Inhibition and Nematocidal Effect of Plant Extracts on Hirschmanniella spp.

The bioactivity of 24 extracts from 6 species plants in Yunnan province in China against Hirschmanniella spp.was reported.Results showed that the methanol extract from Tithonia spp.possessed the strongest nematocidal activity,followed by that from Nerium indium.There was distinctive differences in the nematicidal efficacy among various extracts from the different parts of the same plant,after 72 hours'treatment,the exact from the flower,leaf and skin of Nerium indium had nematocidal rate of 85.45%,73.15%,40.56%,respectively;the nematocidal rate of flower,new leaf,old leaf,and stem water extracts of Eupatorium adenophorum was 69.92%,37.76%,32.56%,27.64%,respectively.The methanol extracts of Nerium indium leaf,Eupatorium adenophorum were diluted to 2.5 times,5 times,10 times,20 times and 40 times by water,after 48h,the extract of Nerium indium leaf diluted to 2.5 times had the strongest activity,the extract diluted to more than 10 times had weak activity.After the leaf extracts of Nerium indium,Eupatorium adenophorum and Artemisia apiacea were shined for six hours by the sun light,their nematicidal activities were strengthened obviously.