Susceptibility of common sapstaining fungi to antisapstain products was exa
mined using a rapid antisapstain laboratory disc trial. The ability of fung
al isolates to colonise radiata pine branchwood discs treated with various
commercial antisapstain formulations was used as an indicator of fungicidal
susceptibility or tolerance. The results of this investigation showed that
under laboratory conditions, susceptibility to antisapstain formulations v
aried greatly, both between species, and between isolates of the same speci
es. None of the formulations gave consistent control of all the isolates wh
en tested at commercial usage rates. The significance of these results is d
iscussed in terms of design of laboratory antisapstain trials and its poten
tial relevance in the field.