Whitebark pine, Pinus albicaulis Engelm. is an important but declining high-elevation tree species in western forests. Regeneration of this species has been difficult and the impact of cone and seed insects unknown. Seven sites selected from the geographical range of whitebark pine in Idaho, Montana, Washington, Oregon, and California were...
Tests were conducted at the USDA Forest Service Nursery, Coeur d'Alene, Idaho to evaluate effectiveness of spring fumigation with dazomet to improve survival and performance of Douglas-fir and western white pine transplants. Spring fumigation greatly reduced populations of potentially pathogenic Fusarium and Pythium spp. Disease levels of container (plug+1) and...
Soil in Field 2 at the USDA Forest Service Nursery, Coeur d'Alene, Idaho was assayed six times over a 2-year fallow period for potentially pathogenic Fusarium and Pythium spp. following incorporation of a corn cover/green manure crop. Populations of potentially disease-antagonistic Trichoderma spp. were also assayed. Soil populations of Fusarium...
We analyzed the effects of pathogens and insects on forest succession in the absence of
fire or management, addressing a number of related questions:
1. What is the rate of change in such forests?
2. How significant are the roles of pathogens and insects in the forest change?
3. How...
Thirty-three isolates of Fusarium acuminatum obtained from inland Pacific Northwest forest nurseries were tested for their pathogenicity on young Douglas-fir germinants under controlled laboratory conditions. Tested isolates were from forest nursery soil, roots of healthy-appearing and diseased conifer seedlings, Styrofoam and hard plastic containers, conifer seeds, 411 and adult fungus...
Forty-seven isolates of Fusarium solani obtained from the roots of diseased and healthy conifer seedlings and forest nursery soil were tested for pathogenicity on young Douglas-fir germinants under controlled laboratory conditions. Isolate virulence varied widely; a few were highly virulent whereas many were classified as non-pathogenic. Isolates from the roots...
Investigations were conducted from 1998-
2000 at the Potlatch Corporation's
Cherrylane Seed Orchard near Lewiston,
Idaho to evaluate presence and extent of
potentially pathogenic fungi on roots of
diseased stock and within the soil in current
and proposed plantation sites. The most
common group of pathogens encountered
was Fusarium spp.;...
Fungal pathogens tend to accumulate within styroblock containers, which are reused to produce successive crops of container-grown seedlings. Most nurseries treat reused containers by immersing them in hot water for varying time periods. The efficacy of radio frequency waves (RFs) to reduce levels of selected groups of fungi within styroblock...
Preplant soil treatments were implemented to determine effects on populations of potentiallypathogenic Fusarium and potentially disease-suppressive Trichoderma spp. as well as root colonization by these and other selected fungi on healthy-appearing, bare root 2-0 western white pine seedlings at the USDA Forest Service Nursery, Coeur d'Alene, Idaho. Soil treatments included...
A preliminary evaluation of the biological control formulation of Trichoderma harzianum marketed as BioTrek® was conducted on bareroot Douglasfir and western white pine seedlings at the USDA Forest Service Nursery, Coeur d'Alene, Idaho. The biocontrol material was applied topically on seed shortly after sowing and comparisons made between treated and...
Tree damage following dust abatement/road
stabilization treatment was evaluated on 12.5
miles of the Selway River Road, Nez Perce
National Forest. Calcium chloride was applied in
June of 2000, mostly at a rate of 51b/yd2 (18,600
lb./acre) or 6.9 lb/yd 2 (25,700 lb/acre). 1,189
trees up to 30 feet from...
Healthy-appearing 1-0 ponderosa and lodgepole pine seedlings were assayed for root infection and colonization by potentially-pathogenic fungi following pre-sowing soil treatments which included methyl bromide/chloropicrin (MBC) fumigation, fallowing with or/without periodic cultivation, and amending soil with mushroom composts or undecomposed sawdust. Levels of root colonization by Fusarium spp. on both...
The unusually large amount of ice, snow,
and wind-damaged trees that occurred
during the winter of 1996-97 provided prime
habitat for populations of the Douglas-fir
beetle (DFB) (Dendroctonus pseudotsugae)
to build to epidemic numbers. Beetles
emerged during the spring and summer of
1998, attacking hundreds of thousands of
standing Douglas-fir...
Whitebark pine is an important reforestation species in the northern Rocky Mountains for enhancement of wildlife habitat. Production of container-grown whitebark pine seedlings at the USDA Forest Service Nursery in Coeur d'Alene, Idaho has been increasing the past several years. Diseases continue to be an important limiting factor in seedling...
The objective of this report is to describe the current increase in Douglas-fir tussock moth (Orgyia pseudotsugata McDunnough) activity in northern Idaho and Montana. The report also relates current conditions to historical and future trends and larger scale increasing tussock moth activity in surrounding western states.