Non-target effects can be de¢ned as effects of the introduced
BCA on organisms other than the target organisms
or on biogeochemical cycles. For environmental risk analysis,
direct or indirect non-target e¡ects mediated through
a chain of events or interactions among organisms will
cause concern. Likewise, immediate e¡ects or cumulative
long-term e¡ects will cause concern
An important parameter
is the duration of the e¡ects, as generally large
temporary £uctuations can be accepted [3]. Non-target
e¡ects can be categorized in the same way as Domsch et
al. [3] categorized the side e¡ects of agrochemicals on soil
microorganisms, as negligible, tolerable, and critical, depending
on the magnitude of the e¡ect and the time
needed for the system to recover. The de¢nition of ‘negligible’,
‘tolerable’ and ‘critical’ is, of course, subjective, and
prone to societal and/or political decisions. A prerequisite
for introducing the BCA into the environment is generally
that, in addition to effective disease suppression, the effects
on non-target organisms should be at least tolerable, if not
negligible. Since most target effects are not uniquely species
to pathogens, non-target effects can be expected. Consequently,
considerable e¡ort has been put forth to characterize
and quantify these non-target effects.
In practical
terms, intolerable non-target e¡ects should persist beyondthe time of crop harvest and be signi¢cantly di¡erent from
changes due to growth season and agricultural practices.
This minireview focuses speci¢cally on non-target e¡ects
of bacterial BCAs that are used to control root pathogenic
fungi. It attempts to critically evaluate important published
non-target e¡ect studies, their usefulness in risk
analysis, and their relationship to the success of the
BCA in pathogen control. Finally, we suggest future research
approaches for non-target e¡ects of BCA.