  The prompt production of the charm baryon $\rm \Lambda_{c}^{+}$ and the $\rm
\Lambda_{c}^{+}/\mathrm {D^0}$ production ratios were measured at midrapidity
with the ALICE detector in pp and p-Pb collisions at $\sqrt{s_\mathrm{NN}} =
5.02$TeV. These new measurements show a clear decrease of the $\rm
\Lambda_{c}^{+}/\mathrm {D^0}$ ratio with increasing transverse momentum
($p_{\rm T}$) in both collision systems in the range $2<p_{\rm T}<12$ GeV/$c$,
exhibiting similarities with the light-flavour baryon-to-meson ratios ${\rm
p}/\pi$ and $\Lambda/\mathrm {K^0_S}$. At low $p_{\rm T}$, predictions that
include additional colour-reconnection mechanisms beyond the leading-colour
approximation; assume the existence of additional higher-mass charm-baryon
states; or include hadronisation via coalescence can describe the data, while
predictions driven by charm-quark fragmentation processes measured in $\mathrm
{e^+e^-}$ and $\mathrm {e^-p}$ collisions significantly underestimate the data.
The results presented in this letter provide significant evidence that the
established assumption of universality (colliding-system independence) of
parton-to-hadron fragmentation is not sufficient to describe charm-baryon
production in hadronic collisions at LHC energies.
