ARS | Publication request: The rise and fall of carbon dioxide: Why controlling CO2 may be necessary in greenhouses

Submitted to: Growertalks
Publication Type: Trade Journal
Publication Acceptance Date: December 20, 2012
Publication Date: January 14, 2013
Citation: Frantz, J. 2013. The rise and fall of carbon dioxide: Why controlling CO2 may be necessary in greenhouses. Growertalks. 76(9): 64-68.

Technical Abstract: In the winter production cycle, many of us focus on sealing up gaps in an effort to decrease air infiltration, and cut our heating bills substantially along the way. While making these changes or upgrades, we ignoring something the potential impact this has on carbon dioxide (CO2) and plant growth. In a closed greenhouse during the day, the plants are feeding on the available CO2, and the less there is, the less they grow. We can estimate how quickly CO2 can drop from initial conditions through a few assumptions, and those estimates have matched well with informal surveys of greenhouses in NW Ohio in the winter. Controlling CO2 is commonly done in the vegetable production industry, but is not as widely done in the ornamental industry. A test of combining CO2 control with lower temperatures was conducted at a commercial facility. One greenhouse was set to a CO2 concentration of 500 ppm, and a temperature of 62°F while the other was left uncontrolled for CO2, and a temperature set point of 65°F. Results showed enhanced growth and development of vegetative cuttings and lettuce while lowering the cost and carbon consumed. These results are an encouraging step forward to design heating/control systems in a production environment in a more economical and environmentally friendly manner.