Investigation of the effect of day length through black cloth treatment on flowering of potted poinsettia (Euphorbia pulcherima Willd. ex Klotzsch) and evaluation of its longevity under indoor conditions

D.P. Karunananda, S.E. Peiris
In the introduction of poinsettia (Euphorbia pulcherima Willd. ex Klotzsch) as a novel pot plant to Sri Lankan floriculture industry, artificial induction of flowers under long day conditions (off season) is necessary for it to produce marketable plants throughout the year. In this study, feasibility of force blooming during off season was investigated by subjecting vegetative plants to black cloth treatment for two different durations as continuous application until anthesis (8 weeks), discontinuing in the flower initiation (6 weeks) while exposing plants to normal day lengths as the control. Degree of retention of attractiveness of the force bloomed plants was also studied under different indoor conditions (light levels). Plants subjected to continuous black cloth treatment (8 weeks) produced flowers and colorful bracts as flowering in the season and colorful bract production was ceased when the treatment was discontinued at the 6th week. Untreated plants did not produce flowers or bracts. Leaves, bracts and bract color remained unchanged for a long period (8 weeks) under 30.4-76 µmol m‑2 s‑1 light level compared to lower light (0.019-0.95, 0.95-3.8, and 3.8-30.4 µmol m‑2 s‑1) conditions.
Karunananda, D.P. and Peiris, S.E. (2020). Investigation of the effect of day length through black cloth treatment on flowering of potted poinsettia (Euphorbia pulcherima Willd. ex Klotzsch) and evaluation of its longevity under indoor conditions. Acta Hortic. 1278, 211-218
DOI: 10.17660/ActaHortic.2020.1278.31
https://doi.org/10.17660/ActaHortic.2020.1278.31
Sri Lankan floriculture industry, artificial induction of flowers, year around production
English

Acta Horticulturae