Nemato-toxic analysis of several chopped plant leaves against Meloidogyne incognita affecting tomato In vitro and In...

Tomato plant is affected by several pathogens, including root-knot nematodes (RKNs), belonging to the genus Meloidogyne. Meloidogyne incognita is among the most potent pests infecting tomato roots. Therefore, it is of interest to discuss the management of Meloidogyne incognita using selected botanicals such as Cammelina benghalensis, Evolvulus nummularius, Gomphrena celosioides, Lindenbergia indica, Scoparia dulcis and Vernonia cinerea. The second-stage juveniles (J2s) of M. incognita were directly treated with the aqueous extracts of the botanicals at varied concentration ranging from 10-100%. 100% concentration of Lindenbergia indica was found to be the most toxic against the survival of J2s of M. incognita as compared to other concentrations. In vitro tests also showed the maximum inhibition in egg hatching at 100% concentration after seven days in the extract of Lindenbergia indica. Moreover, botanicals significantly reduced the infestations in relation to number of root galls, eggmasses/root and nematode population/250 g soil in pots. The plant treated with Scoparia dulcis leaves showed the highest nematicidal efficacy with maximum reductions in all the pathological parameters as compared to the untreated control. All treatments resulted in increased growth, physiological parameters and decreased pathological parameters of tomato.