Interaction of Root-Knot Nematode (Meloidogyne Javanica) and Tomato As Affected By Hydrogen Peroxide

Interaction of Root-Knot Nematode ( Meloidogyne Javanica ) and Tomato As Affected By Hydrogen Peroxide The effect of hydrogen peroxide (H 2 O 2 ) on root-knot nematode (RKN, Meloidogyne javanica ) in tomato was investigated. Soil drenching with exogenous H 2 O 2 was done using seven H 2 O 2 concentrations (1, 10, 100, 250, 500, 750 and 1000 mM) at different application times (24 hours before the time of plant inoculation with the RKN (T1), at the time of inoculation (T2), and 24 hours after the inoculation time (T3). The nematode reproduction rate (eggs/g fresh root) was significantly reduced in all H 2 O 2 treatments compared with the untreated control. The lowest reduction in nematode reproduction occurred at 10 mM H 2 O 2 . The application times T1 and T2 were significantly higher in reducing the reproduction rate than T3 at 250, 750 and 1000 mM H 2 O 2 . The content of endogenous H 2 O 2 in the treated plants was significantly higher than in the non-treated plants. Some phytotoxicity was apparent at the higher concentrations of H 2 O 2 (≥ 500 mM) in the treated plants due to the accumulation of the endogenous H 2 O 2 . The treatments with 1 and 10 mM H 2 O 2 did not differ from the untreated control in plant chlorophyll content while the content was significantly reduced at the higher concentrations. Exogenous application of H 2 O 2 may have a direct effect on the nematode reproduction and an indirect effect on the treated tomato plants that can be elicited by H 2 O 2 to resist the nematode infection.