# increasing odds of female seeds



## bonz (Aug 3, 2008)

well i geusse i will eat my words on the fact that environment wont effect male female out come. haven`t tried this yet but i think it deserves a try at least.











Dutch Passion released an essay on how to increase mostly females from a pack of seeds. This is an excellent piece of work and has helped me to gain more of an interest in this area. In the past few years I have come to develop my own systems to get those ratios on the up and up. Right now I am very happy to report a real increase in my females from standard seeds. Sometimes as high as 90% to 95% on a consistent basis. So how is it done? 

I prefer standard seeds for numerous reasons. The first reason being that feminized seeds come from hermie plants. Whichever way you look at it, the specially treated plants are hermed and this trait is often expressed in the offspring where conditions are less than optimal. Even with standard seeds the hermaphrodite condition is still achievable where stress occurs. I seem to have noticed that the two most stressful conditions which can cause the hermaphrodite trait occur before flowering in the vegetative phase of growing is around the 3rd to 4th week of growth before pre-flowering when the plant undergoes either heat stress or a problem with the 24/0 or 18/6 photoperiod (whatever vegetative photoperiod choose doesn&#8217;t matter, as long as disruptions occur). Even during the initial stages of calyx development males and females are obvious side by side at the node region. This is hermaphroditism due to vegetative growth problems. In the flowering period, hermaphrodites generally occur quicker because of an irregular photoperiod than anything else and heat stress certainly helps bananas to pop up in with the bud. Now, even Sinsemilla crops will herm towards the end depending on the strain. I don&#8217;t class this as a typical case of hermaphrodites. It is just something that some strains naturally do towards the end of the Sinsemilla procedure. 

Anyhow for starters we better reproduce what Dutch Passion have to say about there feminized seeds first. 

"Feminised Cannabis Seeds" 

Courtesy of Dutch Passion 

In November 1998 we introduced our "Female Cannabis Seed". We did this after our own experiments showed that from female seed, we acquired almost 100% female off-spring. 

In the meantime we are six months further on . We have received a lot of feed-back from our customers. The reactions are mostly positive, clients who have successfully produced almost 100% female off-spring. However there have been reactions from customers who found a few hermaphrodites or males plants. Apparently environmental influences affect the sex of the female seeds as well. Because of the fact that Female seeds do not grow into female plants under all circumstances, we changed the name from "Female Cannabis Seeds" into "Feminised Cannabis Seeds". 

From literature and from our own findings it appears that the growth of a male or a female plant from seed, except for the predisposition in the gender chromosomes, also depends on various environmental factors. Not only the origination of entirely male or female plants is partly affected by these environmental factors, the number of male and female flowers on a hermaphrodite plant is affected as well. The environmental factors that influence the sex of the plant (or the flower in the case of hermaphrodites), are among other things: 

The quantity of nitrogen and potassium of the seedbed. 
Humidity and moistness of the seedbed. 
Level of temperatures. 
Colour of the light used. 
Length of daylight. 
Stress, any form of stress, makes that more male individuals will originate from seed. Even the taking of cuttings from female plants may produce male or hermaphrodite cuttings. 
To optimise the result, changes in one or more of the above-mentioned environmental factors for a certain period during growth, may be applied. During this time these environmental factors will deviate from the standard growing system for maximum harvest and quality, as described in nursery literature. The desired change(s) in the environmental factor(s) are started from the moment that the seedling has three pairs of real leaves (not counting the seed-lobes). This is the moment that male and/or female predisposition in florescence is being formed. After approximately two weeks the standard growing system can be reconverted to. 
Of the 5 above-mentioned environmental factors the first three are the most practical: 

1. Level of nitrogen and potassium of the seedbed: A heightening of the standard level of nitrogen makes for more female plants originating from the seeds. A lowering of the nitrogen level shows more male plants. A heightening of the level of potassium tends to show more male plants, while a lowering of the potassium level shows more female plants. A combination of a higher nitrogen level for the period of a week or two and a lowering of the potassium level is recommended. 
2. Humidity and moistness of the seedbed: a higher humidity makes for an increase in the number of female plants from seed, a lowering for an increase in male plants. The same is valid for the moistness of the seedbed. 
3. Level of temperatures: lower temperatures make for a larger number of female plants, higher temperatures for more male plants. 
4. Colour of light: more blue light makes for female plants from seed, more red light makes for more male plants. 
5. Hours of daylight: few hours of daylight (e.g. 14 hours) makes for more female individuals, a long day (e.g. 18 hours) makes for more male plants. * 


Now let me just make a few adjustments here to this. You can do whatever you want to your plants in seedling stage and early vegetative stage of growth and it will not effect your final male to female ratios. The time when things should be near perfect is in or around the 3rd to 4th week of vegetative growth. This is the CRITICAL TIME for getting those female ratios up and up. I realized this clearly when noticing how some plants hermed because of problems that occurred around this period of the plants development. If the problems occurred before this time - no herms. So for this reason I surmised that this is when the crucial gender selection is made by the plant. Now I believe that the genders are set in the seed however the environment has a massive impact on how this is expressed in the final phenotypic expression of the plants gender. There are probably many genes that govern this, however lets get into how to up these female ratios. 

