The cold requirement of tulip cultivars
Scientia Horticulturae 7(4): 383-389
ISSN/ISBN: 0304-4238 DOI: 10.1016/0304-4238(77)90012-7
Results of 8 yr of trials were to assess the cold requirements of 116 tulip cultivars, expressed as the number of days of cold (9.degree. C) required to produce flowers in 21 days at 18.degree. C. The data are compared with commerical recommendations for the dates of transferring tulips to the glasshouse for forcing.