Activity of four nematicides against Meloidogyne incognita race 2 on tomato plants

Abstract Meloidogyne incognita is one of the most important causes of disease in protected vegetable cultivation in North China Plain, but chemical control options for it are currently limited. In the present study, we measured activity of four nematicides with M. incognita race 2 in the laboratory and greenhouse pots. Fluensulfone and fluopyram had a greater negative effect on the motility of M. incognita second‐stage juveniles (J2) than avermectin B1a (AV‐B1a) and fosthiazate had, especially at low concentration, with respective EC 50 values of 0.29, 0.13, 0.68 and 2.48 mg/L. AV‐B1a significantly and uniquely inhibited egg hatching, which indicated that it was the only nematicide that could readily be transported across the eggshell. In greenhouse pots, fluensulfone (10 mg −1 ) and fluopyram (1 and 10 mg −1 ) caused the greatest inhibition of formation of galls in tomato roots, with decreases of 98.6%, 96.2% and 99.2%, respectively. This indicated that some M. incognita J2 lost their root penetration ability without losing their motility.