What Are Ultraviolet (UV) and Infrared (IR) Lights
Ultraviolet (UV) and Infrared (IR) lights are parts of the electromagnetic spectrum, a range of all types of electromagnetic radiation categorized by wavelength. The difference lies in that UV light shares a shorter wavelength while the IR spectrum shares a much longer wavelength.
Ultraviolet (UV) Light
Wavelength Range: 10 to 400 nanometers (nm), shorter than visible light.
Types of UV:
- UVA (315-400 nm): Long-wave UV, linked to skin aging and tanning.
- UVB (280-315 nm): Medium-wave UV, can cause sunburn and skin cancer.
- UVC (100-280 nm): Short-wave UV, highly energetic and used for sterilization; mostly absorbed by Earth’s atmosphere.
Infrared (IR) Light
Wavelength Range: 700 nanometers to 1 millimeter, longer than visible light.
Types of IR:
- Near-IR (700 nm - 1.3 μm): Used in fiber optics and remote controls.
- Mid-IR (1.3 μm - 3 μm): Applied in environmental monitoring and spectroscopy.
- Far-IR (3 μm - 1 mm): Used in thermal imaging and heat detection.
Do Plants Need UV & IR Light
We all know that plants rely heavily on red and blue light to survive and thrive, but when it comes to UV or IR light, is it so? Technically, plants don't require UV and IR light to grow, as they primarily rely on visible light for photosynthesis. However, UV and IR light do bring benefits to plant growth and health, particularly when they are used appropriately in controlled environments such as greenhouses, grow tents, or any indoor gardens.
Ultraviolet (UV) Light and Indoor Plants
On one hand, UV light is effective at recreating a natural environment and therefore making plants act like they are being grown in the wild. The UV light for plants has been known to promote faster photosynthesis, increase leaf areas, increase THC and CBD potency, promote branching, and provide higher resistance to pests.
Proper use of UV lights for plants can also improve plants’ nutritional quality while stimulating biomass production by stressing them. Strains that are grown under UV light tend to have higher dry weights too.
On the other hand, the overuse of UV lamps for plants can lead to light stress, which in turn can hinder plant growth and lower plant yields. This is due to plants spending more energy on producing trichomes as a way of protecting themselves, as opposed to growing larger and more robust. UV stress can also lead to photoinhibition of chloroplasts resulting in lower biomass production, photobleaching, and the death of leaves.
Infrared (UV) Light and Indoor Plants
Infrared (IR) light, particularly in the far-red wavelengths, can trigger the shade avoidance response, where plants sense a lack of direct light and accelerate stem growth to reach for better light conditions. This is especially useful in indoor environments where light conditions are carefully managed.
IR light for plants also enhances the effectiveness of Photosystems I (PSI) and Photosystems II (PSII), which are key components of the photosynthesis process. When IR light is used alongside blue and red light, it can lead to:
- Increased photosynthetic activity.
- Accelerated and more robust stem growth.
- Proper node spacing (preventing overly compact or "leggy" plants).
- Development of more flower buds, supporting reproductive growth.
Additionally, IR light appears to regulate plant circadian rhythms, helping plants transition between growth stages, including sleep and wake cycles. This is particularly critical during the later stages of plant development, as many flowering plants will not bloom until exposed to adequate levels of IR radiation.
While IR light offers numerous benefits, a large portion of IR light manifests as heat. Overexposure can lead to overheating, causing stress, dehydration, and even plant death.
How Can I Apply UV & IR Light to My Cultivation
The most efficient way to use supplemental UV and IR light depends on the specific plants you are growing and the size of your growing space. Different plants have varying requirements for light intensity, Photosynthetic Photon Flux Density (PPFD), UV, and IR exposure. Below is a general guide tailored for weed cultivation, which can be adapted for other crops with proper research.
UV Light Usage in Veg & Flowering Stages
Vegetative Stage
During this fast-growing phase, we suggest you maintain light intensity between 400-600 µmol/m²/s. In addition to the 16-18 hrs of main grow lights, introduce 1 hour of supplemental UV light for plants per day during the mid-to-late vegetative stage. This encourages robust plant development and prepares them for the flowering phase.
Flowering Stage
When in the flowering stage, transition to a more natural light schedule of 12 hours of light and 12 hours of darkness per day to induce flowering. Plants during this stage require light intensity of 800-1,000 µmol/m²/s. To supplement your grow lights, use UV light for plants based on the following schedule:
- Early Flowering Stage: Provide 60-90 minutes of supplemental UV light per day.
- Mid-Flowering Stage: Increase to 90-120 minutes per day.
- Late Flowering Stage (Final 2-3 Weeks): Further increase UV exposure to 120 minutes per day to enhance THC levels and chemical profiles. Monitor plants carefully, as different strains have varying UV tolerance.
IR Light Usage in All Stages
During all growth stages (except germination), apply IR light for a 30-minute time frame before the lights are turned off for the day. To do this, turn the IR lights on for 10 minutes, then off for 10 minutes, and finally on for another 10 minutes before turning off all lights for the night. This process helps prepare plants for their sleep cycle, enhancing metabolic processes during rest.
To optimize plant growth and biomass accumulation, turn on the IR light for 15 minutes before the main lights come on in the morning and 15 minutes after the main lights turn off in the evening. This approach helps plants wake up gradually, ensuring they absorb full-spectrum light more efficiently during the day and transition smoothly into the sleep phase at night.
Mars Hydro UV and IR ADlite Supplemental LED Grow Lights
At Mars Hydro, we designed our products to provide everything plants need to grow and thrive. Specifically, Mars Hydro's ADlite series offers supplemental LED grow lights designed to enhance plant growth by providing targeted light spectrums - Ultraviolet (UV), Infrared (IR), and Deep Red. These lights are intended to complement existing full-spectrum LED grow lights, optimizing plant development and yield, including:
The addition of UV and IR supplemental lights enhances plant growth and resilience. UV exposure stimulates the production of secondary metabolites like flavonoids and anthocyanins, strengthening resistance to pests, stress, and diseases, while also potentially increasing THC levels in certain plants. Meanwhile, IR light (730-745nm) promotes robust stem growth, and proper node spacing, and accelerates the transition from vegetative to flowering stages, contributing to photosynthesis and overall plant development.
Interested in knowing more? Check our comprehensive guide on the ADlite series and decorate your indoor garden with them!
Is this efficient? That’s giving equaling to 120min of blue UV a day. Or should I leave them on for a longer duration and less cycles of lighting. Though it seems to be working this way. Just not sure if there’s a more efficient way to get the most out of Blue UV.
Do you have a suggested schedule for just running BOTH UV and IR simultaneously, so they can be on a timer separately, and still get the benefits??