Blue LED Supplemental Lighting Enhances Flowering and Fruit Yield of ‘Kuemsil’ Strawberries

Abstract

Strawberries (Fragaria xananassa Duch.) are grown in greenhouses during the winter season in Korea. Nevertheless, the light intensity in winter is lower compared with that during other seasons of the year, which can lead to inadequate photosynthesis for optimal strawberry yield. As a result, supplemental lighting is used to compensate for the lack of natural sunlight for cultivation of strawberries. However, because strawberries are classified as short-day and lowtemperature plants, extending the daylength with supplemental lighting can hinder or prevent flowering. Although reports suggested that blue light can induce flowering in short-day plants, regardless of the photoperiod, few studies of strawberries have been conducted. This study was performed to assess the effects of blue light-emitting diode (LED) lights for supplemental lighting during different growth phases-after planting (AP), first flower cluster (1F), and second flower cluster (2F) phases-on flowering and fruit production of ‘Kuemsil’ strawberries. Untreated plants were used as control (CL). Strawberries were transplanted on 15 Sep 2023. The supplemental lighting treatments (blue LED; peak: 450 nm; photosynthetic photon flux density: 140 ± 5 lmol·m