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...
Three hundred fifty Leach pine cells used to grow containerized conifer seedlings at the USDA Forest Service Nursery in Coeur d'Alene, Idaho, were sampled for Fusarium and Trichoderma colonization. Cells were either sampled prior to or after cleaning. Cleaning reduced Fusarium colonization from 86 percent of the cells to about...
Isolates of Botrytis cinerea from containerized conifer seedlings from two
nurseries in the Northern Rocky Mountains were exposed to the
dicarboximide fungicides vinclozolin and iprodione and the chlorinated
nitroaniline fungicide dicloran to evaluate occurrence and characteristics
of resistant strains. The isolates were grown on test media prepared by
incorporating the...
Investigations of containerized conifer seedling root diseases at the Champion Timberlands Nursery revealed that Fusarium oxysporum was most commonly isolated from seed, seedling roots, and styroblock containers. Amount of seed infection varied widely among the seedlots tested, but was usually below 5 percent. Runningwater rinses did not reduce amounts of...
Three stands along Benton Creek within the Priest River Experimental Forest, Idaho, were surveyed for diseases using previously established timber inventory plots and sample trees. These surveys provided information to aid in formation of silvicultural prescriptions by CEFES (Continuing Education in Forest Ecology and Silviculture) students. Diseases were quantified at...
Treating styroblock containers in hot water (68°C) with a very dilute bleach and detergent solution effectively reduced populations of Fusarium and Cylindrocarpon spp., two potential root pathogens of containerized conifer seedlings. However, the treatment did not significantly reduce levels of Phoma (another potential pathogen) nor saprophytic Penicillium and Alternaria spp....
Investigations of containerized western white pine, western larch, and Douglas-fir seedlings at the Western Forest Systems Nursery in Lewiston, Idaho, revealed that many seedlings were colonized with Fusarium oxysporum although they lacked severe disease symptoms. White pine seedlings were also infected with Pythium spp., probably as a result of sowing...
Containerized western larch, Douglas-fir, grand fir, subalpine fir, and ponderosa pine seedlings which displayed disease symptoms were sampled for presence of Fusarium spp. Seedlings from 33 seedlots within the Northern Region were sampled. Major types of diseases included post-emergence damping-off, root disease (late damping-off), and cotyledon blight. Fusarium oxysporum was...
Isolates of Fusarium oxysporum, F. acuminatum, and F. sambucinum obtained from peat-vermiculite soil mixes were tested for pathogenicity on ponderosa pine, lodgepole pine, western larch, and blue spruce containerized seedlings and on germination of Scots pine and blue spruce seed. Ponderosa pine seedling were the least susceptible to killing by...
This book provides an illustrated guide to the identification and management of fungi, insects, and abiotic conditions that cause problems in Northwest bareroot conifer nurseries. A key to nursery pests offers initial guidance in identification. Separate chapters address individual pests with details on recognition, damage cycle, and management practices to...