Evaluation on Nematicidal Activity of Different Plant Extracts

The biological activity and virulence of various plant water extracts against the second juvenile of Meloidogyne incognita, nematicidal activity of plant extracts under different extracting solvents and illumination treatments ,were determined and compared in this study. The results showed that there was distinctive difference in the nematicidal efficacy of various extracts of plants and parts. The leaf water extracts of Tripterygium wilfondii,Nicotiana tabacum,Asarum sieboldii, Nerium indicum,Paederia scandens,Ricinus communis,Tagetes erecta and Lantana indica,had the killing rates of 100%,100%,100%,90.0%,87.1%,84.3%,77.3% and 32.4% respectively in 24 h; the killing rates of flower,leaf and stem water extracts of Tagetes erecta were 100%?77.3%and 48.2% respectively. The middle lethal concentrations of (LC 50 ) of the leaf water extracts of Nicotiana tabacum, Tripterygium wilfondii, Nerium indicum and Asarum sieboldi were 830.5 mg/L , 1770.8mg/L ,1336.4mg/L and 1020.4mg/L respectively. The nematicidal activities of plant extracts extracted by different solvents were also distinctively different. After the leaf water extracts of Tagetes erecta,Ricinus communis and Lantana indica were shined for six hours by the sun light , their nematicidal activities were intensived obviously .