At the 3rd to 4th week of vegetative growth make sure that your plants are free from stress. No pests attacks, no fungi attacks, no mold, no irregular photoperiod, not underwatered, not overwatered, not pruned or topped, a cannabis friendly soil mix, not recently transplanted, no small pots. If have these basic growing conditions under control then we can move onto the real forces of female production from standard seeds. 

N:K and nutrients. What this simply boils down to is that you have the right nutrients present in the right ratios. A nutrient formulation that has roughly equal parts N, P and K is great but if the P levels go up or the N levels go down you are starting to look at a flowering type food for cannabis. If you do this then your odds of producing mostly females is greatly decreased. Make sure that you get those N, P and K levels to almost run from higher to lower amounts from N to P and K. I have noticed that equal portions of N to P an K can help with the female ratios but the higher N is certainly more helpful. So around the 3rd of 4th week of growth make sure that the ratios are good and that P or K has not gone above the N and P or else more males will occur. Obviously this means to avoid overfeeding your plants around this time too. 

Never let your medium dry out completely around the 3rd to 4th week of vegetative growth. If you make sure to water occasionally, but not to overwater your plants, you will get those female ratios on the up and up. Overwatering or drying out of the medium will only produce more males. For consistent results in getting more females keeps those mediums moist. 

Humidity. Now this is the tricky one. High humidity levels only promote fungi and mold development and lowering humidity levels is the way to cure most of this rot but by keeping those humidity levels up in or around the 70 rH factor will help to produce more females. If you have a low humidity grow room then you should get to hold of a humidifier. Now high humidity levels like 70rH cause the medium to dry out a lot quicker so you got to keep this under control too. Keep those mediums moist and those rH levesl at 70. This will help to improve those female to male ratios. Again, getting them on the up and up. 

If you run the 24/0 photoperiod then do not allow those temps to go anywhere above 85 unless you have an equatorial strain. 75 is the best but going a little lower is not a problem for helping those female ratios. If you can get in at around 65 then those females are going to be popping up all over the place. The problem with this is that some growers like to use the 18/6 photoperiod and when the lights are off the temps drop from around 65 to 50 and even less. Try not to be below 55 because this has the adverse effect on the plants producing more males than females. Again between 65 and 75 is where you want to be during the 3rd to 4th week of vegetative growth, the preference being 70. 

Invest in a MH Light for vegetative growth. Dump the HPS bulb for flowering later. I have noticed that HPS lighting during vegetative growth simply sends those males to female ratios all over the place. With MH lamps the females are everywhere. Invest in some MH HID lights. It makes all the difference in getting those females to show more often. This is worth repeating! MH Bulbs produce more females under optimal conditions especially if they are present during the 3rd and 4th week of vegetative growth. Surprising enough you can start seedlings under HPS and it will not have an effect on those female ratios. Again the 3rd to 4th week of vegetative growth is what is important here. 

No stress during the 3rd to 4th week of vegetative growth. That is all there is to it. If you got your garden growing in optimal conditions without plant stress then the impressive 90% to 95% females start to emerge from standard seed packs. I find that topping is best done at the second to third week of vegetative growth but that this is a little stressful and can lead to those female ratios dropping again. Avoid topping or pruning if you are looking to up the female count. 

That is all I have to say for the moment. These little snippets of information in conjunction with what DP uncovered have helped my female ratios considerably. Hopefully you can see the same results too. Have fun getting those environments optimal for females!!!!!!!!

Source : Newf


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## buffdog (Aug 5, 2008)

so brv is same for hydro?


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## CaNNaBiZNeSS (Aug 5, 2008)

good input on an already amazing article im in 3rd week now tryna treat them like GODDESSES i got 9 plants outdoors on a short cycle


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## Silky Shagsalot (Aug 5, 2008)

bonz said:


> well i geusse i will eat my words on the fact that environment wont effect male female out come. haven`t tried this yet but i think it deserves a try at least.
> 
> 
> contrare pierre, environment indeed does effect sex early on. of course, there are different opinions, but a breeder i know says otherwise.


