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• 1. [Article] Effects of a 2-year fallow period on soil populations of Fusarium, Trichoderma and Pythium species after incorporating corn plant residues : USDA Forest Service Nursery, Coeur d'Alene, Idaho

  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 ...

  Citation × Citation Citation Abstract Copy Title: Effects of a 2-year fallow period on soil populations of Fusarium, Trichoderma and Pythium species after incorporating corn plant residues : USDA Forest Service Nursery, Coeur d'Alene, Idaho Author: United States. Forest Service. Northern Region, James, Robert L., United States. Forest Health Protection 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 did not decrease over the fallow period and were at sufficient levels after two years to be of concern from a disease potential standpoint. Populations of Pythium were fairly low throughout the monitoring period. Trichoderma populations remained high, but were probably not sufficient to ameliorate Fusarium disease potential. Fusarium spp. readily colonized soil organic matter particularly roots of the previous conifer seedling crop; these fungi also frequently colonized corn organic debris. Fusarium oxysporum was the major potential pathogen colonizing soil and organic matter. When a corn cover/green manure crop is produced within fields destined for conifer seedling production, these fields will require soil fumigation prior to sowing seedling crops to reduce risk of Fusarium-associated diseases. Title: Effects of a 2-year fallow period on soil populations of Fusarium, Trichoderma and Pythium species after incorporating corn plant residues : USDA Forest Service Nursery, Coeur d'Alene, Idaho Author: United States. Forest Service. Northern Region, James, Robert L., United States. Forest Health Protection 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 did not decrease over the fallow period and were at sufficient levels after two years to be of concern from a disease potential standpoint. Populations of Pythium were fairly low throughout the monitoring period. Trichoderma populations remained high, but were probably not sufficient to ameliorate Fusarium disease potential. Fusarium spp. readily colonized soil organic matter particularly roots of the previous conifer seedling crop; these fungi also frequently colonized corn organic debris. Fusarium oxysporum was the major potential pathogen colonizing soil and organic matter. When a corn cover/green manure crop is produced within fields destined for conifer seedling production, these fields will require soil fumigation prior to sowing seedling crops to reduce risk of Fusarium-associated diseases. Close

• 2. [Article] Effects of preplant soil treatments on Fusarium and Trichoderma populations and fungal root colonization of 2-0 nondiseased western white pine seedlings - USDA Forest Service Nursery, Coeur d'Alene, Idaho

  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 ...

  Citation × Citation Citation Abstract Copy Title: Effects of preplant soil treatments on Fusarium and Trichoderma populations and fungal root colonization of 2-0 nondiseased western white pine seedlings - USDA Forest Service Nursery, Coeur d'Alene, Idaho Author: United States. Forest Service. Northern Region, James, Robert L., United States. Forest Health Protection 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 fumigation with dazomet, bare fallowing with periodic cultivation, steam treatment, fallowing with amendments of Trichoderma harzianum biocontrol agents (BioTrek® and University of Idaho isolates [UI]), and incorporation of two cultivars of winter Brassica cover crops followed by biocontrol amendments (UI). Soil Fusarium populations were significantly reduced by dazomet fumigation; fallowing with biocontrol amendments and incorporating winter mustard crops with biocontrol amendments resulted in significantly higher Fusarium populations. Trichoderma populations were significantly decreased by dazomet fumigation, bare fallowing and steam treatment. Incorporation of Brassica crops did not significantly affect soli Trichoderma populations. Level of Fusarium root colonization was significantly reduced by dazomet fumigation and steam treatment. High levels of root colonization by rhizosphere-inhabiting isolates of Cylindrocarpon were common in some treatments. Assaying root colonization by selected fungi may supplement other parameters to evaluate effectiveness of soil treatments implemented to reduce pathogen populations and improve conifer seedling production. Title: Effects of preplant soil treatments on Fusarium and Trichoderma populations and fungal root colonization of 2-0 nondiseased western white pine seedlings - USDA Forest Service Nursery, Coeur d'Alene, Idaho Author: United States. Forest Service. Northern Region, James, Robert L., United States. Forest Health Protection 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 fumigation with dazomet, bare fallowing with periodic cultivation, steam treatment, fallowing with amendments of Trichoderma harzianum biocontrol agents (BioTrek® and University of Idaho isolates [UI]), and incorporation of two cultivars of winter Brassica cover crops followed by biocontrol amendments (UI). Soil Fusarium populations were significantly reduced by dazomet fumigation; fallowing with biocontrol amendments and incorporating winter mustard crops with biocontrol amendments resulted in significantly higher Fusarium populations. Trichoderma populations were significantly decreased by dazomet fumigation, bare fallowing and steam treatment. Incorporation of Brassica crops did not significantly affect soli Trichoderma populations. Level of Fusarium root colonization was significantly reduced by dazomet fumigation and steam treatment. High levels of root colonization by rhizosphere-inhabiting isolates of Cylindrocarpon were common in some treatments. Assaying root colonization by selected fungi may supplement other parameters to evaluate effectiveness of soil treatments implemented to reduce pathogen populations and improve conifer seedling production. Close

