Boosting Cannabis Yields by 35%: The Benefits of Adjusting Your Light Schedule

When it comes to indoor cannabis cultivation, every grower is searching for ways to maximize their yield and quality. While many techniques focus on optimizing nutrients, training methods, or environmental conditions, there’s one factor that often gets overlooked: the light schedule. Recent research shows that by adjusting your photoperiod beyond the traditional 12/12 light schedule, you could see a 35% increase in yields—without sacrificing quality.

In this blog, we will delve into the findings of three critical studies that illustrate how adjusting your light schedule can be a game-changer for commercial and serious growers alike.

The Standard 12/12 Light Cycle: Tradition vs. Optimization

For years, the 12/12 light schedule has been the standard for cannabis flowering. Under this regime, plants receive 12 hours of light and 12 hours of darkness each day during the flowering stage. The idea is that the 12-hour cycle mimics the natural photoperiod that triggers flowering in cannabis plants. However, new evidence suggests that this might not be the most efficient approach for all cultivars.

While 12 hours of light may get the job done, it may not be fully optimized for maximizing yields. According to several studies, a longer photoperiod can significantly increase growth and yield without compromising plant quality.

Key Study Insights: Why Longer Light Cycles Work

Several studies have explored the impact of extending the light cycle beyond the traditional 12 hours. Here are the critical takeaways:

1. Photoperiod Extension Can Increase Yields by 35%
Research has shown that cannabis cultivars can initiate flowering under light cycles longer than 12 hours. The main benefit? A 35% increase in total inflorescence yield with just an additional hour of light (13 hours of light). This is largely because a longer photoperiod provides a higher Daily Light Integral (DLI), the total amount of light received by the plant each day. Interestingly, the observed yield increases were disproportionately higher than the increase in DLI, suggesting that the photoperiod itself plays a significant role in plant productivity.

2. Minimal Impact on Flower Quality
One concern with extending the light cycle is that it could affect flower quality, but the research tells a different story. Despite a slight delay in flower maturation—slower stigma browning and reduced trichome ambering—cannabinoid composition remained comparable between the 12-hour and 13-hour treatments. In other words, while flowering development took longer, the final product was just as potent and flavorful.

3. Delayed Flowering with Extended Photoperiods
Extended photoperiods do have an impact on flowering time. The studies found a delayed time to visible inflorescences and slower early floral development in the test cultivars. However, the increased yields more than compensated for the slightly extended flowering phase.

Why You Should Rethink Your Light Schedule

Simple and Cost-Effective
One of the most significant findings from the studies is that extending the light cycle is a simple and cost-effective way to increase yield. While techniques like advanced training methods or nutrient optimization can be costly and labor-intensive, adjusting your light schedule requires no additional investment in equipment. It’s an easy change that could provide a substantial boost in production.

Increased Yield, Same Quality
Perhaps the most exciting aspect of this research is that the yield increase comes without any degradation in quality. The cannabinoid profiles of plants grown under the extended light cycles were comparable to those grown under the traditional 12/12 cycle, making this an ideal technique for commercial growers looking to scale up production without sacrificing the potency or flavor of their crop.

Considerations for Growers

Before you go ahead and extend your photoperiod, here are a few things to consider:

• Cultivar-Specific Adjustments
Not all cannabis strains will respond the same way to extended light cycles. While the studies show promising results, it’s important to understand the specific needs of your cultivars before making changes.

• Delayed Flowering
Be prepared for a slightly delayed flowering period, particularly in the early stages. While the extended photoperiod increases yield, it may also push back your harvest timelines by a small margin.

• Monitor Final Flower Maturity
Keep an eye on your plants’ maturity, as some extended light cycles may result in slower trichome ambering and stigma browning. Patience is key here; the increased yields will be worth the slightly longer wait.

Conclusion: Is It Time to End 12/12?

The research is clear: adjusting your light schedule from the traditional 12/12 can significantly boost yields—by as much as 35%—while maintaining the same level of quality. For commercial and serious growers, this is a game-changing technique that is simple, cost-effective, and backed by scientific evidence.

As more research emerges, we may find that the 12-hour flowering photoperiod is not optimized for all cannabis cultivars. By exploring longer photoperiods and making informed adjustments, growers could unlock higher yields and maximize their operation’s potential.

Mammoth Recommendation for an 8 week strain:

Start at 13 on / 11 off for first 4-5 weeks, then 12 / 12 to finish up or even 10/14.  This will still initiate and promote flowering and provide higher DLI for additional growth/yield.  This also mimics nature...what the plant evolved under for millions of years!!   

 LINKS:

Longer Photoperiod Substantially Increases Indoor-Grown Cannabis’ Yield and Quality: A Study of Two High-THC Cultivars Grown under 12 h vs. 13 h Days (mdpi.com)

 Is Twelve Hours Really the Optimum Photoperiod for Promoting Flowering in Indoor-Grown Cultivars of Cannabis sativa? (mdpi.com)

 Moving Away from 12:12; the Effect of Different Photoperiods on Biomass Yield and Cannabinoids in Medicinal Cannabis (mdpi.com)

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