Plant Disease Progress Can Be Monitored by CO ₂ Gas Exchange of the Plant Canopy

The occurrence of disease epidemics in bioregenerative life support systems would seriously limit the production of essential life support requirements. The capacity of diseased plants in closed environment chambers to scrub CO₂ was studied with lettuce plants infected with a common greenhouse pathogen, Pythium.At harvest, infected lettuce showed less edible biomass, decreased leaf area, and reduced photosynthesis averaging 50% on a per chamber basis. These results and others are discussed to show the potential of using existing instrumentation in life support systems to monitor the health of the plant canopy, predicting early onset of disease and refining remediation strategies.