I know there have been a few topics on how to achieve a higher female percentage, but here is an article that had a few more conditions added to it. Check it out courtesy of cannabis-seed-banks.com

PERCENTAGE OF FEMALES
From literature 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. For growers who are well experienced, percentage of female plants is 60% - 90% female, but less experienced growers can end up with 100% male plants. The environmental factors that, according to literature, influence gender are:

- a higher nitrogen concentration will give more females (at the three-pairs-of-leaves stage and continue for two or three weeks).
- a higher potassium concentration will give more males (at the three-pairs-of-leaves stage and continue for two or three weeks).
- a higher humidity will give more females (at the three-pairs-of-leaves stage and continue for two or three weeks).
- a lower temperature will give more females (at the three-pairs-of-leaves stage and continue for two or three weeks).
- more blue light will give more females (at the three-pairs-of-leaves stage and continue for two or three weeks).
- Fewer hours of light will give more females (at the three-pairs-of-leaves stage and continue for two or three weeks).
- In later stage, as you increase the light, the plants grow faster and show more females/less males. Sixteen hours of light per day seems to be the best combination, beyond this makes little or no appreciable difference in the plant quality.
- Another idea is to interrupt the night cycle with about one hour of light. This gives you more females.
- Spray dilute Fish Emulsion ( 1 tablespoon per gallon ). When the plants have three sets of true leaves, plus the top sprout, give them a wetting spray of Fish Emulsion. Do it once a day for three of four days. Top and bottom of the leaves.
- To achieve 100% female plants is to expose young seedlings for several hours to an atmosphere of Carbon Monoxide. It doesn't hurt the plants, but it could kill you.
- Treatment of hempseed with ethylene gas will increase the resulting number of female plants by about 50%. Ethylene is produced by certain plants (i.e., bananas, cucumbers and melons), and these can be used to treat hempseed in a simple manner. About two weeks before you plan to sprout the seeds, place them in a paper bag or envelope and put that in a plastic bag with the peels of a ripening banana or cucumber. Replace the peels after a couple of days, and change the bags to prevent mold.
- When hempseed is treated with the female hormone estrogen, percentage of females that are produced will increase by about 10%. Dissolve a birth control pill in water and soak the seeds overnight in the solution. After the initial soaking, continue to treat the seeds by sprouting them on a paper towel soaked in the solution.

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USEFUL LINKS

Marijuana Light Spectrum
Higher Female Ratio
Foliage Feeding
Drying & Curing Marijuana
Grow Room Ventilation
Usefullness of Males

From literature it appears... I wonder where they got their information from? It doesn't sound too convincing starting an informative article in this way. It's almost as though they themselves do not have full belief in their information.

Also, less experienced growers can end up with 100% males. wtf are you talking about? Was that even in the article?

Experienced growers on this site have had nearly these kind of results. It's about genetics.

Also what's the part about a seeds predisposition? This means that the seed is predisposed to be a certain sex... which means that in all likelyhood, despite whatever environmental factors/changes you introduce the plant will turn out the sex it was meant to be.

To my mind, by fucking around like this you are merely increasing your chances of getting hermies.

i have rea dabout this debate a lot lately. weeds are adaptable by nature. its how they survive. im sure environmental factors could have some effect. if a fish or amphibian can change sex from its "predestined" sex, why couldn't a weed? when you rely on wind and other variables to find you a place to live, you had better be adaptable.

when? what stage? and how does this work or make sense?

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- durban poison x skunk #1 & california orange

haha. i thought that was funny.

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- durban poison x skunk #1 & california orange

Just to make this (almost pedantic) point, weed is not a weed it is a plant. It is likened to weed because of it's very distant relationship to the nettle and it's hardy nature. I mean you wouldn't spray weed killer on your plants and then expect them to grow back would you?

We're talking about cannabis, not a type of fish (as not all change sex do they) or amphibian (neither does all types of amphibian). We're talking about cannabis.

All things that survive are adaptable by nature, or they wouldn't survive. They'd join the ranks of the extinct.

Also the word I used was predisposition, why have you speech-marked the word predestined when this was not the word I used. That's like quoting me and replacing it with your own wordage. Insulting. Maybe, it's just your ignorance.

You've read a lot on this debate, have you? Well you need to go and read a lot more.

who's going to try this experiment?

100% females, eh. Fuck the fuck off.

whats wrong with just growing multiple plants - kill the males and clone the females? doesnt that in essence acheive 100% female plants.

sure it sucks if you get all males, but perhaps karma would be at work with such a travesty

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"Any society that would give up a little liberty to gain a little security will deserve neither and lose both." - Benjamin Franklin. Answers can always be as likely to be found in the past as they are to be found in the future.

MR P can you get your hands on any female estrogen or any bc pills . i dont think me missus would like for me to start asking the opposite sex (lovely ladies) for these..LOL thanks....chuck. with everybody help i'll have me a harvest from hell.