesticides to primordia or immature fruit bodies had no significant effect on the further growth and development of T.fuciformis fruit bodies.However,no mycelial growth was observed when substrates were treated with250-1000mg/kg dry wt carbendazim or 350-1400 mg/kg dry wt thiophanate-methyl.Furthermore,when carbendazim(500-2000mg/kg dry wt)or thiophanate-methyl(700-2800mg/kg dry wt)was applied directly to primordia or immature fruit bodies,the mature fruit bodies were heavily deformed.