Root-knot nematode control with dimethyl disulfide (dmds) in protected tomato and melon in Italy

Root-knot nematode (RKN) (Meloidogyne spp.) attacks cause severe yield losses to melon and tomato in protected crops. This is a big problem for the European melon and tomato growers because effective fumigants have lost registration and effective solutions are not available as registered products, except through few national derogations. A new soil fumigant, dymethyl disulfide (DMDS), by Arkema, is now in the evaluation process for Annex 1 inclusion in European Union. Therefore, five different trials (tomato and melon) were carried out in Southern Italy (Apulia, Basilicata and Sicily) using the new fumigant DMDS in comparison to the nematicide fumigant 1.3D (140-180 L/Ha) and untreated controls. DMDS EC formulation (94.1%) was applied at rates of 300 and 400 L/Ha in drip chemigation, using virtually impermeable film (VIF) to cover soil and chemigation lines. In all trials and treatments root gall indices were significantly lower than those observed in the untreated controls with no significant differences among the fumigant treatments. Moreover, significant melon and tomato yield increases were also observed in comparison to the untreated controls (814-833% and 197-218%, respectively) confirming the excellent efficacy of DMDS against RKN in protected crops. Thanks to these results, derogations have been granted to the product for commercial use in Italy in the last years, before its final registration.