Evaluation of Botanicals Toxicants against Root-knot Nematode, Meloidogyne incognita in vitro

The present experiment was carried out to investigate the nematostatic and nematicidal potential of aqueous extracts of six weed leaves viz., Ageratum conyzoides, Eichornia crassipes, Ipomoea carnea, Nicotiana plumbaginifolia, Acalypha indica and Trianthema portulacastrum against root-knot nematode, M. incognita in vitro. The eggs and second stage juveniles (J2) of M. incognita were exposed to various concentrations viz., 1500 ppm, 1000 ppm, 500 ppm and 250 ppm of aqueous extracts of leaves. All the aqueous extracts damaged the eggs, reduced the hatching and caused paralysis and death of second stage juveniles (J2) of M. incognita. The highest inhibition in hatching and maximum mortality occurred by using A. conyzoides followed by E. crassipes, I. carnea, N. plumbaginifolia, A. indica and the least was observed by using T. portulacastrum. It can be concluded that the degree of effectiveness was found directly proportional to the dilutions of extract. The 1500 ppm concentration of aqueous extract of all weeds was found to be highly effective against hatching and mortality of M. incognita as compared to other concentrations.