Nematicidal effect of fluopyram and fluensulfone against rice root-knot nematode, Meloidogyne graminicola

. The comparative effectiveness of twelve non-fumigant pesticides was evaluated against the rice root-knot nematode, Meloidogyne graminicola. In vitro screening of pesticides at 50, 100 and 200 ppm exhibited substantial variability to inhibit hatching and to cause mortality of M. graminicola juveniles. Thereafter, the six most promising nematicides were selected for pot trials on rice 'Pusa Sugandha-5'. The plant grown in soil infested with M. graminicola suffered 32-36% suppression in dry shoot weight and grain yield. However, soil treatment with nematicides reduced adverse effects of nematodes but varied significantly with the treatments. Among the nematicides, soil application with fluopyram proved most effective and reduced the number of galls (76%) and reproduction factor (83%), resulting in 35-41% shoot weight promotion and grain yield production. Carbofuran was next in effectiveness followed by fluensulfone, phorate, carbosulfan and chlorpyriphos. Two years of trials in farmer's fields also confirmed the effectiveness of fluopyram, carbofuran and fluensulfone. We have demonstrated the nematicidal potential of fluopyram and fluensulfone for first time against M. graminicola in a series of in vitro, pot and field experiments.