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...
Six fungicides were evaluated to control Botrytis blight of western 41 larch in seedbeds at the Coeur d'Alene Nursery. Fungicides were applied at biweekly intervals during the spring of 1982; test seedlings were inoculated with spores of B. cinerea twice during the evaluation period. Seedling mortality and height were recorded...
Causes of mortality of containerized western larch seedlings at the Champion Timberlands Nursery, Plains, Montana, were investigated. Seedlings were rated for disease severity based on extent of foliar decline symptoms and fungal isolations made from their roots. Isolations were also made from selected larch seed. Consistent associations between root colonization...
Five fungicides were evaluated to control Botrytis blight of containerized western larch seedlings at the Champion Timberlands Nursery, Plains, MT. Fungicides were applied at biweekly intervals before and after seedling inoculation with Botrytis. Vinclozolin (Ornalin®) caused severe phytotoxicity to seedlings, resulting in enhanced mortality and premature needle loss. Captan and...
Root disease of 2-0 western white pine seedlings occurred at the Coeur d'Alene Nursery in 1982 within seedbeds fumigated with methyl bromide and chloropicrin. Although losses were not substantial, there were several groups of dead seedlings within affected seedbeds. Fusarium oxysporum was most often isolated from diseased roots. Other Fusarium...
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...
Mortality of western white pine transplants used to assess resistance to blister rust at the USDA Forest Service Nursery in Coeur d'Alene, Idaho was likely due to extensive root infection by Pythiva app. Severity of foliar symptom production was significantly correlated with extent of root system colonization by these fungi....
Mortality of containerized western white pine seedlings outplanted on the Bonners Ferry Ranger District, Idaho Panhandle National Forests, was probably due to extensive root infection by Fusarium oxysporum. Diseased seedlings had chlorotic foliage, needle tip dieback, and severe twisting of the needles that indicated wilting. Most root tips of diseased...