A Deep Dive Into Daily Light Integral

One way growers can dial in their environment is by managing daily light integral or DLI, which measures the cumulative light energy available to plants – crucial for photosynthesis and overall plant health – within a given time period. In this post, we’ll explore why DLI matters in cannabis cultivation, and how growers can manage it effectively to achieve their goals.

Why DLI Matters for Cannabis Cultivation

DLI is calculated by multiplying photosynthetic photon flux density, or PPFD, by the total number of light hours. Expressed as moles of light per square meter per day (mol/m²/day), DLI ultimately reflects the available amount of photosynthetically active radiation, or PAR, photons for that period of time.

Understanding DLI is important because achieving the right light levels helps ensure cannabis plants are able to perform photosynthesis effectively, and lead to robust growth and healthy yields. When Day Light Integral is too low it can cause weaker plants, while DLI that’s too high can create plant stress and hinder growth. Taking the time to monitor and adjust DLI in response to the specific needs of the plant also allows growers to more effectively balance their energy use with plant growth – and potentially reduce operational costs. But most importantly, consistent and appropriate light levels achieved with a properly managed DLI can also affect cannabinoid and terpene profiles, resulting in a better quality product.

How to Manage DLI Effectively

Here are some of the techniques growers can use to leverage and dial in their DLI:

1. Use sensors to measure light levels. To get a handle on DLI, growers must first be able to measure the light levels their plants are receiving. Advanced sensor technology that measures light levels and delivers accurate PAR measurements from all light sources can support a grower’s ability to continuously maintain the ideal DLI for their plants.
2. Make lighting adjustments. Access to real-time data gives growers the intelligence to make more informed lighting decisions. Based on DLI readings, cultivators may opt to change the duration of light exposure, adjust the lighting intensity, increase the number of hours that lights are on, and much more based on what they’re seeing with the data.
3. Track, monitor, and adapt. DLI should be monitored regularly to ensure it stays within the optimal range for each phase of plant growth. The angle of light, the distance of light from the plants, and overall lighting intensity are just a few of the environmental factors that can impact DLI – and it’s essential that growers be prepared to adapt their setup as needed.

Conclusion

DLI is a fundamental concept that can significantly impact plant growth, yield, and quality, and the right sensor technology makes monitoring and adjusting DLI helps growers ensure their plants receive optimal light exposure throughout every growth cycle. Understanding and incorporating DLI can bring more efficiency to cultivation practices, improve overall plant health, and ultimately achieve better results with every harvest. To learn more about DLI, check out these clips from Office Hours Episode 20, Episode 31, and Episode 53.