Four range grass species—Oryzopsis holciformis, Phalaris tuberosa, Agropyrum desertorum (Nordan and Fairway), and Agropyrum elongatum—as compared to wheat were germinated in atmospheres containing different concentrations of oxygen and carbon dioxide. The grasses, in the absence of CO₂, showed significant decreases in the time rate of germination and in the final germination percentage over the whole range of oxygen concentrations tested; whereas wheat showed only a slight delay in germination with decreasing oxygen concentrations.

The initial (imbibitional) water uptake of all plants was not affected by oxygen concentrations, while the CO₂ production (respiration) decreased at low O₂ concentrations at this stage. Subsequently, the seed water uptake was parallel to the germination response.

The effect of CO₂ (O — 15%) on germination was slight as compared to the oxygen effect.