Eleven series of untreated posts, 33 series of nonpressuretreated posts, and 13 series of pressure-treated posts remain in test. Series in which all posts have failed now number 34 for untreated, and 18 for nonpressure-treated. Causes of failures since 1949 were: fungi, 77 per cent of failures; fungi and termites,...
Correlation was sought between abundance of mycorrhizae on
Douglas-fir seedlings and their survival in field plantations.
One possible indication of dormancy desirable for lifting from
nursery beds could be the varying seasonal abundance of ectotrophic
mycorrhizae on roots of seedlings. No direct correlation between percentage
of mycorrhizae and survival in...
The effect of lifting Douglas-fir seedlings from the nursery bed
and replanting them, either immediately or after storage at 2 C for
periods up to six weeks, was investigated through a series of experiments
conducted in controlled-environment chambers and under field
conditions. Seedlings lifted prior to December, or after buds...