Influence of photoperiod on growth and flowering of dwarf purple loosestrife

Abstract

This study was conducted to compare the growth and flowering characters of a dwarf purple loosestrife and purple loosestrife (Lythrum salicaria L.), and to determine the optimal photoperiod of dwarf purple loosestrife for forcing cultivation. Dwarf purple loosestrife was grown under natural sunlight (from 08:30 to18:30 HR, 10 h) and additional artificial lighting [0, 2, 3, 4, 6, or 14 h of continual light, or night interruption of 4 h (NI)] in a greenhouse. Growth and development of dwarf purple loosestrife were promoted by 14, 16, or 24 h or NI. The number of lateral shoots and plant height were higher as daylength was extended. However, the number of nodes was not influenced by photoperiod. The number of inflorescences was 0.6, 2.9, 5.0, or 4.2 under 14, 16, or 24 h, or NI, respectively. Also, plants under NI showed more uniform flowering (86%) than those under 14 h (48%). However, plants under 10, 12, or 13 h never produced inflorescences and remained as rosettes throughout the experiment. Therefore, we concluded that dwarf purple loosestrife has a critical photoperiod, 14-h daylength and NI is the effective method to accelerate growth and flowering for forcing cultivation.Additional key words: Korean native plant, landscape plant, Lythrum salicaria, obligate long day plant, potted plant Hort.

Night Interruption and Night Temperature Regulate Flower Characteristics in Cymbidium

“…Flower induction occurred in Salvia farinacea, Limonium sinuate, and Linaria maroccana (Mattson and Erwin, 2005) , which was influenced merely stronger flowering characteristics compared to HNI. NI has also been shown to accelerate flowering in Cyclamen persicum (Oh et al, 2008) and Lythrum salicaria L. (Kim et al, 2011a). Long days induced accumulation of carbohydrates in Psygmorchis pusilla orchid plants when compared with those cultivated under short photoperiods (Vaz et al, 2004).…”

“…Increasing day length can be promoted Cymbidium growth (Hew and Yong, 2004). Long days (LD) hasten plant development and flowering also in Lythrum salicaria L. (Kim et al, 2011a), Cleome hasslerana, and Helianthus annus (Mattson and Erwin, 2005). To promote flowering in LD plants under short natural photoperiods, day length can be extended with artificial lighting.…”

Vegetative Growth and Flowering of Salvia splendens ‘Salsa’ in Response to Night Interruption

“…)로 4시간(22시-02 시) 동안 야파 처리를 하였을 때 광합성량이 증가하였고 (Kim et al, 2013b), 이로 인해 영양생장이 증가하는 것 뿐만 아니 라 개화가 촉진되었다 (Kim et al, 2011a(Kim et al, , 2011b(Kim et al, , 2013a.…”

Photosynthetic changes in Cymbidium orchids grown under different intensities of night interruption lighting

“…Flowering in LD plants including Cyclamen (Kang et al, 2008), Lythrum (Kim et al, 2011a) and Coreopsis (Runkle et al, 1998) were effectively promoted by NI for 4 h. NI only requires a low photosynthetic photon flux (PPF) of 2-5 mol m −2 s −1 for advancing flowering in LD plants (Blanchard and Runkle, 2009;Park et al, 2013).…”