Claim · model-written summary
Raising PAR through a longer LP increased growth rate more than raising PFD did.
- Treatment
- by increasing the LP from 16 to 20 h·day-1e5
- Outcome
- growth ratee5
- Direction
- increasede5
- Qualifier
- more than increasing the PFD dide5
- Comparator
- increasing the PFDe5
RosaNot reportedMaterialGeneCompoundOrgan / stageInteractorInteractor roleSecond interactorSecond interactor roleSettingValue
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Miniature roses (Rosa sp.) were grown at 100 and 150 μmol m-2·s-1 photon flux densities (PFD) with 16, 20 and 24 h·day-1 lighting periods (LP)”
e5“Increasing the photosynthetic active radiation (PAR) by increasing the LP from 16 to 20 h·day-1 increased the growth rate more than increasing the PFD did”
Title
Leiv M. Mortensen American Journal of Plant Sciences 2014. doi:10.4236/ajps.2014.513194
Other claims from this paper (11)
- Intervention effect Days to flowering of miniature roses decreased as photon flux density and lighting period increased.
- Intervention effect Days to flowering were unaffected by the timing of the 16 and 20 h/day lighting periods.
- Intervention effect Increasing PFD raised flower number and plant dry weight by 20% to 30%.
- Intervention effect Increasing LP from 16 to 20 h/day raised plant dry weight by about 25%.
- Intervention effect Increasing LP further to 24 h/day had no effect on plant dry weight.
- Intervention effect Increasing PFD or LP from 16 to 20 h/day raised mean growth rate until flowering by 30% to 40%.
- Intervention effect Increasing LP to 24 h/day had little effect on mean growth rate until flowering.
- Intervention effect Leaves grown without a dark period lost considerably more water after detachment.
- Intervention effect Keeping quality of cut miniature roses was unaffected by the treatment.
- Intervention effect Powdery mildew developed significantly more on plants with an 8 h dark period than on other treatments.
- Recommendation Growing miniature roses under 20 h/day lighting with a 4 h dark period and at least 150 μmol·m-2·s-1 PFD is recommended for high-quality pot roses in winter.