بررسی آزمایشگاهی عصاره‌های پودر خشک برخی گیاهان بر تفریخ تخم و مرگ‌و‌میر لارو سن دوم نماتد ریشه‌گرهی (Meloidogyne javanica)

Root-knot nematodes (Meloidogyne spp.) are one of the most important plant-parasitic nematodes with a broad host range which causes irreparable damage to plants. During the recent years, with changes made in the perspective regarding the development of organic products and the decrease in use of pesticides, non-chemical methods using natural compounds such as herbal extracts have come into focus as a suitable and effective replacement to control plant-parasitic nematodes. In this study, the effect of dry powder extracts of Eucalyptus globulus Labill, Falcaria vulgaris Bernh, and Galium tricornatum Dandy, on egg hatching and mortality of second-stage juveniles (J2s) of root-knot nematode (M. javanica), was evaluated. The experiment was carried out in a completely randomized design with three replications under laboratory condition. 100 eggs or J2s of M. javanica were separately allocated to representative cells of a 96-well polystyrene round bottom plates and different levels of plant extracts were added to the final volume of 200 microliters and were kept in a dark place at 27°C for 96 hours. In the egg-hatching experiment, the number of hatched J2s were counted after 96 and 144 hours treatment with dry powder extracts of tested plants in concentrations of 0(control), 0.25, 0.5, 0.75, 1, 1.25 and 1.5 % (v/w); and in the J2s mortality experiment, the number of dead J2s were counted after 48 hours treatment with dry powder extracts of F. vulgaris, and G. tricornatum in concentrations of 0(control), 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 1, and 2%, as well as dry powder extracts of E. globulus in concentrations of 0(control), 0.25, 0.375, 0.5, 0.375, 0.5, 0.625, 0.75, 0.875, 1, 1.25 and 1.5%. Sterile distilled water was used as control. The results indicated that all the used levels of dry powder extracts of E. globulus, F. vulgaris, and G. tricornatum decreased egg-hatching of M. javanica by 89, 86, and 95% respectively, as compared to control. Regarding the mortality of the J2s, it was shown that dry powder extracts of E. globulus at the rate of 0.75% lead to a mortality rate of 88% and in higher concentrations the mortality rate was higher as well; however, F. vulgaris and G. tricornatum showed 100% mortality of J2s at the rate of 1 and 2 % while there was no significant difference in other concentrations with the control. In this study, the positive effect of dry powder extracts of eucalyptus on mortality rate of J2s and egg-hatching of M. javanica was proven.