Description:
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
50 percent. Cells stored for several months still contained high levels of Fusarium inoculum. Most Fusarium
inoculum was concentrated at or near the bottom of cells. Cells with high Fusarium levels had corresponding low
levels of Trichoderma and vice versa. Ability of the Fusarium isolates from cells to cause seedling diseases is
unknown, but Fusarium-caused disease is common at the nursery.