CAMBIUM DESTRUCTION IN CONIFERS CAUSED BY PINEWOOD NEMATODES

  • 1 July 1986
    • journal article
    • research article
    • Vol. 18  (3) , 398-402
Abstract
Percentage and rate of mortality in 2-4-year-old conifers [Pinus spp.] depended upon the numbers of pinewood nematodes Bursaphelenchus xylophilus inoculated into their stems. In addition, percentage of conifer mortality was greater for spring inoculations when cambial activity was greater than for late summer and fall inoculations. Gross and histological examination of stems revealed destruction of the cambial layer, including fusiform and ray iniitals and their derivatives. These data suggest that cambial and ray destruction causes tree death through blockage of tracheids by gas, oleoresin, or metabolites from dying ray tissues.