Synergistic Activity of Dimethyl Disulfide Mixtures with Two Chemical Compounds against Meloidogyne incognita

The prevention and control of root-knot nematode disease is a worldwide challenge and there are not many varieties of pesticides for nematode control. To meet the huge market demand, the development of new nematicides is urgently needed. The lethal effects of soil fumigant dimethyl disulfide (DMDS) mixed with the chemical compounds copper sulfate (CuSO4) and ammonium bicarbonate (NH4HCO3) on Meloidogyne incognita were tested using the immersion method. The results showed that the LC50 of DMDS, CuSO4, and NH4HCO3 on the second stage juveniles (J2) of M. incognita were 19.28, 187,42, and 213.49 mg/L, respectively. The lethal effect on J2 were enhanced with the combination of DMDS and CuSO4 or NH4HCO3. The compound uses of DMDS (2.5 mg/L) and CuSO4 (46.58 mg/L) or NH4HCO3 (80.25 mg/L) have obvious synergistic effects on the control of M. incognita, with corrected mortalities of 97.09% and 94.00%, respectively. The synergistic effect of fumigant and chemical compounds on M. incognita was investigated to provide a new concept for the control of root-knot nematode disease.