Study On Joint Effects Of Three Pesticides And Ni To The Earthworm

The effect of single and joint tocixity to earthworm(Eisenia fetida)of triazop hos.cyhalothrin?carbendazim and nickel chloride were expolored usingartificial soi 1 test for acute toxicity?antioxidant enzyme activity toxicity and subacute toxicity te st,the results are as follows:Acute toxicity experiment indicated that:toxicity were carbendazim>triazophos>cyhalothrin>nickel chloride.7 d and 14 d median lethal concentration(LC50)o f carbendazim?triazophos?cyhalothrin and nickel chloride on earthworms were 20.31?331.10?897.91?6065.62 mg/kg and 13.19?122.00?656.68?5278.73 mg/kg,r espectively.The mixtres presented different joint effects.Triazophos and cyhalothrin presented synergistic effect by binary mixture.7 d and 14 d addition index(AI)w ere 4.81 and 9.00,respectively,and as exposure extended,synergy effect were more obvious.In termary mixture of triazophos+cyhaiothrin+carbendazi,triazophos+cyhaloth rin+nickel chloride,triazophos+carbendazim+nickel chloride all presented synergistic effect.7 d-AI were 8.80.0.36 and 2.62,respectively,14 d-AI were 8.80.0.36 and 2.62,15.60?9.00 and 0.80,respectively.While the mixture of cyhalothrin+carbenda zim+nickel chloride presented additive effect,7 d-AI and 14 d-AI are 0.003 and 0.19,respectively.The quatermary mixture exhibited synergistic effect,7 d-AI and 14 d-AI are 2.42 and 2.85,respectively.Test on antioxidant enzyme activity showed that:triazophos or cyhalothrin has different effects on CAT?POD and SOD activity.Triazophos CAT activity were inc reased and then inducted by triazophos,POD activity was not obvious,SOD activit y was suppressed.CAT activity was raised,POD activity increased then inducted,S OD activity was raised by cyhalothrin.CAT and POD activity were increased remar kably,and SOD system was disordered by mixture of triazophos and cyhalothrin.In the subacute toxicity test:toxicity were carbendazim>cyhalothrin>triazophos>n ickel chloride.The lowest observation effect concentration(LOEC)of triazophos,cyh alothrin,carbendazim and nickel chloride on earthworm weight were 53.55?12.50.4.28 and 2058.00 mg/kg,respectively,and the LOEC on earthworm reproduction wer e 53.55?6.25?2.14 and 1029.00 mg/kg,respectively.When they were mixed,the L OEC of weight and reproduction was different in mixture.Weight LOEC reduced 52.5 and 2.04 times,reproduction LOEC reduced 52.5 and 1.02 times in the binary mixture of triazophos and cyhalothrin.Weight LOEC reduced 69.5?2.7 and 91.1 ti mes,reproduction LOEC reduced 315?4.5 and 178.3 times in the mixture of triazop hos?cyhalothrin and carbendazim.in the mixture of triazophos?cyhalothrin and nic kel chloride,reproduction LOEC reduced 630?11.0 and 333.0 times.In the mixture of triazophos?cyhalothrin?carbendazim and nickel chloride:weight LOEC reduced 103.0?7.3?237.8 and 302.6 times,reproduction LOEC reduced 103.0?8.2?118.9 an d 151.3 times.Throught evaluated reproduction results,triazophos+cyhalothrin,triazo phos+cyhalothrin+carbendazi,triazophos+cyhalothrin+carbendazi+nickel chloride presen ted additive effect?antagonism effect?additive effect.