  The cross sections for the charmonium production processes p pbar -> m Psi,
where m is a light meson and Psi is a charmonium state, are of great interest
for the planned p-pbar experiment PANDA. In this paper we estimate these cross
sections using known results for the decays Psi -> m p pbar which are related
to these reactions by crossing. In lieu of detailed experimental data on the
decay Dalitz plots, we assume a constant amplitude as a first approximation;
this implies a simple relation between the cross sections and decay widths. The
single measured exclusive cross section of this type is p pbar -> pi0 J/psi,
which was reported by E760 to be 130 +/- 25 pb near sqrt(s) = 3.5-3.6 GeV. In
comparison, our constant amplitude estimate is about 300 pb at this energy.
This suggests that our approach is useful as a simple estimate, but should be
refined through detailed modeling of resonances and other energy-dependent
effects in the experimental Psi -> m p pbar Dalitz plots.
