Biocidal and Antinemic Properties of Aqueous Extracts of Ageratum and Coccinia Against Root-Knot Nematode, Meloidogyne Incognita In Vitro

Abstract

Plants are the one of the glorious and fascinating source of natural biopesticides. The present investigation was carried out for pytochemical analysis and to assess the nematicidal and nematostatic potential of aqueous extract of some plant parts viz., Ageratum conyzoides and Coccinia grandis against hatching and nematicidal behavior of root-knot nematode, Meloidogyne incognita in vitro conditions. The second stage juveniles (J2) were exposed at 24, 48 and 72 hours in different concentration (S, S/2, S/10, and S/100) of plant extracts. During in vitro condition inhibition of egg hatchability and J2 juveniles’ mortality varied according to the concentration of plant extract. The extract of Ageratum conyzoides leaves and stem exhibited highly promising mortality (98-100%) after 72 hours of exposure periods while the plant extract of C. grandis leaves and fruit showed minimum mortality (56-60%) after 24 hours of exposure periods. There was a gradual decrease in egghatching with an increase in the concentration of aqueous extract of plants. A. conyzoides leaves and stem extract elucidating most effectiveness in reducing egghatching and increase in mortality of J2 juveniles of M. incognita. Concentration of the extract was directly proportional to the mortality of second stage juveniles and inversely proportional to the egghatching. Phytochemical analysis in various solvent of different polarity such as ethanol, methanol, acetone, chloroform, petroleum and water marked the impressive outcome of alkaloids, saponins, tannins, flavonoids, protein, amines, glycosides, carbohydrate, steroids, mucilage, gums, terpenoids and phlobatannins in the plant extracts. The aqueous extract of Ageratum conyzoides showed maximum egg inhibition and J2 juvenile mortality due to the presence of phytoconstituents such as alkaloid, tannins, phenol, saponins, glycosides, flavonoids, carbohydrate, protein, mucilage/gum and phlobatannins while Coccinia grandis showed minimum egg inhibition and juvenile mortality.