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How many hours of light do I need for veg growth?

Leary

New Member
In the book Marijuana grow basics (by Jorge Cervantes) it says that "Seedlings that receive 16 hours of light and 8 hours of darkness tend to grow more female plants."

I thought that was pretty interesting so I thought I would share it here. I have decided to try this for myself and see how many females I get. I believe I am going to start off with 12 seedlings and see how many become females out of those. I will report my results once they have all been switched to 12/12 (it may be a while as I have yet to complete my grow setup).
 

Brett2theMax

New Member
Yeah I was real high when I read that I think faderharley, most people label the diurnals with the light period first / dark period second. So 14/10 confused me. I've heard of people extending the dark period before, I hear it slows down growth to shorten the day. I've been wanting to try a 16/12 light/dark cycle for a grow, I've heard of this being done for flower and since the cannabis plant can photosynthesize for 16 hours with out the rate of photosynthesis diminishing it should produce stronger results in flower. I just gotta buy digital timers.

Leary I've read that book before and its pretty awesome. Although when I read it I noticed he would just say that the optimal conditions produced more females with no real explanation just that it did. Its a great book don't get me wrong, but some of the facts in there I feel could be just to convince people to grow a certain way. The next 10 years are really going to rocket forward in the study's and writings of cannabis since so many people are living in compassionate states now, research can finally be done in a professional scientific environment where lots of data can be collected.
 

puzzu

New Member
i have 9 plants 1 week old onder a 1000w mh light 18/6 .how long i leve them in vegetative stage . ???
 

Captain Kronic

Member of the Month: July 2011
I would really like to know how that turns out... I read the same thing but have yet to try any of it out... cheers!

In the book Marijuana grow basics (by Jorge Cervantes) it says that "Seedlings that receive 16 hours of light and 8 hours of darkness tend to grow more female plants."

I thought that was pretty interesting so I thought I would share it here. I have decided to try this for myself and see how many females I get. I believe I am going to start off with 12 seedlings and see how many become females out of those. I will report my results once they have all been switched to 12/12 (it may be a while as I have yet to complete my grow setup).
 

faderharley

New Member
i have 9 plants 1 week old onder a 1000w mh light 18/6 .how long i leve them in vegetative stage . ???
Once again depending on the strain, but my 1st grow I had vegged for 9 weeks.... 2nd and 3rd grow 5 weeks. Once you switch to flowering or 12/12 light scedule, the plant will continue to stretch and grow for a few more weeks or until the colas really start to fatten up..... light schedule I use:

24/7 on vegging
flowering: 12/12 for 2 weeks or until I see pistil hairs, then I switch to a 10/14 light schedule for 10 days or up to 2 weeks as the flowers start showing.... apparently going dark for 14 hours per day creates more flowers.... then I go back to 12/12 for 3-4 weeks, then 10-14 days before the cut, I switch to 8/16 light schedule, this enhances bud maturity, ripening, additional trichome or resin production.... 2 days b4 the cut I go 48 hours of darkness to increase even more resin, it works for me....
 

D3vin77

New Member
I have a small plant in a cup in my room. Im new to this and dont see it producing any product. But its pretty cool. Id rather grow pot in science class than peas lmao. If anyone has any advice id appreciate it :D:peace:
 

Spicy2na

New Member
It's no doubt! Along with the diminishing light schedule, it looks like my girls are in a hurry to make love to my lungs!
 

The303Stoner

New Member
I have a small plant in a cup in my room. Im new to this and dont see it producing any product. But its pretty cool. Id rather grow pot in science class than peas lmao. If anyone has any advice id appreciate it :D:peace:
get a cloth grow pot :thumb:
 

Kushwestcoast

New Member
Hay Smokey,

Here's some other thinking:

From Chronic Chrissy

" Light Cycles

The dark cycle is very inportant to palnts. Respiration (this is when plants are making energy from sugar to oxygen) Continues in dark but at a much slower pace, almost independent of available oxygen because the leaves are not making oxygen in the dark.

In the dark there is a shift from leaf production to root production as the leaves transfer excess energy down to the branches and roots. Therefore, some dark time allows for better root structures. The "Experimental Root Growth 10 Days After Cutting" graph on page 33 shows that giving plants a 24-hour light cycle is not the way to supercharge growth"

This is from "How to supercharge your garden" With the graph on page 33 this follows...

"Light period for cuttings

Plants have a free running internal bio-rhythm of 21-27 hours. In this rhythm, they need dark time. Cuttings have a built in daily rhythm (age also) that they inherit from their parent. Cuttings will root better with a 6 hours to 8 hourdark period because this is the main time when leaves and the stems transfer energy down to the root zone for storage and growth."

The chart has hours of light per day on the bottom, and length of roots in millimeters.
-@ 4hours of light the roots after ten days were only 22mm long
-@ 8 hours of light after 10 days the roots were 25 mm long
-@12 hours of light we shoot up to 40mm long
-@16 hours it peaks at 50mm
-@20 hours it drops down to 37mm
-@ 24 hours it drops down to 29mm

There is also a shitload of info regarding root to yeild ratio vs veg to yield ratio, and draws the conclusion that at the end of the experiments the root to yield ratio was higher
__________________ "

:peace:
Haha i just had an argument about this exact thing with my buddy.
 

donpaul.p

Member of the Month: Aug 2013
Haha i just had an argument about this exact thing with my buddy.
im sure i was in on that argument, in fact im sure i started it, n thats y i ended up in this section, im reading all i can bout this lights schedule
 

sjdizzy

New Member
new to this but long time toker

i have to plants in the same dirt they are both the same age three weeks old should i keep them under 24/7 light for how many weeks ????
 

Smokemupm8

New Member
Hey everyone hope we all baked in here;) LOL.. Anyways, Im for 24/0 for seeds, til she has her 4th level of fan leaves-or 5 fingers each,(and is in her final pot) and then switch to 20/4 for few weeks.. for reasons IMO: save sum $, rest my equip for while and plants naturally get some dark time so i like to start it with 4 hrs for few weeks, then ill drop to 18/6 til i flower her. . As plants age they produce hormones etc; to stimulate growth, Ive read in a few well known growers journals, and books, that plants produce these growth hormones during darkness. And also ppl saying they give their plants 48 hrs b4 harvest is another reason for that theory. Tho im not 100% sure on the 48 hrs dark but anyway.. HorseBad has an interesting thread there, im all for having great root system for my plants-i use a product called Seaweed Extract that says it aids root growth and flower/fruit development, my last girl in a 25 litre pot basically ate the soil in the pot and there was a mass of nice healthy white interconnected roots.. She let me know when she was thirsty as the roots were only MM's from surface and she drank sum water! So im hoping to have similar this time as i have made preps for that. Goodluk mate, and Happy Harvesting;):thumb:
 
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