Kortedagplant

Kortedagplant, literally meaning “short-day plant” in Dutch, is a term used in botany to describe species whose flowering is triggered when the length of the light period falls below a species-specific threshold. These plants require longer nights (shorter days) to initiate blooming and may not flower under normal long-day conditions.

Flowering in kortedagplanten is governed by photoperiodism. Many of these species respond to a critical night length (CNL). The process involves light perception systems, such as phytochromes, and the plant’s circadian rhythms; when nights reach or exceed the critical duration, signals activate flowering in the shoot apical meristem. Some short-day plants respond qualitatively to a specific night length, while others respond in a more graded or quantitative manner.

Examples of kortedagplanten include chrysanthemum, poinsettia, and soybean. These plants commonly flower in autumn or winter under natural conditions in temperate regions, and are widely cultivated under controlled photoperiods to achieve specific blooming schedules.

In cultivation, photoperiod management is a key tool. For short-day plants, extending the day or providing night-break illumination during the natural dark period can delay flowering, while ensuring sufficiently long nights promotes bloom at the desired time. Temperature and other factors, such as vernalization, can interact with photoperiod to influence the floral transition.

See also photoperiodism, plant flowering responses, and horticultural lighting strategies.