Van Delm T.,National Research Center for Strawberries |
Melis P.,National Research Center for Strawberries |
Stoffels K.,National Research Center for Strawberries |
Baets W.,National Research Center for Strawberries
Acta Horticulturae | Year: 2012
Between a first harvest period in autumn and a second in spring, strawberry plants in a glasshouse need sufficient chilling for breaking dormancy. A lack of chilling leads to unsatisfactory elongation of petioles and inflorescences, poor flower quality and a lower production. This lack of chilling can be compensated by artificial lighting used for a night-break treatment. Since the common incandescent lamps will cease to be available, there is a need for an alternative. This research focused on the possibilities of using fluorescent and LED lamps as replacement for the incandescent lamps. Therefore, three treatments with 28, 55 and 82% of the chilling requirement of the cultivar 'Elsanta' were made. At each level of chilling, 11 light treatments were compared. Two compact fluorescent lamps were tested continuously and cyclically. Five LEDs with different blue, red and far-red wavelengths were evaluated. A cyclic incandescent lamp and an unlighted object were added as controls. The results demonstrate that fluorescent lamps are less effective than the incandescent lamps, but they can give satisfying results under certain conditions. The effect of some LEDs were comparable with the incandescent lamp, but the presence of far-red light seems to be an important element for breaking dormancy and thereby improving elongation, fruit set and yield. This research proves that LEDs have potential for replacing the incandescent lamp.