Unlike many other SD cultivars adapted
to high-latitude environments (Darrow and Waldo, 1934;
Heide, 1977; Guttridge, 1985), these cultivars do not display the
day length temperature interaction that renders many
cultivars day length independent below a certain intermediate
temperature. On the other hand, floral induction was inhibited
by high temperature even in SD, with marginal SD induction
taking place at 27 8C (Table 5).