Thus, theoretically the most interesting mode of
action should be SIR. Indeed, after elicitation, the
resistance will be expressed in several if not all plant
tissues and at a great distance from the point of
inoculation of the BCA. But in practice, it is not so
clear. One must remember than in nature a plant is
permanently submitted to stresses of different origins.
Application of a microbiological control
agent might add some degree of resistance to the
already expressed level of resistance, but this might
not be enough to fully protect the plant. Moreover,
as clearly demonstrated with several models, plant
reaction depends on the plant species and even on
the plant cultivar, on the physiological stage of the
plant and on the environmental conditions (Van
Loon, 2000)