| 摘要 |
PROBLEM TO BE SOLVED: To improve the viability of a tree such as pine without using any chemical by growing a resistant tree by letting a current intermittently flow to the object tree, suppressing the multiplication of pathogenic eelworms invading the tree, and inducing resistance. SOLUTION: The current is let intermittently flow to an object tree 13 while using a power unit 10, output terminal 11 and lead wire 12 or the like, the multiplication of pathogenic eelworms such as Bursaphelenchus lignicolus invading the object tree 13 is suppresse and weakened, and the resistant tree is grown while inducing resistance against the pathogenic eelworms to the object tree 13. In this case, it is preferable that the object tree 13 is nursery stock. |
