2024-03-28T22:52:58Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/326042022-11-17T02:08:08Zhdl_2115_20046hdl_2115_138Windthrow resistance of apple trees grafted in an orchardKoizumi, AkioAraki, HajimeHori, HirotakaInagawa, Yutakawindthrow resistancecritical wind velocityuprooting strengthapple treespull-down test470Pull-down tests were conducted for apple trees grafted in an orchard and for support posts in order to discuss the failure mode in windthrow damage, the effect of rootstock types on the uprooting strength, and the reinforcing effect of support posts on young trees. The test samples were 10 mature trees (20–23 years old) of 3 varieties grafted on two types of rootstocks, 3 young trees (7 years old) grafted on dwarf rootstocks, and 9 support posts of larch logs and steel pipes. The failure modes were found to be uprooting for mature trees and rootstock breakage for young trees. The uprooting strength of apple trees was considerably smaller than the uprooting strength of forest trees reported in previous studies. However, the windthrow resistance of the apple trees with respect to the critical wind velocity was estimated to be sufficient despite their low uprooting strength because of their small height. Young trees should be supported with wooden posts for a few years after grafting so that they acquire sufficient windthrow resistance.SpringerJournal Articleapplication/pdfhttp://hdl.handle.net/2115/32604https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/32604/1/koizumi.pdf1435-02111611-4663AA11200007Journal of Wood Science54110152008-01enginfo:doi/10.1007/s10086-007-0907-7The original publication is available at www.springerlink.comauthor