Abstract: In order to enhance biocontrol efficacy against plant diseases, the combination of different control methods together with a given biocontrol agent can be achieved. In this study we have tested the effect of combining UV-C radiation with the application of biocontrol agents (Bacillus subtillis and Gliocladium catenulatum based products) against Botrytis cinerea on strawberry. We hypothesize that UV-C radiation applied on plants previously to biocontrol treatment, in addition to its induced resistance effect, will somehow disinfect leaves thus limiting the competition of inoculated biocontrol agents with the phyllosphere microorganisms and then promoting its development and its efficacy. We have shown that, despite the confirmed germicidal effect of UV-C radiation, this treatment applied on plants before treatment with biocontrol agent has no effect on the level of efficacy of the biocontrol agents or even it tends to lower their efficacy. Work is in progress to understand mechanisms involved and to evaluate the effect of this combination of treatments on other plant species.