  Aims: Grain growth has been suggested as one possible explanation for the
diminished dust optical depths in the inner regions of protoplanetary
"transition" disks. In this work, we directly test this hypothesis in the
context of current models of grain growth and transport.
  Methods: A set of dust evolution models with different disk shapes, masses,
turbulence parameters, and drift efficiencies is combined with radiative
transfer calculations in order to derive theoretical spectral energy
distributions (SEDs) and images.
  Results: We find that grain growth and transport effects can indeed produce
dips in the infrared SED, as typically found in observations of transition
disks. Our models achieve the necessary reduction of mass in small dust by
producing larger grains, yet not large enough to be fragmenting efficiently.
However, this population of large grains is still detectable at millimeter
wavelengths. Even if perfect sticking is assumed and radial drift is neglected,
a large population of dust grains is left behind because the time scales on
which they are swept up by the larger grains are too long. This mechanism thus
fails to reproduce the large emission cavities observed in recent
millimeter-wave interferometric images of accreting transition disks.
