Canadian Forest Service Publications

Biological control of red alder (Alnus rubra) with indigenous pathogenic Ascomycotina. 1996. Dorworth, C.E.; Macey, D.E.; Sieber, T.N.; Woods, T.A.D. Canadian Journal of Plant Pathology 18(4): 315-324.

Year: 1996

Issued by: Pacific Forestry Centre

Catalog ID: 4726

Language: English

CFS Availability: PDF (request by e-mail)

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Red alder (Alnus rubra) is a valuable timber tree on 10-20% of forested lands in Pacific Coastal North America and is an undesirable competitor of planted conifers, to a greater or lesser extent, on much of the remainder. A biological control strategy to manage red alder was developed for use in environmentally sensitive areas in which pesticides are prohibited by law, and as a complement to extant weed control measures. Red alder trees within a typical west coast forest were inoculated with pathogen-colonized wood dowels inserted into stem punctures, using technology designated PFC-MYCOCHARGE®. Each of 11 blocks of 30 trees (6 per diameter class, 0.5 cm to approximately 50 cm diam) was inoculated with 1 of 11 isolates of seven species of Ascomycotina previously isolated from red alder in British Columbia. A 12th block of 30 trees was treated with noncolonized dowels and designated the control block. A single isolate of Nectria ditissima (PFC-082/ATCC 74260; U.S. Pat. Off. 5 340 578) proved worthy of commercial development by virtue of nearly 100% inoculation success, notable alder tissue damage, and reduction in general health of inoculated trees. A significant relationship between pathogen species and mortality was not recorded during the limited period of the test. N. ditissima PFC-082 did not reproduce on the trees and was soon displaced by secondary organisms, so the danger of unwanted dispersion of the pathogen was nil. The PFC-MYCOCHARGE® strategy is recommended for commercial development as a component of forest management plans for implementation during pre-commercial stand improvement activity.