Canadian Forest Service Publications

Dothistroma needle blight on western white pine in British Columbia. 2011. Hunt, R.S.; Roke, G.; Cleary, M.; Carlson, M.; Berger, V. Canadian Plant Disease Survey 91: 158-167.

Year: 2011

Issued by: Pacific Forestry Centre

Catalog ID: 32734

Language: English

Availability: PDF (download)

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Dothistroma needle blight (Dothistroma septosporum (Dorog.) Morelet), also known as red band needle blight, can be a devastating disease of pines (Barnes et al. 2005; Woods et al. 2005). Needles of all ages are affected, usually in the lower portion of the crown, but in more severe cases the disease can cause total defoliation and mortality. This is the case with the current D. septosporum outbreak in northwestern British Columbia (BC) where it is causing unprecedented mortality in plantations and mature stands of lodgepole pine (P. contorta var. latifolia Dougl. ex. Loud.) (Woods et al. 2005). Severe defoliation caused by D. septosporum has been reported in western white pine (P. monticola D. Don) in Idaho (Shaw and Leaphart 1960). However, in BC the disease was not reported to cause severe defoliation on P. monticol until 1982 when it caused up to 80% discoloration and defoliation in 15-30 year-old stands of nearly pure white pine in southeastern BC [Forest Insect and Disease Conditions (FIDS) 1982-1990]. In 1982, at the most severely affected location near Nakusp, a permanent sample plot was established by FIDS and examined for 8 years. Although severity varied annually (between 56 and 82% of needles infected), the disease was nonetheless present each year and caused substantial reduction in height and diameter (Unger and Vallentgoed 1990). Mortality resulting from repeated severe infections was reported for only one tree during the 8-year assessment (FIDS 1982-1990).