• 3. [Article] Meria needlecast of western larch seedlings at the USDA Forest Service Nursery, Coeur d'Alene, Idaho

  Needlecast caused by Meria laricis caused serious losses of 2-0 bareroot western larch during 1983 at the USDA Forest Service Nursery, Coeur d'Alene, Idaho. Cool, wet weather throughout the spring and ...

  Citation × Citation Citation Abstract Copy Title: Meria needlecast of western larch seedlings at the USDA Forest Service Nursery, Coeur d'Alene, Idaho Author: United States. Forest Service. Northern Region, James, Robert L. Needlecast caused by Meria laricis caused serious losses of 2-0 bareroot western larch during 1983 at the USDA Forest Service Nursery, Coeur d'Alene, Idaho. Cool, wet weather throughout the spring and summer of 1983 was ideal for disease buildup and spread. Control attempts with fungicides were largely unsuccessful because of the conducive weather conditions and high inoculum levels. The disease was also found on containerized larch, although serious damage was not evident. The 1984 bareroot crop had high levels of infection in the spring, but consistent fungicide treatments and warm, dry summer weather resulted in no detectable disease by the fall. Title: Meria needlecast of western larch seedlings at the USDA Forest Service Nursery, Coeur d'Alene, Idaho Author: United States. Forest Service. Northern Region, James, Robert L. Needlecast caused by Meria laricis caused serious losses of 2-0 bareroot western larch during 1983 at the USDA Forest Service Nursery, Coeur d'Alene, Idaho. Cool, wet weather throughout the spring and summer of 1983 was ideal for disease buildup and spread. Control attempts with fungicides were largely unsuccessful because of the conducive weather conditions and high inoculum levels. The disease was also found on containerized larch, although serious damage was not evident. The 1984 bareroot crop had high levels of infection in the spring, but consistent fungicide treatments and warm, dry summer weather resulted in no detectable disease by the fall. Close

• 4. [Article] Effects of radio frequency waves on fungal colonization of styroblock containers

  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 ...

  Citation × Citation Citation Abstract Copy Title: Effects of radio frequency waves on fungal colonization of styroblock containers Author: United States. Forest Service. Northern Region, Trent, Andy, James, Robert L., United States. Forest Health Protection 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 containers was evaluated. RFs were effective only on containers that had been wetted in warm water prior to treatment. RFs were not effective on dry containers. Fusarium proliferatum was the most commonly encountered potentially-pathogenic fungus isolated from containers. Seven other species of Fusarium and two species of Cylindrocaipon were also isolated from containers. Common fungal saprophytes on containers included Trichoderma and Penicillium spp. Although wet RF treatment was as effective as hot water immersion, such treatments may be much more expensive due to high costs of RF equipment. Title: Effects of radio frequency waves on fungal colonization of styroblock containers Author: United States. Forest Service. Northern Region, Trent, Andy, James, Robert L., United States. Forest Health Protection 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 containers was evaluated. RFs were effective only on containers that had been wetted in warm water prior to treatment. RFs were not effective on dry containers. Fusarium proliferatum was the most commonly encountered potentially-pathogenic fungus isolated from containers. Seven other species of Fusarium and two species of Cylindrocaipon were also isolated from containers. Common fungal saprophytes on containers included Trichoderma and Penicillium spp. Although wet RF treatment was as effective as hot water immersion, such treatments may be much more expensive due to high costs of RF equipment. Close