  In this paper we investigate the fermionic condensate and the renormalized
vacuum expectation value (VEV) of the energy-momentum tensor for a massive
fermionic field induced by a flat boundary in the cosmic string spacetime. In
this analysis we assume that the field operator obeys MIT bag boundary
condition on the boundary. We explicitly decompose the VEVs into the
boundary-free and boundary-induced parts. General formulas are provided for
both parts which are valid for any value of the parameter associated with the
cosmic string. For a massless field, the boundary-free part in the fermionic
condensate and the boundary-induced part in the energy-momentum tensor vanish.
For a massive field the radial stress is equal to the energy density for both
boundary-free and boundary-induced parts. The boundary-induced part in the
stress along the axis of the cosmic string vanishes. The total energy density
is negative everywhere, whereas the effective pressure along the azimuthal
direction is positive near the boundary and negative near the cosmic string. We
show that for points away from the boundary, the boundary-induced parts in the
fermionic condensate and in the VEV of the energy-momentum tensor vanish on the
string.
