• Korean Journal of Organic Agriculture
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• v.29 no.1
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• pp.97-109
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• 2021

Plant parasitic nematodes are causing significant damage in crop production. There is a need to develop eco-friendly nematicide that reduces the damage of nematode and has little effect on the environment and human. In this study, we have isolated a substance having nematicidal activity from Ginkgo biloba L. outer seedcoat. Studies of G. biloba L. outer seedcoat are insufficient compared to the seed and leaves due to their odor and toxicity. The dried G. biloba L. outer seedcoat was extracted with dichloromethane:methanol (1:1) and fractionated into hexane, ethyl acetate and H₂O. Four steps TLC were performed from EtOAc fraction to purely isolate GB4-3 with nematicidal activity. To compare nematicidal activity, G. biloba L. seedcoat methanol extract and purified GB4-3 were investigated in terms of treatment concentration and time. As a result, the nematicidal activity increased with concentration and time. In the place treated with 20 ㎍/mL of crude G. biloba L. seedcoat MeOH extract, strong activity appeared after 12 hours, and 46% nematicidal activity shown after 18 hours. About 69% of nematicidal activity was confirmed in the place where GB4-3 purified from outer seedcoat was treated with 20 ㎍/mL, and the possibility of development as nematicide was very high. This study could be used as a basic data for the development of a nematode preparation from G. biloba L. outer seedcoat.

• The Korean Journal of Pesticide Science
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• v.20 no.1
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• pp.30-34
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• 2016

To evaluate the efficacy of natural nematicides for the control of root-knot nematode in strawberry greenhouses, commercial essential oils were examined by 24-well culture plate bioassay for their nematicidal activities against second-stage juveniles and eggs of Meloidogyne hapla. Based on the mortality of M. hapla juveniles at a concentration of $125{\mu}g/mL$, the most active essential oil was Alpinia galanga (100%), followed by Carum carbi (22.3%), Eugenia caryophyllata (9.4%), Cinnamonum zeylanicum (7.2%), Mentha pulegium (2.4%), and Foeniculum vulgare (2.1%). Moreover, A. galanga significantly reduced hatching at 7, 14, and 21 days after treatment. The volatile constituents identified in the A. galangal oil were methyl cinnamate (87.4%), 1,8-cineole (4.4%), ${\beta}$-pinene (2.5%), ${\alpha}$-pinene (2.2%), and p-cymene (1.1%), as major constituents. Results of this study show that A. galangal essential oil and its major constituents may serve as an environmental friendly agent of a promising natural nematicide to control Meloidogyne spp.