Photoperiod Dominance

Photoperiod dominance refers to cannabis plants whose flowering is primarily regulated by changes in light duration rather than age or internal genetics. Traditional photoperiod varieties require a shift to shorter daylight hours (typically 12/12 light/dark cycle) to trigger and sustain flowering, making them sensitive to seasonal light changes. This classification contrasts with autoflowering genetics, which flower based on age regardless of light cycle. Photoperiod plants are commonly preferred by breeders for their extended vegetative phase, which allows greater plant development and yield potential. Lineage records frequently show photoperiod dominance in classic cannabis cultivars and most modern breeding stock used in controlled environments.

Breeders working with photoperiod genetics benefit from extended vegetative windows to select phenotypes, create larger plants, and perform advanced techniques like grafting or rogueing. Photoperiod dominance is often crossed with other traits to extend flowering times or strengthen light-dependency in hybrid offspring.