Testing a new light theory.

[InAwe]

I would have to say that cutting the light time at each end slightly in the last week of harvest definitely made a difference! Any part that was not yet amber turned quickly ntm trichomes started appearing at a faster rate. The smell even intensified in that short period. I would highly recommend doing this in the last week before harvest. (Autos only)

 

[RegularRebel]

So I have seen people talking about keeping your plant in 48 hours of darkness before harvest. I have also seen people talking about dimming the lighting all in order to force the plant into giving it's all as if it were in its final days. Personally, IMHO, this doesn't make much sense because it does not mimic nature. I decided to start reducing the light cycle by 15 min at each end in the final week before harvest. To me, this would semi simulate the shorter days when switching to a colder season. Has anyone tried this or does anyone have any scientific knowledge as to why this would or would not be effective? Thank you much in advance!

Certain types of growers have been doing this for decades. Research "6 hour finish"

 

[amneziaHaze]

Scientific Basis for Light Duration Effects on Flowering Cannabis

1. Photoperiodism and Phytochrome Response

Cannabis is a short-day plant, meaning it flowers when the dark period is long enough. The phytochrome system (red/far-red light receptors) controls this response.

Studies show that shortening the light period accelerates flowering and senescence in short-day plants, including cannabis. (Miyamoto et al., 2012; Adams et al., 2021).

A plant exposed to 10 hours of light will experience a stronger "end-of-life" signal than one with 12 hours, triggering faster completion of flowering.



2. Cannabinoid & Terpene Production Under Different Light Cycles

Studies on cannabis light manipulation (Lyu et al., 2019) suggest that more light hours generally increase cannabinoid production up to a point, but stress from shorter cycles may increase terpenoid accumulation due to a protective response.

A 2021 study (Martínez et al.) found that trichome development is heavily influenced by light exposure, with shorter days accelerating ripening but sometimes reducing total cannabinoid yield.



3. Yield and Bud Density

12 hours of light = more photosynthesis = more biomass. Cannabis plants in longer photoperiods (up to 14-18 hours in vegetative stage) show increased growth and yield (Chandra et al., 2008).

Shorter light exposure (10h) limits daily energy intake, so while maturation speeds up, total yield may be lower.



4. Harvest Timing & Trichome Development

Studies show that trichome maturation (amber vs. cloudy ratio) accelerates under shorter days (Potter & Duncombe, 2012).

This means your 10-hour plant will likely have more amber trichomes at the same calendar time as the 12-hour plant, which may still have more clear/milky ones.

 

[RegularRebel]

Scientific Basis for Light Duration Effects on Flowering Cannabis

1. Photoperiodism and Phytochrome Response

Cannabis is a short-day plant, meaning it flowers when the dark period is long enough. The phytochrome system (red/far-red light receptors) controls this response.

Studies show that shortening the light period accelerates flowering and senescence in short-day plants, including cannabis. (Miyamoto et al., 2012; Adams et al., 2021).

A plant exposed to 10 hours of light will experience a stronger "end-of-life" signal than one with 12 hours, triggering faster completion of flowering.



2. Cannabinoid & Terpene Production Under Different Light Cycles

Studies on cannabis light manipulation (Lyu et al., 2019) suggest that more light hours generally increase cannabinoid production up to a point, but stress from shorter cycles may increase terpenoid accumulation due to a protective response.

A 2021 study (Martínez et al.) found that trichome development is heavily influenced by light exposure, with shorter days accelerating ripening but sometimes reducing total cannabinoid yield.



3. Yield and Bud Density

12 hours of light = more photosynthesis = more biomass. Cannabis plants in longer photoperiods (up to 14-18 hours in vegetative stage) show increased growth and yield (Chandra et al., 2008).

Shorter light exposure (10h) limits daily energy intake, so while maturation speeds up, total yield may be lower.



4. Harvest Timing & Trichome Development

Studies show that trichome maturation (amber vs. cloudy ratio) accelerates under shorter days (Potter & Duncombe, 2012).

This means your 10-hour plant will likely have more amber trichomes at the same calendar time as the 12-hour plant, which may still have more clear/milky ones.

Skotoperiod is way more important to short day plants. They need light, but love darkness.