Hormesis effect of three nematicides on the dispersal of Ditylenchus destructor

Effects of low-dose aldicarb,emamectin benzoate and profenofos on the dispersal activity of Ditylenchus destructor were tested by using sand columns and water agar plate.The results showed that the movement of nematodes was adversely affected at the highest concentration of nematicides (5 μ g/mL nematicides solution in sand columns and 0.1 μ g/mL nematicides solution which was used to dip nematodes for 24 h),while the percentage of nematodes that moved through sand columns was increased by more than 10%(P－3 μ g/mL nematicides solution in sand columns and 10－2 ,10－3 μ g/mL aldicarb,10－4 ,10－5 μ g/mL emamectin benzoate solution which was used to dip nematodes for 24 h),which was a Hormesis phenomenon.The hormetic effect of nematodes that had treated by low-concentration of profenofos (10-1 μ g/mL) was not observed.In water agar plate bioassay,low-dose nematicides could promote the dispersal of nematodes,but the hormetic effects were less than that in sand column assay.