Register ICMag Forum Menu Features Search Today's Posts Mark Forums Read
You are viewing our:
in:
Forums > Marijuana Growing > Cannabis Botany and Advanced Growing Science > 24 Hours Of Dark before switch to flower

Thread Title Search
Post Reply
24 Hours Of Dark before switch to flower Thread Tools Search this Thread
Old 01-13-2019, 01:16 AM #31
Ibechillin
Member

Ibechillin's Avatar

Join Date: Jun 2017
Location: Tacoma, Washington 47n
Posts: 778
Ibechillin has much to be proud ofIbechillin has much to be proud ofIbechillin has much to be proud ofIbechillin has much to be proud ofIbechillin has much to be proud ofIbechillin has much to be proud ofIbechillin has much to be proud ofIbechillin has much to be proud ofIbechillin has much to be proud ofIbechillin has much to be proud ofIbechillin has much to be proud of
I found a better explanation of phytochrome red/far red and wanted to share to help explain it better and clear up any confusion:

The phytochromes are a family of chromoproteins with a linear tetrapyrrole chromophore, similar to the ringed tetrapyrrole light-absorbing head group of chlorophyll. Phytochromes have two photo-interconvertible forms: Pr and Pfr.

Pr absorbs red light (~660nm - ~729nm) and is immediately converted to Pfr.

Pfr absorbs far-red light (~730nm - ~800nm) and is quickly converted back to Pr.

Pfr naturally converts to Pr in darkness over time.


Absorption of red or far-red light causes a massive change to the shape of the chromophore, altering the conformation and activity of the phytochrome protein to which it is bound. Pfr is the physiologically active form of the protein; therefore, exposure to red light yields physiological activity. Exposure to far-red light inhibits phytochrome activity. Together, the two forms represent the phytochrome system.



Unfiltered sunlight is rich in red light but deficient in far-red light. Therefore, at sunrise, all the phytochrome molecules in a leaf quickly convert to the active Pfr form, and remain in that form until sunset. In the dark, the Pfr form takes hours to slowly revert back to the Pr form. By sensing the Pr/Pfr ratio at sunrise, a plant can determine the length of the day/night cycle. In addition, leaves retain that information for several days, allowing a comparison between the length of the previous night and the preceding several nights. If the night is long (as in winter), all of the Pfr form reverts. If the night is short (as in summer), a considerable amount of Pfr may remain at sunrise.

Link to source:


https://courses.lumenlearning.com/iv...nses-to-light/

So to clear up any confusion:

Its the ratio of how much time either Pr or Pfr is the active phytochrome that dictates the flowering response in short day plants like cannabis.

Red light between 660nm - 729nm converts Pr in the plant to Pfr which helps the plant remain in veg.

Infra red light between 730nm - 800nm converts Pfr in the plant to Pr which helps the plant begin flowering.
__________________
Quote:
Originally Posted by Dirt Bag View Post
The beauty of science is that it works whether you believe in it or not. - NdT
Quote:
Originally Posted by Ibechillin View Post
Sadly Pseudoscience works the same way, and dunning kruger aint helping much either...
The Science Of Grow Lighting (HPS, CMH, LED) & Photosynthesis Explained: (Sticky Thread)
https://www.icmag.com/ic/showthread.php?t=358147

The Drying and Cure Process Explained In Depth, Information On Long Term Preservation: (Sticky Thread)
https://www.icmag.com/ic/showthread.php?t=358186

Tons Of Information On Growing, Root Systems and Breeding:
https://www.icmag.com/ic/showthread.php?t=344347

Silicon, The Misunderstood Element.
https://www.icmag.com/ic/showthread.php?t=352413

Tons of information on Humic/Fulvic acid and sources:
https://www.icmag.com/ic/showthread.php?t=352265

HOW TO GET 1.5+ GRAMS PER WATT!:
https://www.icmag.com/ic/showthread....330588&page=29

A Guide On When To Plant Outdoors & Force Flowering:
https://www.icmag.com/ic/showthread.php?t=352312


Last edited by Ibechillin; 01-13-2019 at 01:32 AM..
Ibechillin is offline Quote


2 members found this post helpful.

Post Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


All times are GMT +2. The time now is 07:22 AM.




This site is for educational and entertainment purposes only.
You must be of legal age to view ICmag and participate here.
All postings are the responsibility of their authors.
Powered by: vBulletin Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.