Resumen
Two sets of observational carbon stellar yields for low-and-intermediate mass stars are computed from planetary nebulae abundances derived from C II lambda 4267 and C III lambda lambda 1906 + 1909 lines, respectively. By comparing C/O values observed in stars of the solar vicinity and Galactic H II regions with those predicted by chemical evolution models for the Galaxy, which assume these observational yields, I conclude that the C abundances derived from permitted lines are better than those derived from forbidden lines.
