I just made a post, and it got me to thinking after I posted it. I was posting in a thread where he was bitching about getting all males, and rightfully so. I'd be pissed if that happened to me too.
My post included a quote from dutch passion seed company that says:

From literature and our own findings it appears that the growth of a male or female plant from seed, except for the predisposition in the gender chromosomes, also depends on various environmental factors. The environmental factors that influence gender are:

* a higher nitrogen concentration will give more females.
* a higher potassium concentration will give more males.
* a higher humidity will give more females.
* a lower temperature will give more females.
* more blue light will give more females.
* Fewer hours of light will give more females.

It is important to start these changes at the three-pairs-of-leaves stage and continue for two or three weeks, before reverting to standard conditions.

What got me to thinking was the line that said: Fewer hours of light will give more females. The reason I point this out is, I've seen a few debates recently about 18/6 lighting vs 24/0 lighting.

If the above paragraph is correct and true, wouldn't 24/0 produce more males?

I hope not, i always here people going with 18/6 to save on the bill and that 24 is better, when i grow im gonna use 18/6 for money saving. So all in all. if 24 does give more males than 18/6 is the best way to go.

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Using 16/8 on the past grow about 80% turned out to be female. That is even less lighting then the 18/6. Maybe a connection there?

Someone should do a grow test where 10 random seeds are in 16/8, 18/6, and 24/0 using everything else exactly the same besides the lighting hours to see which ones produce more females and males (same lighting, ventilation, bulbs, etc.) Anyone up to the task? I would, but no room and broke as shit lol.

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Well from that quote, I'd say yes, that 24/0 would produce more males. 24/0 is definately not the way to go. The dark cycle is very important for plant growth as it causes stronger root development which means stronger, bigger, healthier plants. I always go with 18/6. So with 18/6 you would have a better root system, and better chance of females. Is there any reason at all to go 24/0??

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I alsways used 24 hour floros for new seedlings and have about 80% female production as long as I use good seed.Now with bag seed its a crap shoot anyway you slice it.My babies stay 24 hours for at least 2 weeks then 2 weeks 18/6 (maybe more if I want bigger plants) then 12/12 for flower.

i am using 24/0 on my new clones as my timer blew it,s arse,it has only been a few days,but have never done it before,so of to get a new timer this weekend when i head into the big smell to get my supplies for the month,so hope no hermies,but i always figure every living thing needs to sleep,but lots say they do use 24/0 not my scene though?

So if I use the 16/8 light setting untill they flower, then drop them down to 12/12 I should get some pretty damn good buds right? Im still a little new to the way im doing this. Never used seeds before untill now.

AssGasOrGrass, I never heard that 24/0 was better. I have heard arguments on both sides of the fence, however I have always felt it is best to try to mimmick mother nature. So it's 18/6 for me.

PaulioJr, your results are exactly what they are saying to do: "Fewer hours of light will give more females." Using 16/8 was smart.

I have a friend who uses these guidelines on all grows, and claims a 90% ratio of females.

Yeah exactly i think the whole point of indoor growing is to try to mimmick mother nature.

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I dont know this for sure yet but i've had similar thoughts. I had my lights on 24/7 for the sprouts into the first week of growth but aborted the idea in favor of strong healthy root growth.

I think its feasable.