Canadian Forest Service Publications

Year: 1992

Available from: Pacific Forestry Centre

Catalog ID: 3258

Language: English

CFS Availability: Order paper copy (free)

Abstract

Chondrostereum purpureum, the causal agent of silver leaf disease of orchard crops, is also being evaluated for its beneficial potential as a mycoherbicide for red alder (Alnus rubra Bong.), a major competitor in conifer plantations throughout British Columbia (B.C.). Three plots consisting of at least 60 saplings were selected near French Beach, Vancouver Island, B.C. for field testing. Twenty trees in each plot were girdled with a knife at breast height (130 cm) and ten of the girdling wounds were subsequently inoculated with mycelia of C. purpureum and sealed with Parafilm (R). The ten control wounds received only agar before being sealed. Eight months after inoculation, downward necrosis (DN) and percent dieback (PD) were recorded and subjected to analysis of variance. Mean DN and PD were 4.0 cm and 27%, respectively. This was significantly different than the lack of response in the controls both measurements; control trees completely recovered from the girdling effects. Girdling stress also triggered attack from endophytic fungi, particularly Melanconium sp., on the main stems and branches of trees inoculated with C. purpureum. The results indicate that C. purpureum has potential as a mycoherbicide for red alder, either alone or in combination predisposing mechanical, environmental, or chemical stresses or endophytes.