  We have compiled the experimentally measured pbar/p ratio at midrapidity in
p+p collisions from \sqrt{s} = 23 to 7000 GeV and compared it to various
mechanisms of baryon production as implemented in PYTHIA, PHOJET and
HIJING/B-Bbar models. For the models studied with default settings, PHOJET has
the best agreement with the measurements, PYTHIA gives a higher value for
\sqrt{s} < 200 GeV and the ratios from HIJING/B-Bbar are consistently lower for
all the \sqrt{s} studied. Comparison of the data to different mechanisms of
baryon production as implemented in PYTHIA shows that through a suitable tuning
of the suppression of diquark-antidiquark pair production in the color field
relative to quark-antiquark production and allowing the diquarks to split
according to the popcorn scheme gives a fairly reasonable description of the
measured pbar/p ratio for \sqrt{s} < 200 GeV. Comparison of the beam energy
dependence of the pbar/p ratio in p+p and nucleus-nucleus (A+A) collisions at
midrapidity shows that the baryon production is significantly more for A+A
collisions relative to p+p collisions for \sqrt{s} < 200 GeV. We also carry out
a phenomenological fit to the y_beam dependence of the pbar/p ratio.
