Beyond the visible: the wavelengths that make the difference
When it comes to lighting for cultivation, most growers know the importance of blue light (for vegetative growth) and red light (for flowering). But there are two often underestimated wavelengths that can make a huge difference in the final results: Far Red (730nm) and UV (385nm).
HortiSpectra lamps both integrate into channel 2 of the Dual-Channel system, and in this article we explain exactly why.
Far Red 730nm: the blooming accelerator
The Far Red is located just beyond the limit of the human visible — we perceive it as an almost invisible dark red light. The plants, however, perceive it very well and react in an extraordinary way.
The Emerson effect
In the 1950s, botanist Robert Emerson discovered that combining red light (660nm) with far red light (730nm) produced an increase in photosynthetic efficiency greater than the sum of the two separate effects. This phenomenon, called the Emerson Effect, is now the basis of the most advanced professional LED lamps.
Basically: adding Far Red to your red light means more photosynthesis with the same amount of energy.
Faster and more abundant flowering
Far Red directly affects phytochrome, the luminous receptor of plants that regulates the transition from the vegetative phase to the flowering phase. Adequate exposure to Far Red:
Accelerates the beginning of flowering
Increase the number and size of the flowers
Reduces the time of the crop cycle
Improves the structure of the tops and fruits
UV 385nm: positive stress that improves quality
Ultraviolet light is often associated with harm — and in excessive doses it really is. But in controlled quantities, UV is one of the most powerful quality stimulators in cultivation.
The defensive response of plants
When plants are exposed to UV, they activate their natural Defence mechanisms, producing greater amounts of:
Resins and terpenes: responsible for the aroma and organoleptic properties of the crop
Anthocyanins and flavonoids: protective pigments that improve colour and nutritional value
Essential oils: higher concentration in flowers and leaves
When to use UV
UV is particularly effective in the last 2-3 weeks of flowering, when plants are completing the development of flowers and fruits. At this stage, gradually increasing the intensity of channel 2 (which includes UV) can significantly improve the final quality of the crop.
How to take advantage of Far Red and UV with HortiSpectra lamps
Thanks to the Dual-Channel system, you can precisely control the intensity of the Red + Far Red + UV channel at each stage of cultivation:
Vegetative phase: channel 2 at 20-30% — light stimulation without excessive stress
Beginning of flowering: channel 2 at 50-70% — activation of the Emerson effect and start of resin production
Advanced flowering: 80-100% channel 2 — maximum stimulation for optimal quality and quantity
Conclusion
Far Red and UV are not optional — they are professional tools that the most experienced growers use to take their crops to a higher level. HortiSpectra lamps integrate them natively, giving you access to uncompromising professional lighting technology.
🌱 HortiSpectra – Grow Strong & Healthy.