See the definition 1a and 1b, Mick. This is a copy/paste from the Webster's Dictionary website.
Definition of inoculate
inoculated; inoculating
transitive verb
1 a : to introduce a microorganism into; inoculate mice with anthrax; beans inoculated with nitrogen-fixing bacteria
b : to introduce (something, such as a microorganism) into a suitable situation for growth
c : to introduce immunologically active material (such as an antibody or antigen) into especially in order to treat or prevent a disease; inoculate children against diphtheria
2 : to introduce something into the mind of
3 : to protect as if by inoculation
We introduced phellinus pini, to encourage heart rot, so that woodpeckers could initiate cavities seeking food sources, and then neotropical songbirds could utilize those cavities for nesting habitat. Some of the biologists took so long a view as to suggest that once those trees got big, with significant levels of heart rot, when they fall could be exploited by bears as winter dens.
Short lengths of wooden dowel, heavily saturated with phellinus pini spores, were inserted into the bored holes. A short section of pvc pipe was inserted after the dowel, extending beyond the bark a few inches, to keep the trees from sealing the holes off with pitch...that would be their normal defense mechanism to a wound that might provide an infection vector.