Flowering & Reproductive Development
Photoperiod Response Variation & Flowering Thresholds
Cannabis flowering response varies with genotype and developmental state. Photoperiod should be treated as a biological signal with cultivar-dependent response rather than a universal switch that acts identically in every plant.
Key concepts
- Many cannabis genotypes are photoperiod responsive
- Critical daylength and response speed can vary
- Photoperiod-insensitive or weakly sensitive genotypes exist
- Light quality, timing, plant age, and genetics interact with flowering pathways
What to measure or observe
- Record actual light and dark timing
- Track first floral structures by plant
- Compare genotypes separately
- Document changes in photoperiod rather than only calendar date
Common mistakes
- Assuming every cultivar responds identically to the same schedule
- Calling photoperiod the only flowering signal
- Ignoring unintended night light
- Using one plant's transition date as the population response
Visuals this lesson still needs
- Genotype response curves
- Photoperiod timeline
- Population flowering distribution
- Signal-versus-response diagram