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## bonz (Aug 5, 2008)

ya i see alot of discussion on this. and i was a firm believer that it was genetics and environment couldn`t change it, well this is the evidence i needed to change my mind.


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## born2killspam (Aug 5, 2008)

I wouldn't be surprised if these findings are right, and wrong at the same time.. I too am a firm believer that gender is determined at the time of firtilization.. I wonder these methods are more successful on hermie prone strains.. If they are, then I would venture that these techniques ultimately control the expression of the hermaphrodite trait.. I would imagine that virtually all genetics have crossed with others carrying the hermie trait, because herming out is such a powerful survival strategy.. I don't know hermaphrodism originated, but my hypothesis is that if you could find genetics that had never crossed with a hermie, then these techniques wouldn't affect gender probabilities at all, just produce very healthy plants..


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## Inspectah (Oct 22, 2008)

great thread


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## shsironm4n (Nov 3, 2008)

i like what im hearing


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## thelastpirate (Nov 4, 2008)

I can see where one would think that a plants sex is genetically "graven in stone", but if it's all about genetics, and environment factors don't come into play, explain hermaphrodism.


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## ThE sAtIvA hIgH (Nov 4, 2008)

so why dont you get a 100% success rate ? if the enviroment was infact controlling the sex of the seed then you would get 100% females , you cant say the enviroment is having an effect on the sex whilst some seeds grown in the exact same way are turning out male , its a complete contradiction . unless you could then look at the seeds that wernt affected by the enviroment , and find out what is different with those seeds .


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## ThE sAtIvA hIgH (Nov 4, 2008)

quote Stress, any form of stress, makes that more male individuals will originate from seed. Even the taking of cuttings from female plants may produce male or hermaphrodite cuttings. quote 

how can taking a cutting from a female plant turn it into a male cutting ?


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## born2killspam (Nov 4, 2008)

It won't be male, but could end up XX pollen bearing.. Stress messes up internal systems, and often the result is intersex flowers..
As I've said, its my belief that environment can simply compell a plant to grow flowers that its genetics hadn't particularily intended to grow.. Just like humans, there is very little genetic difference between males and females.. Its testosterone that makes men phenotypically male.. Even if the genetics are there to create a male, if testosterone is impeded you'll get a little girly-man at best.. A hormone closely linked to sex expression in cannabis is ethylene.. All those feminizing techniques are designed to screw up ethylene pathways, and it can happen without even trying if the environment isn't up to par..


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## thelastpirate (Nov 4, 2008)

ThE sAtIvA hIgH said:


> quote Stress, any form of stress, makes that more male individuals will originate from seed. Even the taking of cuttings from female plants may produce male or hermaphrodite cuttings. quote
> 
> how can taking a cutting from a female plant turn it into a male cutting ?



I would say in much the same way that a female grown from seed can become an hermaphrodite. Stress.


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## bonz (Nov 4, 2008)

sorry guys i have done more readings and talked to a few people and this was alll bs.
this originaly only refered to their fem seeds and has been disproven since the articall came out.
good sales pr is all it ended up being.
see what happens when you dont research something before posting bull shit info.
just cause it is on the net dont make it true....this one got me....and many others to.


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## FRaNKLYuNAMeRICAN (Jan 25, 2009)

I want to know where the author gets his seeds. 90 to 95% female plants from standard seeds. That is incredibly impressive. I am in my first grow right now and have yet to get to the point to sexing my plants but I am assuming 65-45 female to male ratio at the best...


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## born2killspam (Jan 25, 2009)

I definately wouldn't want to breed with seeds that showed that ratio.. Environment during very early vegging has been linked with sex 'expression', but its also fairly well understood that plants genotypes follow the XX/XY configuration.. My hypothesis is that as stress can induce an XX to express male flowers, ideal conditions early on may be able to express female gender on an XY chromosomed plant..


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## Silky Shagsalot (Jan 25, 2009)

i read at overgrow (a long time ago) that if you put your seeds on 12/12 as soon as they sprout, and then switch back to your regular veg schedule once you get your first "true set" of leaves, that you'll get 80-90% female. i never tried it myself.


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## DaveTheNewbie (Jan 26, 2009)

Silky Shagsalot said:


> i read at overgrow (a long time ago) that if you put your seeds on 12/12 as soon as they sprout, and then switch back to your regular veg schedule once you get your first "true set" of leaves, that you'll get 80-90% female. i never tried it myself.


seems both 
1) too easy
2) more stress like (therefore more male like)

but damn if that worked it would be awesome.

if nobody else trys it im going to next seed batch i do


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## born2killspam (Jan 27, 2009)

But isn't it a fairly common problem for ppl at low lattitudes to end up with plants that want to flower at early spring?? Wouldn't we have stumbled across this fact serendipitously if it was true?


