Influence of disease management strategies on the production of white spruce in a forest tree nursery

In a Wisconsin forest Picea glauca nursery dazomet, captan, thiram, captan-thiram combination, or silica sand did not reduce populations of 3 soilborne fungi. Pre-emergence mortality was greatest in nontreated plots (56%) and least in plots treated with dazomet (46%). Nontreated plots had the most post-emergence damping off (15%), silica sand the least (3%). Rhizoctonia solani (AG-1) was isolated from 52% of damped-off seedlings collected while Pythium spp., Fusarium spp. and Cylindrocladium spp. were recovered from 24%, 23%, and 1% of seedlings, respectively. Seedling mortality from May 18 to September 23, 1986, ranged from 28% in the dazomet plots to 61% in nontreated plots. At the end of the 1st growing season, plots treated with dazomet had significantly more seedlings than any other treatment. -from Authors