Abstract
Floral initiation was greatly delayed in four sorghum cultivars [Sorghum bicolor (L.) Moench] and slightly delayed in three other crop plant species (Zea mays L., Helianthus annuus L., and Gossypium hirsutum L.), when grown in atmospheres containing approximately 1, 000 ppm CO2 as compared with plants grown in ambient air. In previous tests, hastened floral initiation had been attributed to enhanced production of photosynthate, a theory which was not confirmed by the present study.
