Comment-Using spatial and temporal patterns of Armillaria root disease to formulate management recommendations for Ontario's black spruce (Picea mariana) seed orchards

1998 ◽  
Vol 28 (1) ◽  
pp. 154-158 ◽  
Author(s):  
G Hughes ◽  
L V Madden
Keyword(s):  
Picea Mariana ◽  
Black Spruce ◽  
Temporal Patterns ◽  
Root Disease ◽  
Spatial And Temporal Patterns ◽  
Seed Orchards ◽  
Armillaria Root Disease ◽  
Management Recommendations

Using spatial and temporal patterns of Armillaria root disease to formulate management recommendations for Ontario's black spruce (Piceamariana) seed orchards

1996 ◽  
Vol 26 (2) ◽  
pp. 298-305 ◽  
Author(s):  
J.N. Bruhn ◽  
J.D. Mihail ◽  
T.R. Meyer
Keyword(s):  
Management Practices ◽  
Black Spruce ◽  
Root Disease ◽  
Forest Land ◽  
Spatial And Temporal Patterns ◽  
Seed Orchards ◽  
Disease Mortality ◽  
Armillaria Root Disease ◽  
Management Recommendations ◽  
Logistic Functions

Between 1982 and 1989, 22 black spruce (Piceamariana (Mill.) BSP) seed orchards were established on cleared jack pine (Pinusbanksiana Lamb.) forest land in northwest Ontario. These orchards were located on stressful sites for black spruce to hasten seed production. Mortality caused by Armillariaostoyae (Romagn.) Herink was observed in most of these orchards within 3 years of establishment. This study was initiated to quantitatively describe the temporal progress and spatial patterns of Armillaria root disease mortality in five representative orchards, to determine future operational management implications. In the four orchards where epidemics developed, temporal disease progress was nonlinear and was better described by the monomolecular function than by the Gompertz or logistic functions. Monomolecular rates of disease increase were 0.0062–0.0346. Applying these rates, we estimated that cumulative Armillaria root disease mortality will be 9–41% and 25–79%, at 20 and 50 years after planting, respectively. Armillaria root disease mortality was spatially aggregated in all four orchards. Trees adjacent to Armillaria-killed trees had an increased probability of mortality from Armillaria root disease. Successive epidemics may develop in these orchards; their timing and severity will be affected by orchard management practices. Measures of spruce family performance in these orchards are compromised by the aggregated distributions of different A. ostoyae genets and the root disease they cause.

Effects of stem injections of gibberellin A4/7 and paclobutrazol on sex expression and the within-crown distribution of seed and pollen cones in black spruce (Picea mariana)

1998 ◽  
Vol 28 (5) ◽  
pp. 641-651 ◽  
Author(s):  
Ronald F Smith
Keyword(s):  
Picea Mariana ◽  
Black Spruce ◽  
Sex Expression ◽  
Bud Burst ◽  
Seed Orchards ◽  
Adjunct Treatment ◽  
Cone Production ◽  
Pollen Cone ◽  
Dose Dependent ◽  
Vegetative Bud

Two experiments in black spruce (Picea mariana (Mill.) BSP) seedling seed orchards were established to determine if a stem injection of paclobutrazol (2RS,3RS)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1H-1,2,4-triazol-1-yl) could be used as an adjunct treatment to increase the efficacy of stem injections of gibberellins A4 and A7 (GA4/7). Trees received a single injection of GA4/7 and (or) paclobutrazol shortly after vegetative bud burst. There was a dose-dependent but nonlinear increase in the production of cones of both sexes in response to stem injections of either GA4/7 or paclobutrazol. The optimum rate of GA4/7 for stimulating pollen-cone production was 3.3 mg, whereas the most seed cones were induced on trees receiving 11 mg. The sex ratio (number of seed cones/number of pollen cones) increased with the rate of GA4/7 applied. Injecting paclobutrazol also promoted cones of both sexes equally, resulting in sex ratios comparable with that of the control trees. Treatments did not affect the total numbers of buds (vegetative, latent, and cone) produced. Seed- and pollen-cone buds occurred in positions that would have otherwise developed vegetatively and become latent, respectively. The mechanisms whereby paclobutrazol could affect flowering in black spruce are discussed. The use of paclobutrazol as an adjunct to GA4/7 treatments in black spruce seedling seed orchards appears effective, practical, and safe.

Armillariaostoyae in young spruce plantations

1990 ◽  
Vol 20 (11) ◽  
pp. 1773-1778 ◽  
Author(s):  
William H. Livingston
Keyword(s):  
Black Spruce ◽  
Lateral Roots ◽  
White Spruce ◽  
Root Disease ◽  
Stem Height ◽  
Conifer Seedlings ◽  
Armillaria Root Disease ◽  
Root Collar

Black spruce (Piceamariana (Mill.) B.S.P.) and white spruce (P. glauca (Moench) Voss) plantations, 4–10 years old, were examined for Armillaria root disease. The disease was found in 89% of 27 sample locations, and up to 2% of the trees were recently killed. Armillariaostoyae (Romagn.) Herink was the cause of the disease. Spruce show little reduction in stem height and diameter prior to being killed by the fungus. Lethal infections of A. ostoyae develop primarily at the root collar and are associated with root deformities and small diameters of lateral roots. Root deformities, frequently associated with growing conifer seedlings in containers, are hypothesized to predispose planted spruce to Armillaria root disease.

Effects of Armillaria root disease on the growth of Picea mariana trees in the boreal plains of central Canada

2012 ◽  
Vol 266 ◽  
pp. 1-10 ◽  
Author(s):  
A.R. Westwood ◽  
F. Conciatori ◽  
J.C. Tardif ◽  
K. Knowles
Keyword(s):  
Picea Mariana ◽  
Root Disease ◽  
Boreal Plains ◽  
Central Canada ◽  
Armillaria Root Disease

Comparison of Armillaria root disease on burned and unburned, harvested sites in Ontario

2005 ◽  
Vol 81 (1) ◽  
pp. 56-60 ◽  
Author(s):  
R D Whitney ◽  
R N Irwin
Keyword(s):  
Root Rot ◽  
Black Spruce ◽  
Jack Pine ◽  
Control Area ◽  
Root Disease ◽  
The Other ◽  
Balsam Fir ◽  
Burned Area ◽  
Armillaria Root Disease ◽  
Burned Site

Averages of 10, 10, 0 and 4% of white spruce, black spruce, balsam fir and jack pine saplings were killed by Armillaria Root Disease (ARD), after 10 years following planting around 50 infected stumps that had been prescribed burned. Comparable averages on an unburned control area of 8, 8, 0 and 6% were not significantly different from the burned area. ARD did not occur in any trees planted adjacent to five deeply burned stumps. However, no statistically significant relationship was found between ARD and intensity of burn on stumps. Significantly (p = .05) fewer balsam fir saplings were killed by ARD than of either white or black spruce. Jack pine heights were significantly greater (p = .05) than those of the other species on both locations after10 years, and on the unburned site after 17 years (experimental trees on the burned site were inadvertently cut during a silvicultural thinning in the year prior to measurements in the 17th year). Balsam fir heights were significantly less (p = .05) than those of the other three species on both sites after 10 years, and after 17 years on the unburned site. Key words: Root rot, Armillaria, burning, height growth, spruce, balsam fir, jack pine

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