Formation of Carbon Monoxide during Seed Germination and Seedling Growth.

Carbon monoxide was formed during the growth of cucumber seedlings in the dark in atmospheres containing 5 percent oxygen or less, but not by aerobic seedlings. The highest level recorded was 6000 ppm. Carbon monoxide was also formed by Euphorbia. Germinating seeds of rye, cucumber, and other species also produced carbon monoxide at levels of 10 to 25 ppm.