InTheShed Grows Inside & Out: Jump In Any Time

FelipeBlu · Oct 3, 2021

Thanks Maritimer! I have withheld watering/fertigating during the final week and have observed what seemed to be increased resin production, so I am interested enough to give this a try.

Maritimer said:
exposed to drought stress at week seven in the flowering stage

In the text from the study, it’s unclear to me if the drought stress is only during week 7 or continues until harvest. You appear to indicate that it’s continuous, which makes sense to me.

Maritimer · Oct 3, 2021

FelipeBlu said:
Thanks Maritimer! I have withheld watering/fertigating during the final week and have observed what seemed to be increased resin production, so I am interested enough to give this a try.

In the text from the study, it’s unclear to me if the drought stress is only during week 7 or continues until harvest. You appear to indicate that it’s continuous, which makes sense to me.

Hi Felipe,
The drought begins at start of week 7 and continues until a 50% change in LWA has been observed or 11 days later, whatever occurs first. I normally run at least 8 days before the plants tell me they have been stressed enough (greater than 50% change from turgid reading). If I still have active bloom (pistols) I resume normal fertigations until harvest. If the pistols have retracted, I just take her down straight from the drought.

FelipeBlu · Oct 3, 2021

Maritimer said:
continues until a 50% change in LWA has been observed or 11 days later, whatever occurs first. I normally run at least 8 days before the plants tell me they have been stressed enough (greater than 50% change from turgid reading).

By 7 weeks of flowering, I typically have to fertigate daily in perlite hempy. I would likely see 50% delta LWA within 3 days. So would I run several leaf wilt cycles until 11 days has passed, and then resume normal daily fertigations if the plant isn’t ready for harvest?

Moony · Oct 3, 2021

FelipeBlu said:
By 7 weeks of flowering, I typically have to fertigate daily in perlite hempy. I would likely see 50% delta LWA within 3 days. So would I run several leaf wilt cycles until 11 days has passed, and then resume normal daily fertigations if the plant isn’t ready for harvest?

At a certain point I do question whether this is even English anymore? Lol.

Don't forget the fertigations of the film flam with HLQ and 4 days worth of sniffle flops.

:ganjamon:

I'm assuming that the reason I understand non of this is that it is hydroponics related? Hehe

FelipeBlu · Oct 3, 2021

fertigate

(ˈfɜːtɪˌɡeɪt)
vb, -ates, -ating or -ated
(Agriculture) to fertilize and irrigate at the same time, by adding fertilizers to the water supply
[C20: from fertilize + irrigate]
ˌfertiˈgation n

Moony · Oct 3, 2021

I was right!!!! Words and things!!! Lol

Maritimer · Oct 3, 2021

FelipeBlu said:
By 7 weeks of flowering, I typically have to fertigate daily in perlite hempy. I would likely see 50% delta LWA within 3 days. So would I run several leaf wilt cycles until 11 days has passed, and then resume normal daily fertigations if the plant isn’t ready for harvest?

Sorry to say, but I do not think it will work out with your medium drying so quickly. The plant will not have enough time to process the environmental stress and begin hormonal changes. According to Dr. Kaplan repeated droughts are not the answer either, however the young doctor was not conducting the study in perlite. You may get some benefits from repeated wilt cycles and we can tune the process. You might, just might find this works. In mostly peat moss it is certain.

InTheShed · Oct 3, 2021

I'll get to this all later but I just wanted to make sure that @Moony knew we were talking soil and soilless here, not hydro. And also to be clear, soilless is not hydro, it's peat-based growing media...which is what I grow in.

I hope that clears some of this up!

FelipeBlu · Oct 3, 2021

THIS is the article, yes?

Yep, this study was soilless

Plants were transplanted into 11-L blow-molded black pots (279 mm diameter · 241 mm height) containing Pro-Mix HP Mycorrhizae (Premier Tech Horticulture)

InTheShed · Oct 4, 2021

So much to catch up on, here and all over the site! Let me get this quick Monday update out of the way so I can get to Maritimer's great post on drought-stress for increased cannabinoidation in the next post!

Yesterday I was tired of having the Sour G clone living in the solo cup, so even though it wasn't needing water every day, I transplanted it into a 1 gallon pot:

20211003_122534 Sour G clone transplant.jpg

InTheShed
Oct 4, 2021

Sour G upcan

20211003_123017 Sour G clone transplant.jpg

InTheShed
Oct 4, 2021

Sour G upcan

20211003_123144 Sour G clone transplant.jpg

InTheShed
Oct 4, 2021

Sour G upcan

It's in the shade for the next few days to lessen the transplant shock and then it needs to get moving!

I hope you all had a great weekend. It was hot and dry here as the Santa Anas blew through. :cool:

Drought info post below... ↓↓↓

InTheShed · Oct 4, 2021

Maritimer said:
A short essay on droughting cannabis.

Thanks for posting this here Maritimer! I'm going to drought the Sour G only, because in case everything goes horribly wrong I still want to be able to show off how well the Chiquita Banana from WSE did the old fashioned way. :cheesygrinsmiley:

Maritimer said:
Doctor Kaplan

The paper has it as "Caplan" for those trying to find it online.

Maritimer said:
“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 Drought had substantial effects on cannabinoid yield, expressed as grams of cannabinoid from floral material 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.”

Who wouldn't like a 12% increase in THCa for no work at all (other than the effort it takes to not water!)?

I was concerned that the increase in THC and CBD were a result of a decrease in the size of the buds, because if you don't water it, how can it bulk up in those final weeks. But the article states:
"...inflorescence dry weight did not differ statistically between the two treatments...These results suggested that the level of drought stress applied was adequate to stimulate cannabinoid production without reducing inflorescence dry weight for this cultivar."
so I think that means the buds weren't stunted! "Inflorescence" refers to the complete flower head of a plant including stems, stalks, bracts, and flowers.

StoneOtter said:
I've seen the light! Actually I've seen the trichs build during my droughting them. Wouldn't grow without doing it. And it's free!

Free!

FelipeBlu said:
By 7 weeks of flowering, I typically have to fertigate daily in perlite hempy. I would likely see 50% delta LWA within 3 days.

This is my concern as well given how quickly my plants dry out in ProMix HP. I'm sure Caplan's tests were run indoors in a controlled environment, as are Maritimer's. Yesterday my plants got watered in the morning and sat in the sun with air temps at 88ºF (I'm sure leaf temps were near 100º) and humidity in the 20s. This morning they were pretty light already.

Moony said:
I'm assuming that the reason I understand non of this is that it is hydroponics related?

LOL! As mentioned above, not hydro at all. :high-five:

Maritimer said:
In mostly peat moss it is certain.

Thanks for clarifying that!

Since I've started the drought period, I thought I would post some reference pics. Here is how Caplan diagrams the leaf wilt angle measurement:

LWA diagram.JPG

InTheShed
Oct 4, 2021

Leaf wilt angle diagram from Caplan's paper

And here are my lame attempts with a protractor on sagging branches!