Droughting and its medicinal effects in cannabis

[Krissi Carbone]

Hope it's just a flu bug. Nasty one been running through our house for over a month now. All the hallmarks of covid, but test came back negative.
Either way, I hope you all feel better

I hope so too, while he was laying on the couch feeling like crap, I decided to set up the Candy Factory tent and light so hey, I guess there's a silver lining to everything!

 

[StoneOtter]

Remember this isn't heresy.

 

[Krissi Carbone]

Remember this isn't heresy.

You liked that, huh... I may be a strega but this isn't witchcraft!

 

[nivek]

heya friend,, curious if you can or have posted a link to any science you have on this subject,,

many thanks

to be honest,, tho i looked a bit,, i could not even find an explanation as to what droughting even is, or how to do it,, tho i am great at assumptions

 

[Krissi Carbone]

heya friend,, curious if you can or have posted a link to any science you have on this subject,,

many thanks

to be honest,, tho i looked a bit,, i could not even find an explanation as to what droughting even is, or how to do it,, tho i am great at assumptions

Increasing Inflorescence Dry Weight and Cannabinoid Content in Medical Cannabis Using Controlled Drought Stress

Controlled application of drought can increase secondary metabolite concentrations in some essential oil-producing crops. To evaluate the effects of drought on cannabis (Cannabis sativa L.) inflorescence dry weight and cannabinoid content, drought stress was applied to container-grown cannabis...

journals.ashs.org

I haven't gotten into the art of it. I gave a basic synopsis somewhere back here, at around 7 weeks of flower you drought your cannabis. You will do this for 11 days. Throughout this time you take angle measurements as your leaves droop. Once the leaves wilt to 50%, you begin feeding again. That is a short breakdown...

The numbers on the introduction of this journal are from the controlled experiment

 

[Cactusreefer]

Thank you for this! I am currently reading @Maritimer rezination journal, almost halfway. Great stuff in there. Will read this when I finish. Thanks!

 

[Krissi Carbone]

Thank you for this! I am currently reading @Maritimer rezination journal, almost halfway. Great stuff in there. Will read this when I finish. Thanks!

Smart move! Finding his Rezination journal changed the way I grow. Enjoy it!!!

 

[nivek]

Increasing Inflorescence Dry Weight and Cannabinoid Content in Medical Cannabis Using Controlled Drought Stress

Controlled application of drought can increase secondary metabolite concentrations in some essential oil-producing crops. To evaluate the effects of drought on cannabis (Cannabis sativa L.) inflorescence dry weight and cannabinoid content, drought stress was applied to container-grown cannabis...

journals.ashs.org

I haven't gotten into the art of it. I gave a basic synopsis somewhere back here, at around 7 weeks of flower you drought your cannabis. You will do this for 11 days. Throughout this time you take angle measurements as your leaves droop. Once the leaves wilt to 50%, you begin feeding again. That is a short breakdown...

The numbers on the introduction of this journal are from the controlled experiment

study looks interesting, indeed, thanks

 

[Krissi Carbone]

study looks interesting, indeed, thanks

Thank you for the open mind friend. Cheers to your new year coming

 

[nivek]

study conclusion

This study suggested that controlled drought stress can increase the concentration of the major cannabinoids THCA and CBDA and the yield of THCA, CBDA, THC, and CBD in chemovar II cannabis without reducing inflorescence dry weight and irrespective of decreased Pn. These results were achieved by gradually drying the substrate over 11 d until plant WP reached approximately −1.5 MPa during week 7 in the flowering stage. Comparable results can be expected using leaf wilting as a drought-stress indicator with fertigation triggered at a leaf angle 50% higher than in its turgid state. This method for administering drought stress and the results of this study should be applicable for similar varieties of chemovar II cannabis; however, other chemovars or varieties may respond differently.

edit,, the time line is confusing me,, does not add up

54 days in flower, then harvested,,,,,,

drought period of 11 days starts week 7, so day 43 i guess?

11 days drought starting day 43,,

finishes drought at harvest day, day 54,, more research needed,, but not a long study at all

hmmmm, and, how to achieve this idea in a hempy grow,, hmmmm

 

[Stunger]

Thank you for this! I am currently reading @Maritimer rezination journal, almost halfway. Great stuff in there. Will read this when I finish. Thanks!

Great stuff indeed, I fully agree with you there. @Maritimer has made a great contribution sharing his experiments and knowledge of rezination. And many thanks too, to @Krissi1982 for her efforts here!

 

[Krissi Carbone]

study conclusion

This study suggested that controlled drought stress can increase the concentration of the major cannabinoids THCA and CBDA and the yield of THCA, CBDA, THC, and CBD in chemovar II cannabis without reducing inflorescence dry weight and irrespective of decreased Pn. These results were achieved by gradually drying the substrate over 11 d until plant WP reached approximately −1.5 MPa during week 7 in the flowering stage. Comparable results can be expected using leaf wilting as a drought-stress indicator with fertigation triggered at a leaf angle 50% higher than in its turgid state. This method for administering drought stress and the results of this study should be applicable for similar varieties of chemovar II cannabis; however, other chemovars or varieties may respond differently.

edit,, the time line is confusing me,, does not add up

54 days in flower, then harvested,,,,,,

drought period of 11 days starts week 7, so day 43 i guess?

