After reading here and there that keeping a cutting in the dark for a while increase mescaline content, i thought i could make a little experiment.
Process :
- Find a nice specimen like this little fellow named #P5. A T. Peruvianus started from seed, 2 years old 60cm tall :

- Take a cutting :

- Cut the tip to grow it and have a nice piece you can share in 2 almost identical bits :

- The sample will be extracted fresh after the cut :

- The test will be kept in a dark room rolled in a newspaper for 3 month :

- The test after 3 month. Amazing, it lost only 10% of its weight and it's ready to be extracted :

- Weight the result of each extraction :

- repeat with other specimens :

As an aside :
In order to get the ratio fresh weight/dry weight i did dry one of the cutting. It was Sample of #P3 :

Despined :

Cut in stars and drying :

Dry weight :

As you can see, dry matter if only 3,9% of the fresh weight but for future calculation i will take 5%.
Bunch of numbers:

The P# : Trichocereus Peruvianus started from seeds (between 2 and 3 years old).
The named (Katinka, Niño, Humberto) : cutting brought back from Peru and started to grow 2 years ago.
%fresh = ((extract)/(fresh weight))*100
%dry = (%fresh)/(5/100)
%3 month = ((extract)/(weight test+3 month))*100
gain in % =(((%dry test)/(%dry sample))*100)-100
Anecdotal evidence : Niño is the only one planted in the ground (shady area) and, so far, gave the best yield.
Any question is welcome.
Disclaimer : i'd like to think i have a scientist soul but in fact i lack rigor (e.g : i don't weight anything when i run an extraction) so all the results have to be taken with a grain of salt and if someone wants to run his own experiment, it's welcomed.
« I love the smell of boiling MHRB in the morning »