Poor performance of Douglas-fir (Pseudotsuga menziesii) plantations established in 1987 has occurred in southwestern British Columbia.  Affected sites were planted with one-year old container stock that exhibited some root die-back in the nursery.  A study was initiated in 1991 to assess Cylindrocarpon  and Fusarium root infection in planted and naturally regenerating (natural) Douglas-fir seedlings from seven affected plantations.  Percent of seedlings harbouring Cylindrocarpon spp. and percent root colonization was significantly greater for planted seedlings compared to natural seedlings.  A significant linear trend in Cylindrocarpon root colonization was observed for planted seedlings with colonization levels being highest for roots closest to the remnants of the root plug and decreasing at distances greater than 10 cm from that region.  This trend in Cylindrocarpon colonization was not observed for natural seedlings.  Cylindrocarpon destructans var. destructans and C. cylindroides var.  cylindroides were only species isolated fro, planted and natural conifer seedlings.  For most sites, percent of seedlings harbouring Fusarium spp. and percent Fusarium root colonization were less than for Cylindrocarpon.  Recovery of Fusarium spp. from seedlings and root colonization levels were not significantly different for planted and natural seedlings from all sites.
 
 
 
 

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