Grow Light Spectrum

Grow light spectrum refers to the wavelengths of light emitted by cultivation equipment, ranging from UV through visible to infrared frequencies. Different spectrum profiles—such as blue-heavy vegetative spectra or red-heavy flowering spectra—influence plant morphology, terpene expression, and cannabinoid ratios during development. While light spectrum primarily affects plant physiology and structure rather than producing aroma directly, research suggests spectral composition may modulate secondary metabolite production, including volatile compounds. Breeders and cultivators working with controlled-environment systems track spectrum as an environmental variable affecting phenotypic expression. This is distinct from the plant's genetic terpene profile, though environmental factors can influence which compounds are expressed at harvest.

Breeders conducting phenotype studies in controlled environments document how different light spectra affect terpene and cannabinoid expression across generations. Understanding spectrum-dependent trait variation helps breeders distinguish genetic from environmental influences when evaluating strain consistency.