Uhgg... it's a "Sausage Fest" in there!

[cheyenne]

Here are two to check out:



http://www.nature.com/hdy/journal/v88/n2/full/6800016a.html

It gets a bit complicated since cannabis is a genotypically intersex species. It is also important to differentiate between environmental influences when the seeds form (which do appear to influence sex ratios) and environmental influences when the plant is growing (which do not appear to influence sex ratios.)

Charles Xavier has a really good answer to this question on another thread:

"Sexual determination is genotypic. That means it is written in the genetic code of the organism. Whether it is 'male' or 'female' is predetermined.

Sexual expression is phenotypic. That means all the traits possessed by an organism that can be visually observed; but it also encompasses all the traits that can be made to manifest by manipulation or stimuli. Whether it appears to be 'male' or 'female' is condition dependent.

The environment does not "trigger the sex gene". The sex of the plant is already fixed. The environment influences expression i.e. causes certain chemical processes in the plant that may cause it to look differently.

The genetic code (genotype) remains intact, but what can be visually assessed is influenced by the environment (phenotype).

Here's the deal: ordinarily the environment shouldn't have such a profound effect on a seed, but irrespective of what they appear to be phenotypically, most Cannabis plants are genotypically intersex specimens (colloquially referred to as hermies).

That's just the way it is.

Sincerely,

Charles."

Or in other words, sex is determined by genetics, period. Environment simply does not influence genetics except in extreme examples.

Awesome thanks for those links. I always appreciate it when people can substantiate claims. Much obliged.


FJ, that is my take as well and what i was refering too in my 1st response. I think i picked that up back in the early 90's from Ed's books.....4" min for the tap root. I speak from my experience, albeit limited from seed starts as ive been fortunate to work with clones only for most of the last 15 years or so. But when i was doing alot of seed starts, i always gave the 4" and blue light and ALWAYS got a higher % of females. It may be an OWT but hey.....Ill keep on doing it!

 

[farmerjohn]

Sound advice, as usual, cheyenne. My slant on this is that sex probably is predetermined, but other factors, perhaps many, can & do influence the outcome. As always, the proof is in the pudding. While my seed starting experience is limited too, I can say that one factor seems to influence survival rate percentage & female/male ratio. When I start seeds in peat pellets or other small seed starter pots, the survival rate goes down & the male to female ratio goes up. When I plant directly into 6" tall, half gallon containers, the reverse has always been my experience. I've learned my lesson the hard way. My precious seeds go into big ass pots! I don't have the smarts to totally decipher some of the technical jargon I read, But I do have the savvy to know the difference between 75% female & 25% female!

 

[rhead]

well... Im gonna pop these super skunks tomorrow, added 6,000 btu ac, going strainght into 3 gallon smart pots full of Foxfarm Ocean Forest Soil. I just have good luck with the Foxfarm stuff so imma stick with it. Thanks for all the school'n!

:bong2:

 

[cheyenne]

Add 25% perlite to the FFOF. Maybe a teaspoon of gardeners lime.

 

[The Joker]

What an interesting read Rhead ( no pun intended).

Another marijuana myth debunked. I've heard that environment determines sex a lot.

I once grew two packs of seeds SD "IBL" and Williams Wonder. The SD gave me 9 males. At the same time, in the same place.
The WW gave me 5 out of 6 females. Rez told me it was my environment even though there were many ( deleted) reports of high male rates.

I think it's just law of averages. I did an open pollination with some males and the female and made seeds and gave them all away.

 

[BUDOGHI]

rhead,
for starting seeds with fox farm I like to mix 1/2 light warrior with 1/2 ocean forest. the light warrior brings in quite a bit of perlite and opens up the mix, I usually add some worm castings too but not necessary.

 

[TortureKill]

Work on lowering your temps. If you are hitting 90 degrees during germ/veg, its "said" that higher temps lead to more males and vice versa- so keep it cooler during germ (70's) and hopefully you can have better female ratio. And to help with heat, you shouldn't need 2 (600)'s for vegging. Take a look at a smaller veg light or add a few more cfl's. You don't need much light for vegging, and that will help drop temps considerably til flowering. Then at that point I suggest improving exhaust/airflow to get the temps down.....

If space is limited, consider looking into feminized seeds, but as they can herm make sure your environment is consistent and a slightly cooler to avoid any possible issues.

Don't know where you live but a garden center or Hydro store might have some higher quality soil,would be good to try and find some Fox Farm,Roots Organic,or Black Gold.
Scrimping on soil is not the best item to try to get on the cheap
starting out!

Solid Advice fellas.

 

[gudkarma]

interesting.

a little late to the discussion... but i just read this the other day.

http://www.invalid.com/advanced-marijuana-cultivation/95992-increasing-odds-female-seeds.html