Reference Area


Here's the companion article looking at light intensity in the flowering stage:

Cannabis Yield, Potency, and Leaf Photosynthesis Respond Differently to Increasing Light Levels in an Indoor Environment
"... plants were grown for 12 weeks in a 12-h light/12-h dark “flowering” photoperiod under canopy-level PPFDs ranging from 120 to 1,800 μmol·m−2·s−1 provided by light emitting diodes.

"It was predicted that cannabis yield would exhibit a saturating response to increasing LI,
thereby signifying an optimum LI range for indoor cannabis production.

"However, the yield results of this trial demonstrated cannabis’ immense plasticity for exploiting the
incident lighting environment by efficiently increasing marketable biomass up to extremely high—for
indoor production—LIs (Figure 7A).

"Even under ambient CO2, the linear increases in yield indicated
that the availability of PAR photons was still limiting whole-canopy photosynthesis at APPFD levels as
high as ≈1,800 μmol·m−2·s−1 (i.e., DLI ≈78 mol·m−2·d−1)."

Last edited:


Article on defoliating and branch removal. Pruning treatments are “Topping”.

Plant architecture manipulation increases cannabinoid standardization in ‘drug-type’ medical cannabis
The treatments that increased the most the concentrations of the lower inflorescences thus
increasing standardization were ‘Double prune’, and the removal of bottom branches and leaves (BBLR).

"However, it should be noted, that surprisingly, and contrary to common belief in the cannabis industry,
the changes in cannabinoid concentrations (Fig. 2–4) and yield (Fig. 5C-D) were small (except for the
‘1◦ branch removal’ treatment that greatly reduced both parameters).

Last edited:


MNS Hall of Fame
i remove only if the leaves are sick or brown
at the end of the bloom the plant remove it by itself
for that you need a good nitrogen carency for the plant eat its

i always remove the bottom branchs

i do like that not sure if is good or not
after that depend of the plant too

it's very interesting


Is this research from Oregon State any good? It's a little (ok a lot) technical for me :)!
Pretty cool if cannabis blocks covid!

Link to research article:

Cannabinoids Block Cellular Entry of SARS-CoV-2 and the Emerging Variants
" Hemp compounds identified by Oregon State University research via a chemical screening technique invented at OSU show the ability to prevent the virus that causes COVID-19 from entering human cells. "



Oops! Apologies ... Big Sur posted on this yesterday.


New member
Is this research from Oregon State any good?
"To validate the virus neutralizing capabilities of CBDA and CBGA, we next performed focus forming assays using authentic SARS-CoV-2 virus (Isolate USA-WA1/2020). We utilized Vero E6 cells for these experiments due to their high susceptibility to the virus and common use in SARS-CoV-2 live-virus studies. Focus forming assays were performed using serial dilutions of CBDA or CBGA that were incubated with infectious SARS-CoV-2 for 1 h prior to infection. As in the pseudovirus neutralization assay, CBDA and CBGA prevented SARS-CoV-2 entry into Vero E6 cells with IC50 values of 24 and 37 μg/mL (Figure 3D–F), respectively."

they use "authentic" virus but fake cells. what about real human cells? what about real humans? nope. i guess they couldn't find people in Portland who are taking undecarbed extract and see if they're more or less likely to test positive.

what does it take to obtain a blood plasma level of CBDA equal to the level where half the cells with "high susceptibility to the virus" are infected? administers about 9 milligrams CBDA to people and finds average peak plasma CBDA of 74 nanograms/milliliter. 0.000822% of the dose. extrapolation of 74 nanograms to 24 micrograms requires eating 2919 milligrams of CBDA. every hour. because the level rises and falls very quickly (average plasma peak at 0.83 hours, half-life 0.84 hours). liver damage would not be a surprise here.

the authors are aware of all that.