The Influence of Carbon Monoxide and Other Gases upon Plants

Carbon monoxide and illuminating gas experiments have been conducted on seedlings of Vicia faba, Zea mays, Sinapis alba, Helianthus annuus, Triticium vulgare, Fogopyrum, and Oryza sativa. The effects of these gases included: (1) growth in length; (2) growth of secondary membranes; (3) growth in thickness; (4) growth curvatures; and (5) formation of chlorophyll. In the experiments the nitrogen of the air was replaced with either CO or illuminating gas. Nitrous oxide studies were also conducted. The experiments proved that CO is highly toxic when used to replace, partially or entirely, the nitrogen of the atmosphere. The experiments have not yet proved the point at which it ceases to be toxic, or to determine whether or not, like CO/sub 2/, it stimulates growth when present in small proportions in the atmosphere. It has shown that a wide range of reaction to CO is to be found among plants. The deleterious action of the CO results in modifications, of the rate and amount of growth, of the differentiations of the primary tissues, and the formation of chlorophyll. Illuminating gas containing proportions of CO slightly above and below 40%, affords, in addition to the toxic action of the CO, the results of themore » action of other substances deleterious to the plant.« less