Influencing sexual outcome of seedlings

[Entheo Shaman]

I was recently reading Marijuana Horticulture, the indoor/outdoor medical growers bible by Jorge Cervantes.

It states that there are several environmental factors can influence the sex of the seedling once the seedling has three sets of true leaves.

Those factors are:

Increased nitrogen makes more female plants. A higher nitrogen and lower potassium level for the fist two weeks increases females.

Lower temperatures increases the number of females.

High humidity increases females.

More blue light increases females.

Fewer hours of daylight (14 hrs) increases females.



I am wondering if anyone has any experience or thoughts on this. Also, wouldnt adding nitrogen to a seedling be dangerous to the health of the plant?

 

[BITYmagicBeanz]

I was recently reading Marijuana Horticulture, the indoor/outdoor medical growers bible by Jorge Cervantes.

It states that there are several environmental factors can influence the sex of the seedling once the seedling has three sets of true leaves.

Those factors are:

Increased nitrogen makes more female plants. A higher nitrogen and lower potassium level for the fist two weeks increases females.

Lower temperatures increases the number of females.

High humidity increases females.

More blue light increases females.

Fewer hours of daylight (14 hrs) increases females.



I am wondering if anyone has any experience or thoughts on this. Also, wouldnt adding nitrogen to a seedling be dangerous to the health of the plant?

use liquid nitrozyme.. or another good nutrients thta is nitro based.. either soak your jiffys or rockwool in it! or spray them. or add it too there regular water feed. most soil plants like nitorzyme. so its always best to add it like a supliment

 

[thcnology]

If you'll really look at those factors, you'll see that all Jorge is suggesting is giving the plants exactly what they need. IMO the single most influential factor is stress, more stress more males. The other thing not on that list is PH, in my experience a slightly lower PH will also promote more females from your seeds.

 

[howardtheduck]

dont be dumb

I'm no botanist, but i am pretty sure the single most important factor for determining a seedlings ultimate sex is genetics. You can cause hermaphrodite phenotype by stressing the plant various ways, but you can't change a female into a male or visa versa anymore then you can for any other organism. Drop a baby girl on its head and it grows a dick?

 

[Ulysses]

The methods posted above will significantly boost the number of females in a given run...

By significantly, I mean worth your time and efforts. That is, if you want females...

High nitrogen is to be in the fractional percent! Worm Castings tea works well when given for the first 3-4 weeks, at this stage, the plant needs little else...

 

[CrippledCrow]

The methods posted above will significantly boost the number of females in a given run...

By significantly, I mean worth your time and efforts. That is, if you want females...

I agree 100% and Ive follow those guides for a long time now , if you wanna try an experiment outdoors plant a bunch of seedlings on a hill top high and dry and a bunch in a valley low and wet from the same seedline and I gaurentee you`ll see a big difference in ratios , enviormental factors play a big role in sex ratios of seedlings.

 

[Cloud 99]

I'm no botanist, but i am pretty sure the single most important factor for determining a seedlings ultimate sex is genetics. You can cause hermaphrodite phenotype by stressing the plant various ways, but you can't change a female into a male or visa versa anymore then you can for any other organism. Drop a baby girl on its head and it grows a dick?

actually most animals born from eggs have thier sex decided by temperature so i have no reason to doubt Mr.Cervantes.if you think im dumb too then go search alligators

 

[keyplay]

actually most animals born from eggs have thier sex decided by temperature so i have no reason to doubt Mr.Cervantes.if you think im dumb too then go search alligators

My money is on the Cervantes guy. We love his bible-now if he could work on the disguise a little bit hehehehehehe:whew

 

[knottynuggs]

thcnology has the right idea i think... these are all things that you should be trying to do in the first place. ive never understood peoples 50/50 male to female ratio. most the time i cant get a male if i want one.

 

[howardtheduck]

i definitely am not a botanist

A quick glance over the literature leads me to believe that there are more environmental factors involved in sex determination then I previously indicated. It turns out that a number of things have been shown to increase the proportion of female to male flowers in an individual plant... causing hermies to show up if you stress the plant. C. Ainsworth reviews that treatment with auxin and ethylene have feminizing effects, and that treatment with cytokinins and gibberellins have masculinizing effects. That being said, I believe that good genetics in seeds will decrease the likelihood of environmental factors playing a role in sex determination. In other words, feminized seeds give high proportion of females to males regardless of environment because of strong genetic (XY system) influence in those strains.