In modern extended-season production systems, strawberry
plants are manipulated in artificial environment for the production of more than one crop a year. Under such conditions,
full control of the various stages of the strawberry plant life cycle
becomes essential. In a commercial greenhouse production
system developed in Norway, ‘Korona’ strawberry plants are
induced to flower three times during the winter season by
repeated SD treatments intercalated in July, September and
December in an otherwise continuous LD regime. Berries are
then harvested from November to June (Sønsteby et al., 2004). In
this production system, no chilling is employed, the temperature
being maintained above 15 8C throughout the cultivation period.
Despite the intercalated SD floral induction periods of 3–4
weeks, both vegetative and generative plant development have
been normal with only a temporary reduction in petiole length
towards the end of the SD periods.