Gas exchange and growth of plants under reduced air pressure

This paper begins with a brief review of the few reports on methods and results on growing plants at reduced air pressure. Then a new experimental set-up developed by the authors is described and discussed. This set-up permits growth of plants to a total height of 35 cm. Climatic conditions and gas pressures are carefully controlled and CO2-consumption is measured. Results with tomato plants by lowering air pressure to 400 to 700 hPa are reported and compared to plants maintained at 1000 hPa. These studies showed some growth reductions, morphological changes, and enhanced transpiration at 400 hPa.