- Spectrum tuning with horticulture LEDs can optimize plant growth and development.
- The Daily Light Integral (DLI) is a measure of light quantity in horticulture.
- The critical inductive photoperiod determines when a cannabis plant will flower.
- Flowering photoperiods can have a significant impact on yield and potency.
When it comes to growing cannabis, maximizing yields is a top priority for many cultivators. One way to achieve higher yields is by optimizing the photoperiod, or the duration of light exposure, during different stages of plant growth. By understanding photoperiod hacks and implementing them correctly, growers can boost their cannabis harvest. This article will explore the various techniques and strategies to increase yields through cannabis photoperiod manipulation.
Horticulture LEDs now offer the ability to tune the light spectrum, allowing growers to provide different light spectra during different developmental phases of the plant. For example:
- A blue-shifted spectrum promotes compact vegetative growth.
- A red-shifted spectrum promotes generative (flowering) development.
- Far-red light is used as an end-of-day treatment to quickly convert phytochrome at the onset of the skotoperiod.
By utilizing the right spectrum at the right time, growers can optimize growth and development, leading to increased yields.
Light Quantity – Daily Light Integral (DLI)
The Daily Light Integral (DLI) is a measure of the cumulative amount of light received by a plant each day. It is calculated by multiplying the light intensity by the photoperiod duration and is expressed in mol. The DLI targets for different crops are determined based on the point at which additional light no longer has a linear effect on yield.
For cannabis, a light-loving crop, the recommended DLI target is at least 50 mol. It’s important to note that additional light will not improve plant performance unless other cultural conditions are adequately met.
The inductive photoperiod is the specific photoperiod required for a cannabis cultivar to initiate flowering. While some tropical landrace varieties may require 12 or more hours of darkness to flower, most commercial cultivars will flower with 10-10.5 hours of darkness.
After exposure to the critical inductive photoperiod for four to five days, hormones and signaling compounds trigger a cascade effect that commits the plant to flower formation. Recent research has shown that different flowering photoperiods can have a significant impact on yield and potency, which varies among different cultivars.
Here are some examples:
- Cannatonic, a CBD-rich cultivar, had more than doubled its yield when flowered under a 14/10 light cycle compared to the control at 12/12. The CBD percentage of the flower was the same for both treatments.
- Hindu Kush, a THC cultivar, experienced an increase in biomass but a decline in potency under a continual 14/10 light treatment compared to the control.
- Northern Lights performed best when a 14/10 light schedule was applied for the first half of the flowering stage, followed by a 12/12 photoperiod for the second half. This treatment resulted in a 50% gain in yield without any reduction in potency.
It’s crucial to trial any changes to cultivation practices before applying them to commercial crops. The critical inductive photoperiod can be measured using a small grow chamber or tent, gradually reducing the photoperiod until flowering is observed.
Optimizing the cannabis photoperiod is an effective way to increase yields. By utilizing spectrum tuning, understanding the Daily Light Integral, and determining the critical inductive photoperiod, growers can maximize the growth and development of their cannabis plants, leading to higher yields and potentially increased potency. However, it’s essential for cultivators to experiment and adapt these techniques to their specific cultivars and growing conditions.
1. How can spectrum tuning help increase cannabis yields?
Spectrum tuning with horticulture LEDs allows growers to provide specific light spectra during different stages of plant growth. This optimization can promote vegetative growth or flowering development, leading to higher yields.
2. What is the Daily Light Integral (DLI) in horticulture?
The DLI is a measure of light quantity in horticulture. It is determined by the cumulative amount of light received by plants each day and is calculated by multiplying the light intensity by the photoperiod duration. DLI targets are set based on the point at which additional light no longer has a linear effect on yield.
3. How does the photoperiod affect cannabis flowering?
The critical inductive photoperiod determines when a cannabis plant will initiate flowering. Different flowering photoperiods can have varying effects on yield and potency. It is essential for growers to experiment and adapt the photoperiod to their specific cultivars and desired outcomes.