Do any variables affect male/female ratio?

Recently I've had a bad run of males from regular seeds. It's happened on 4 different packs from a few different breeders (including one I've usually had great results from). I'm talking one female out of a 5 pack, one strain I didn't get a single female on a 5 pack. So what gives? I generally germinate via paper towel in a ziplock @ room temp unless it's winter in which case it sits on the cable box. Once sprouted they go into Roots soil straight out of the bag and veg under 110w flourescents. Does anything in the sprouting process affect what sex the seed turns out, or is it all genetically made up upon pollination, and decided no matter how the seed sprouts?

Honestly in my experience it has just been luck of the draw. Ive read from a couple different places that cool temps and high humidity (like 70 degrees and 70% humidity) help with the female ratio, but there have been times when Ive germed multiple packs from different breeders under those environmental conditions and some packs had high males counts as well as others having high female counts,so I figured it had no effect.

Grow fems.

I once had 8 out of a 10 plant run turn male. I couldnt freakin believe it. My last time 7 out of 8 turned female. ( I was looking to run about 4 plants)
So, I think it is just the luck of the draw. I've been running femenized lately for that reason. That way I'm not wasting lights, nutes, love etc on plants that are going to turn male.

this is from a book of mine "Marijuana HOrticulture the indoor/outdoor medical growers bible" - jorge cervantes..."environmental factors that influence sex determination of cannabis include but are not limited to: increasing the level of nitrogen makes more female plants. increase the level of potassium to increase more male tendencies; lowering the potassium level encourages female plants. a higher nirogen level and a lower potassium level for the first two weeks increase females. low temperatures increase the number of female plants. warm temps make more males. high humidity increases the number of female plants. low - males. low growing-medium moisture increases males. more blue light increases theh number of females plants. more redi light increases male tendencies. fewer hours of daylight (e.g. 14 hours) increase the number of females. longer days (18 hours) make more males. any stress results in more males so avoid re-potting often and changed soils.

Well, the only variable in your post 420 that would have been off is the vegetative light time, in that I usually veg for 20 on 4 off, so perhaps i have been just getting a lousy run on luck? Recently I saw that a couple others were getting 1 female out of a 5 pack on one of the same strains I had trouble with, so that specific one may be the line itself, I dunno? I'm kind of also getting to the point of running fem seeds exclusively, but I do enjoy a bit of phenotype variation sometimes. I also see a lot of great looking flavors that aren't offered feminized. Anyone else?

Just because it is in print does not mean it is true. Jorge has been the victim of misinformation too many times.

Feminized seeds make me believe that sex is predetermined in the seed.
How is it that 100% of the feminized seeds I have grown have been female?

That alone is enough evidence for me to believe that sex is predetermined in seeds.

This is a pretty good read about sex and cannabis seeds:
http://boards.cannabis.com/basic-growing/133478-almost-final-answer-what-determines-sex.html

There is also a company in Montana that can test a tissue sample of marijuana for sex even from a small seedling
I have not heard anything logical to lead me to believe that sex is not predetermined in cannabis seeds.

Feminized seeds for the win.



In my opinion, cannabis tends to produce more females than males naturally. I have no evidence for this other than my experience.