11 days drought starting day 43,,

finishes drought at harvest day, day 54,, more research needed,, but not a long study at all

hmmmm, and, how to achieve this idea in a hempy grow,, hmmmm

There has been many thoughts of how to mimic in in DWC even.....I'm sure there is a way....

Great stuff indeed, I fully agree with you there. @Maritimer has made a great contribution sharing his experiments and knowledge of rezination. And many thanks too, to @Krissi1982 for her efforts here!

He has brought a profound light to medicinal cannabis and our ability to grow it. I'm forever indebted to his work

 

[Cactusreefer]

Great stuff indeed, I fully agree with you there. @Maritimer has made a great contribution sharing his experiments and knowledge of rezination. And many thanks too, to @Krissi1982 for her efforts here!

Agreed, thank you!!

 

[nivek]

There has been many thoughts of how to mimic in in DWC even.....I'm sure there is a way....

yes,, certainly some degree of drought conditions can be incorporated into any grow,, perhaps a couple of shorter droughts in a row in my hempy,, i have a couple of sativas in veg right now,, same plant, same age, a couple of weeks from flower,,

might be an idea indeed,, a side by side somehow,,

 

[Krissi Carbone]

yes,, certainly some degree of drought conditions can be incorporated into any grow,, perhaps a couple of shorter droughts in a row in my hempy,, i have a couple of sativas in veg right now,, same plant, same age, a couple of weeks from flower,,

might be an idea indeed,, a side by side somehow,,

Did you see that you tube video I posted? Years before the study was even conducted, couple Hippie growers been droughting for years...theirs are outdoor massive plants...they say they drought for 3 days...

 

[nivek]

Did you see that you tube video I posted? Years before the study was even conducted, couple Hippie growers been droughting for years...theirs are outdoor massive plants...they say they drought for 3 days...

nothing hasnt been tried,, indeed,, however,, i am not sure what this study would find after droughting for three days,,

some perhaps,, logic might suggest that any impact on the buds at that point would be just beginning to occur

key info here,

The drought treatment elicited a 12% increase in THCA concentration and a 13% increase in CBDA concentration but had no effect on the concentrations of the other detected cannabinoids (Table 3, top). Drought had substantial effects on cannabinoid yield, expressed as grams of cannabinoid from inflorescences per unit growing area (g·m−2). In the drought treatment, THC yield was 50% higher, THCA yield was 43% higher, CBD yield was 67% higher, and CBDA yield was 47% higher than in the control (Table 3, bottom).

edit 2,, i gotta figure out if they stop watering all together or reduce watering,,

 

[Rexer]

study conclusion

This study suggested that controlled drought stress can increase the concentration of the major cannabinoids THCA and CBDA and the yield of THCA, CBDA, THC, and CBD in chemovar II cannabis without reducing inflorescence dry weight and irrespective of decreased Pn. These results were achieved by gradually drying the substrate over 11 d until plant WP reached approximately −1.5 MPa during week 7 in the flowering stage. Comparable results can be expected using leaf wilting as a drought-stress indicator with fertigation triggered at a leaf angle 50% higher than in its turgid state. This method for administering drought stress and the results of this study should be applicable for similar varieties of chemovar II cannabis; however, other chemovars or varieties may respond differently.

edit,, the time line is confusing me,, does not add up

54 days in flower, then harvested,,,,,,

drought period of 11 days starts week 7, so day 43 i guess?

11 days drought starting day 43,,

finishes drought at harvest day, day 54,, more research needed,, but not a long study at all

hmmmm, and, how to achieve this idea in a hempy grow,, hmmmm

To do it in hempy is totally plausible IMO.
You would basically be replicating the way I did it with hydroton.
The key is to monitor the leaf wilt angle. Disregard the number of estimated days for the drought. Once you've hitten the Leaf Wilt Angle to indicate the drought is over, fertigate.

I marked a spot on my scrogg net, then took photos daily using an app to figure out the Leaf Wilt Angle. The key is consistent photos to make sure your angle measurements aren't skewed.

 

[nivek]

The key is to monitor the leaf wilt angle. Disregard the number of estimated days for the drought. Once you've hitten the Leaf Wilt Angle to indicate the drought is over, fertigate.

i dont agree with this yet

the length of time is key, imo, so far

 

[Krissi Carbone]

nothing hasnt been tried,, indeed,, however,, i am not sure what this study would find after droughting for three days,,

some perhaps,, logic might suggest that any impact on the buds at that point would be just beginning to occur

key info here,

The drought treatment elicited a 12% increase in THCA concentration and a 13% increase in CBDA concentration but had no effect on the concentrations of the other detected cannabinoids (Table 3, top). Drought had substantial effects on cannabinoid yield, expressed as grams of cannabinoid from inflorescences per unit growing area (g·m−2). In the drought treatment, THC yield was 50% higher, THCA yield was 43% higher, CBD yield was 67% higher, and CBDA yield was 47% higher than in the control (Table 3, bottom).

edit 2,, i gotta figure out if they stop watering all together or reduce watering,,

It was a complete drought in the study from my understanding, I would check @Rexer And his comment for info on your hempy drought, he has been the closest to do it in DWC so he's the man

 

[nivek]

but i am 2 hrs into reading this,,

fine science tho,, love it