Micropropagation: Effects of ventilation and carbon dioxide level on rhododendron 'P.J.M.'

The purpose of this study was to determine if ventilation, either with or without carbon dioxide enrichment, should be used in the design of vessels for a micropropagation system. Rhododendron 'P.J.M.' cuttings were grown using standard Stage II micropropagation techniques except that the vessels were ventilated. The ventilation treatments were filtered atmospheric air and bottled nitrogen and oxygen mixtures with 0, 300 and 1000 ppm carbon dioxide. Nonventilated vessels were used as controls. The results showed that plant fresh weight and number of shoots in the nonventilated vessels were significantly higher at the 5% level than in the ventilated vessels and that there was no significant difference between any of the ventilated treatments.