Sensitivity of Meloidogyne Incognita to Fluopyram

Fluopyram is an SDHI fungicide that is being evaluated as a seed treatment and in-furrow application on row crops for management of fungal diseases and its effect on plant-parasitic nematodes.  Currently, there is no LD₅₀ value, data on nematode recovery, or effects of sub-lethal concentrations of fluopyram on nematode infection available for Meloidogyne incognita.  Based on an assay of nematode motility, LD₅₀ values of 5.21µg/ml and 0.78µg/ml were calculated for exposure durations of 2 hr and 24 hr, respectively.  There was some recovery in nematode motility after 24 hr from a 1 hr of exposure to the LD₅₀ concentration.  Sub-lethal concentrations of 3.9 µg/ml and higher for 1 hr of exposure resulted in less root-galling on tomato.  Though further studies are needed, these data suggest a very unique response by a root-knot nematode to fluopyram.