This experiment has given strong evidence that cuttings
of the Washington Navel orange variety are sensitive to both
temperature and photoperiod. Vegetative growth occurred in
all six treatments and flower initiation occurred in only two
of the treatments. This indicates direct participation of
photoperiod and temperature in the flowering process. Since
flowers only occurred on short days and at low tempera
tures, this variety of orange could be described as a
temperature dependent qualitative short day plant.