Abstract: Germination of common mullein(Verbascum thapsusL.) in relation to constant and alternating temperatures, and light quality and duration was studied. In the dark, optimum germination occurred with 8-h warm periods of 30 to 40 C alternating with 16-h cold periods of 15 to 35 C. In the dark, no germination occurred below 10 C. With light during the 8-h warm periods, germination occurred at temperatures from 2 to 40 C, alternating with 0 C cold periods. The range of optimum temperatures for germination was also greatly expanded with light. Exposure...
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Topics: 
Horticulture
Botany