Potato (Solanum tuberosum L. cv. Benimaru) plantlets were cultured photoautotrophically (in sugar-free
medium) in vitro under three levels of vessel ventilation rate per plantlet and two levels of photosynthetic photon flux
(PPF). The parameters of the net photosynthetic rate model for potato plantlets in vitro were estimated according to the
measured CO2 concentrations inside and outside the vessel. Computer simulations of the time courses of CO2
concentration in the vessel and dry weight of potato plantlets were made for a 15-day culture period. The CO2
concentration in the vessel during the culture period and the dry weight of potato plantlets in vitro in the late part of the
culture period were influenced significantly by the vessel ventilation rate per plantlet. The steady-state CO2 concentration
during the photoperiod decreased with time during the culture period. Simulated results generally agreed with the
experimental data and demonstrated the usefulness of computer simulations.