Pine wilt disease(PWD) by the pine wood nematode(PWN) was first reported in Busan in 1998 and widely spread to pine forest in Korea. PWD was a heavily damaged in pine forest in Korea. For the control of PWD, several methods have been used such as fumigation of infected trees after cutting, aerial application of synthetic pesticides and trunk injection with nematicides. However these methods have some problems such as the side effects of pesticide, increased control cost, intensive input of labor and degradation of ecosystems by pesticides. Therefore this study was conducted to develop of control methods used plant extracts and actinomycetes to overcome defect.
Kyrgyzstan plant extracts were no nematicidal efficacy against PWN in laboratory. The effect of Kyrgyzstan plant extracts on the reproduction of PWN were different depending on kind of plant extracts. Plant extracts such as Salvia officinalis, Valeriana officinalis, Eucalyptus viminalis, Stachys baicalensis, Helichrysum bracteatum + Rosa rugosa + Bidens bipinnata + Hypericum perforatum + Anthemis nobilis + Inula helenium + Equisetum arvense + Mentha piperita + Vaccinium uliginosum, Calendula officinalis and Helleborus nige showed lower reproduction rate against PWN.
The efficacy of culture filterate of actinomycetes isolated from Korea on mortality of PWN showed more than 90% corrected mortality in 21 strains from the 32 strains in 2 fold treatment. Among those isolates, AM210, SG16, YD116 and YD315 had higher suppress efficacy in reproduction of PWN. YD116 is denominated as Streptomyces atratus YD116 by morphological and molecular identification.
Some substances were identified from Streptomyces atratus. I tested hydrazine hydrate which is similar to hydrazidomycin which has cytotoxicity among substances from Streptomyces atratus against PWN. 10 ppm of hydrazine hydrate showed 60.8% corrected mortality.
Some Actinomycetes isolated from Korea proved effect of nematicidal activity and decrease of reproduction on PWN. However, It is needed to be additional studies to identify the other actinomycetes which have nematicidal activity, screening of active substances and movement in the tree.
When trunk injection of some nematicidal active herbal plants, Zingiber officinale, Sophora falvescens, Quisqualis indica and Cyperus rotundus it was no nematicidal efficacy against PWN.