Evaluation of fluopyram for southern root-knot nematode management in tomato production in China

The southern root-knot nematode (Meloidogyne incognita) is one of major challenges tomato growers face in vegetable production; and phase out of methyl bromide and the restricted use of soil fumigants have been accelerating application of non-fumigant nematicides for control of this economically important plant-parasitic nematode. Fluopyram, a succinate dehydrogenase inhibitor fungicide, has been widely used to control fungal diseases in vegetable crops. However, in China, little information is currently available about the efficacy of fluopyram against M. incognita and its effect on tomato yield. In this study, the nematicidal effect of fluopyram on M. incognita was investigated under laboratory and field conditions in China. In the laboratory, fluopyram was highly toxic to the second-stage juveniles (J2) and the eggs of M. incognita with the median lethal concentration (LC50) value of 2.78 and 1.70 mg L-1, respectively. In the field trials, fluopyram was effective in reducing population levels of M. incognita, meanwhile enhancing plant growth, particularly at 480 and 640 g ha(-1) in two consecutive years, which was significantly greater than that of abamectin (a standard treatment) at 480 g ha(-1). Moreover, there was a yield increase of 21.4%-58.5% from the treatments with fluopyram at three doses compared with the untreated control. The results from this study indicated that fluopyram was effective against M. incognita and could be used for control of root-knot nematodes in tomato production, while enhancing tomato growth and yield.