NEMATICIDAL ACTIVITY OF ERITREAN WEED PLANTS AGAINST THE ROOT-KNOT NEMATODE MELOIDOGYNE INCOGNITA

The nematicidal potential of ethanol and aqueous extracts of ten wild plant species distributed on agricultural land of Eritrea against root-knot nematode, Meloidogyne incognita, was studied. Three concentrations of each plant extract were tested against egg hatching and mortality of second-stage juveniles (J2) of M. incognita at 24, 48 and 72h exposure time. Significant mortality and egg hatching inhibition were observed with aqueous and ethanol extracts of Datura stramonium. Similar type of hatch inhibition also occurred with both types of extracts of Heliotropium indicum. From tested extracts, J2 mortality ranged from 8 to 100% for hot water extracts and 26 to 100% in for ethanol extracts. The nematotoxicity of the tested plants increased with an increase in concentration and exposure time and vice versa. The hot water and ethanol extracts of D. stramonium caused 75-100% mortality and 57-100% inhibition in egg hatch, respectively. This M. incognita juvenile mortality was 74-100% in the case of H. indicum. Among the tested extracts, hot water and ethanol extracts of Lantana camara and Xanthium strumarium, respectively, were least effective.