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## StealthyGardener (Jan 27, 2009)

Pretty complicated stuff. I've been experimenting with UV. This grow was the 1st to get very high amounts of UV right from the start of flowering. 80% females. I have my own breeding program and this is the 4th generation. 1st 3 gens were typical 50-60% female. Not sure if the UV is responsible - too early and need more testing. But this was an unexpected benefit. The UV definitely stressed the plants big time - so in this case stress = females.


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## Silky Shagsalot (Jan 27, 2009)

i think people worry too much about stress. you "really" need to screw up to stress your plant to the point of turning hermie. if you have a stable strain, chances are pretty good nothing will happen from things like trimming/lst etc. (of course, excluding femmed beans) you know, it's no cake walk out in the wild. outdoor plants probably encounter stressful situations repeatedly, every day.


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## tafbang (Dec 6, 2010)

ThE sAtIvA hIgH said:


> so why dont you get a 100% success rate ? if the enviroment was infact controlling the sex of the seed then you would get 100% females , you cant say the enviroment is having an effect on the sex whilst some seeds grown in the exact same way are turning out male , its a complete contradiction . unless you could then look at the seeds that wernt affected by the enviroment , and find out what is different with those seeds .



It's just like having human hermes or gay kids. sometimes the genetics just aren't alpha. You brought a good argument, though. Rep me I'm new. If they have rep. I'm 2weeks in on my 1st grow. wish me luck <3


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## wanabe (Dec 6, 2010)

dam this is very intersting thank you


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## TaoWolf (Dec 6, 2010)

tafbang said:


> It's just like having human hermes or gay kids. sometimes the genetics just aren't alpha. You brought a good argument, though. Rep me I'm new. If they have rep. I'm 2weeks in on my 1st grow. wish me luck <3





tafbang said:


> It's just like having human hermes or gay kids. sometimes the genetics just aren't alpha. You brought a good argument, though. Rep me I'm new. If they have rep. I'm 2weeks in on my 1st grow. wish me luck <3


Human hermaphrodites are still genetically male or female and won't have two functioning sex organs - it's one or the other or neither as far as functionality goes (i.e. hermaphroditism is a 'condition' and not a 'gender'). Homosexuals prefer the same gender as that of their own but they are still male or female. In all cases actual gender is controlled by the presence or absence of Y sex chromosomes at the genetic level and Y chromosomes can only come from a male parent. The same deal holds for dioecious plants like cannabis. X and Y chromosomes have been marked in lab settings specifically on cannabis plants.

Hermaphroditism in female cannabis occurs naturally through autosomal genetic information that can be impacted by external factors and can result in both male and female sex organs that are viable. But again, hermaphroditism is a condition and not a gender nor a 'gender change'. Female hermaphroditic cannabis plants are still 'female' and as such can only produce and pass on XX sex chromosomes. 

So while it may be true to say environment can impact hermaphroditism, it is genetically impossible to impact actual gender. Actual gender and the ability to produce offspring of either gender is genetically predetermined at the time seeds are produced by the presence or absence of Y sex chromosomes donated from a male plant - if there. If no male was involved, there are no Y sex chromosomes in the seeds and so the seeds will invariably only have XX sex chromosomes (feminized).


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## |3laze (Dec 6, 2010)

Good info TaoWolf, it always amazes me how many people still believe they myth that environment influences the sex of seedlings.


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## tafbang (Dec 6, 2010)

they are born in with the possibility to suffer from those conditions?


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## TaoWolf (Dec 6, 2010)

Yes:

Chromosomes determine gender. An X chromosome and a Y chromosome equals a male (it's actually the Y chromosome that has the genetic information that makes an organism 'male'). Two X chromosomes equals a female (no Y chromosome... no male). Chromosomes are set at creation (seed formation) and *are not* impacted by environment later.

Autosomes determine the expression of hermaphroditism and are also inherited genetic information like chromosomes. However, autosomes contain genetic information that can be switched on or off as a plant grows. Often autosomes instruct a plant on how to grow and live in response to variables that will be in a changing environment. 

When talking about cannabis, hermaphroditism isn't really a disease or something they suffer from, it's just an autosomal trait that's successful in survival. And the expression of traits can be minimized (or encouraged) through generations of selective breeding...

Even though it's often claimed that breeders producing feminized seeds are responsible whenever a plant shows a hermaphroditic trait or tendency, the opposite is actual true. Breeders of commercial strains have actually suppressed the common expression of hermaphroditism as a trait in cannabis grown for medical/drug purposes through selective breeding. Commercial hemp and non-cultivated cannabis plants naturally exhibit hermaphroditism more often than what we see with purchased seeds.


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