Visible versus actual incidence of Armillaria root disease in juvenile coniferous stands in the southern interior of British Columbia

The relationship between aboveground symptoms and belowground incidence of Armillaria ostoyae (Romagn.) Herink on conifers in 13- to 24-year-old stands was investigated at five sites in each of the dry, moist, and wet climatic regions in the Nelson forest region, British Columbia. All trees >1.3 m in height in 0.01-ha circular plots centred on a tree killed fewer than two or more than five years previously or located where there were no symptomatic trees were removed from the soil by an excavator. The location and host response at each A. ostoyae lesion on root systems were recorded. Significant differences in belowground incidence were seen among climatic regions and plot types, with distance from the centre of plots, and between planted and naturally regenerated trees. Belowground inci - dence was related to the percentage of putatively colonized stumps within and adjacent to plots. There were significant differences among climatic regions in the intensity of infection, host reaction to infection, and percentage of diseased trees showing aboveground symptoms. These results have implications for interpreting results of surveys for Armillaria root disease in juvenile stands and for tending of such stands.

[1]  J. McLaughlin,et al.  Distribution, hosts, and site relationships of Armillaria spp. in central and southern Ontario , 2001 .

[2]  J. Dettman,et al.  The population structure of Armillaria ostoyae in the southern interior of British Columbia , 2001 .

[3]  A. Nemec,et al.  Effects of selective cutting on the epidemiology of armillaria root disease in the southern interior of British Columbia , 2001 .

[4]  P. Rosso,et al.  Tree vigour and the susceptibility of Douglas fir to Armillaria root disease. , 1998 .

[5]  C. Dubetz,et al.  DNA diagnostic for Armillaria species in British Columbia: within and between species variation in the IGS-1 and IGS-2 regions. , 1998 .

[6]  Z. Punja,et al.  Incidence of Armillaria species in precommercial thinning stumps and spread of Armillaria ostoyae to adjacent Douglas-fir trees , 1997 .

[7]  R. Irwin,et al.  Effect of Northwestern Ontario Forest Ecosystem Classification treatment units on the infection levels of Armillaria in black spruce plantations. , 1996 .

[8]  D. Morrison,et al.  Silvicultural management of armillaria root disease in western Canadian forests , 1996 .

[9]  T.-T. Chang.  Survival of Phellinus noxius in soil and in the roots of dead host plants , 1996 .

[10]  D. J. Morrison,et al.  Common Tree Diseases of British Columbia , 1996 .

[11]  P. M. Hall,et al.  Forest health research needs in British Columbia , 1995 .

[12]  B. Kamp.  The spatial distribution of Armillaria root disease in an uneven-aged, spatially clumped Douglas-fir stand , 1995 .

[13]  G. Filip,et al.  Precommercial thinning in Pseudotsuga, Tsuga, and Abies stands affected by armillaria root disease: 10-year results , 1995 .

[14]  A. Woods.  The behaviour and impacts of Armillaria ostoyae in mature stands and plantations in the Shuswap region of British Columbia , 1994 .

[15]  C. Shaw,et al.  Infection of Ponderosa Pine Trees by Armillaria ostoyae: Residual lnoculum versus Contagion , 1993 .

[16]  W. Livingston.  Armillaria ostoyae in young spruce plantations. , 1990 .

[17]  G. Hope,et al.  A guide to site identification and interpretation for the Kamloops Forest Region. , 1990 .

[18]  A. R. Stage,et al.  User's manual for western root diseases model / , 1990 .

[19]  D. Hosmer,et al.  Applied Logistic Regression , 1991 .

[20]  W. Bloomberg,et al.  Relationship of growth reduction in Douglas-fir to infection by Armillaria root disease in Southeastern British Columbia , 1989 .

[21]  R. D. Whitney.  Armillaria Root Rot Damage in Softwood Plantations in Ontario , 1988 .

[22]  D. Chu,et al.  Species of Armillaria in British Columbia. , 1985 .

[23]  C. G. Shaw,et al.  Armillaria root rot: the puzzle is being solved. , 1985 .

[24]  J. Kyncl,et al.  A tree‐ring study of Norway spruce infected with the wood‐destroying fungus Armillaria mellea , 1983 .

[25]  K. Reynolds,et al.  Estimating probability of intertree root contact in second-growth Douglas-fir , 1982 .

[26]  W. Bloomberg,et al.  Estimating the total extent of Phellinusweirii root rot centers using above- and below-ground disease indicators , 1981 .

[27]  C. Shaw.  Characteristics of Armillaria mellea on pine (Pinus ponderosa) root systems in expanding centers of root rot. , 1980 .

[28]  Pritam Singh,et al.  Armillaria root rot in seeded and planted areas in Newfoundland , 1973 .

[29]  R. G. McMinn,et al.  CHARACTERISTICS OF DOUGLAS-FIR ROOT SYSTEMS , 1963 .