Influence of Disease Management Strategies on the Production of White Spruce in a Forest Tree Nursery

Washington D.C.

1989

S. 1006-1013

1 Abb., 4 Tab., 24 Lit. Ang.

Bandaufführung

64482

In a Wisconsin forest tree nursery dazomet, captan, thiram, captan-thiram combination, or silica sand did not reduce populations of three soilborne fungi. Preemergence 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%) and 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 the seedings, respectively. Seedling mortality from May 18 to September 23, 1986, ranged from 28% inthe dazomet plots to 61% in nontreated plots. At the end of the first growing season, plots treated with dazomet had significantly more seedlings than any other treatment. The incidence of stunted seedlings was greatest in plots treated with dazomet and lest when seed was covered with silica sand. Silica sand or thiram treatments produced seedlings with the greatest total dry weights.