# Can the Environment influence the Gender?



## ISK (Oct 4, 2014)

Some believe the gender of marijuana seeds are predetermined, while others believe that the correct environment can highly influence the outcome (+90%) of your plant to become female.

I find this is an interesting subject, as there is a bit of truth to both sides of the fence. 
Most would agree that feminized seeds have a predetermined gender (99.999%)..... and many believe that improper environment conditions such as light leaks, over-heat/nutes/watering, altering light schedule, etc, can trigger a female to turn hermaphrodite.

I am considering conducting a side by side experiment of this subject by creating one room with what would be considered ideal female conditions, and another room with less favorable conditions that could influence the gender to become male.

For those that believe the environment is a factor; I'm asking for feedback if the listed are the ideal conditions to influence a female gender, and are there other conditions to consider.
• Temp = 77F
• RH = 70%
• Lights = Blue (example 6500K or MH)
• Light Schedule = 16/8

The "male environment room" would have:
• Temp = 85F
• RH = 30%
• Lights = Red (example 2700K or HPS)
• Light Schedule = 20/4

For those that believe gender is predetermined, your thoughts on the attached chart that implies one can visually determine the gender of the seed

cheers


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## bf80255 (Oct 4, 2014)

That chart is phony
And gender can be influenced in cannabis as in more nitrogen in the medium, cooler temps, differwnt light cycles all of that can skew the ratio of males to females unless your using femmed seeds then its usually mostly female and the odd hermi


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## neonknight420 (Oct 4, 2014)

In all my years i have never seen or heard of such chart. I only know of above ^^^^^^ such findings, nitrogen, more blue light, cooler temps etc. produce more females.


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## Sativied (Oct 4, 2014)

That stupid image is reposted every few months, it's bullshit.

You can influence the "sexual expression" of cannabis plants, its "reproductive commitment is flexible up to the 4th or 5th node. You can't change the genotype (XX and XY) but like many genotypes the environment influences how it's expressed, as in the phenotype. For example, you can have a male by genes that expresses as a female phenotype. A grower won't notice or even have to know the difference as long as it expresses fully as male/female.

_-----------------------------_
_Cannabis sativa_ L. is a dioecious species with sexual dimorphism* occurring in a late stage of plant development. Sex is determined by heteromorphic chromosomes (X and Y): male is the heterogametic sex (XY) and female is the homogametic one (XX). The sexual phenotype of _Cannabis_ often shows some flexibility leading to the differentiation of hermaphrodite flowers or bisexual inflorescences (monoecious phenotype). Sex is considered an important trait for hemp genetic improvement; therefore, the study of the mechanism of sexual differentiation is of paramount interest in hemp research. A morphological and molecular study of _Cannabis sativa_ sexual differentiation has been carried out in the Italian dioecious cultivar Fibranova.

Microscopic analysis of male and female apices revealed that their reproductive commitment may occur _as soon as_ the leaves of the fourth node emerge; the genetic expression of male and female apices at this stage has been compared by cDNA-AFLP. A rapid method for the early sex discrimination has been developed, based on the PCR amplification of a male-specific SCAR marker directly from a tissue fragment.

Five of the several cDNA-AFLP polymorphic fragments identified have been confirmed to be differentially expressed in male and female apices at the fourth node. Cloning and sequencing revealed that they belong to nine different mRNAs that were all induced in the female apices at this stage. Four out of them showed a high degree of similarity with known sequences: a putative permease, a SMT3-like protein, a putative kinesin and a RAC-GTP binding protein.

http://link.springer.com/article/10.1007/s10681-004-4758-7 
_-----------------------------_

*Sexual dimorphism is a phenotypic difference between males and females...


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## ISK (Oct 4, 2014)

@Sativied

If I may paraphrase you in a rudimentary summary for clarity; every seed does have a predetermined gender but the environment still can influence the final outcome of the gender?

@bf80255 @neonknight420

I would like to establish just which environment factors can influence a female gender

you both have stated the higher levels of nitrogen, as well as blue light and cooler temp....is the higher RH a factor, and the light cycle?


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## Sativied (Oct 4, 2014)

ISK said:


> @Sativied
> If I may paraphrase you in a rudimentary summary for clarity; every seed does have a predetermined gender but the environment still can influence the final outcome of the gender?


Exactly. It's that predetermination (based on the parent sex genes) is what allows for the creation of feminized seeds (XX crossed with XX is always XX) but at the same time they are also called feminized instead of female seeds because it's not a guarantee they will grow out in females. 

Which factor influences it which way I don't know. I've read several claims but never seen anyone test that properly. Your question was if the environment can influence the gender, to which the answer is yes. If you were to ask me if a grower should try and influence the environment to influence the gender I'd have to say no. It's hard to test because a 50/50 ratio on a 10 pack can lead to anyway from zero to 10 females simply based on (bad) luck. With 10000 seeds, there are roughly 5000 female, but even with 100 seeds you can mess with nutes, light or whatever, it if you get 70 females instead of 50, how can you tell your methods worked instead of it just being the luck of the draw. And what works for some strains, may not work for others.


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## bf80255 (Oct 5, 2014)

If genotypically its a male and you swing it female to me those are intersex traits being expressed aka a form of hermaphroditism and should be cool for bud but please dont use it to breed ir make seeds

I force out my hermis with pH swings light cyvle disruption and shock i dont have any experience using rH or different light spectrums so i cant say. I forget who but a well known breeder has an article on finding "true females" that has a bunch of ways to tuen boys girly using the methods stated in this thread. Just google it


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## neonknight420 (Oct 5, 2014)

RH is a factor high humidity increases females. Also fewer hours daylight increase females. More red light increases males. but as far as the shape of the hole at the bottom of a seed is just stupid.


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## BWG707 (Oct 5, 2014)

Back in the '70's it was rumored that crowding plants produced more males.


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## neonknight420 (Oct 5, 2014)

BWG707 said:


> Back in the '70's it was rumored that crowding plants produced more males.


I also used to here that, I would have to say their must be some truth to that. It makes perfect sense that crowding would increase males.


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## ISK (Oct 5, 2014)

neonknight420 said:


> RH is a factor high humidity increases females. Also fewer hours daylight increase females. More red light increases males. but as far as the shape of the hole at the bottom of a seed is just stupid.


Okay,so fundamentally you are confirming the conditions I posted in the OP are correct?.....plus higher nitrogen levels as mentioned by yourself and bf.
would you agree with the specific numbers I listed?....cool temps (~77F), high RH (~70%), hours ( 16 - 8 )


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## neonknight420 (Oct 5, 2014)

Yes, temps look good RH looks good and 16/8 light regimen is the preferred cycle. All of this is supposed to be started around the 3rd node not including the cotyledon leaves.


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## ISK (Oct 5, 2014)

the feedback received on the chart so far has been; "chart is phony", "stupid image" and "just stupid" , so can I concluded that many doubt its validity

My thoughts/experience: 

Last Christmas while in Mexico, I got a 1/4 ounce of low grade commercial pot that was loaded in seeds, so I brought home 92 seeds . 

I have noticed with these seeds, that some do visually have the characteristics shown in the chart depicting male or female.

Not saying that this chart is correct, but just saying some seeds do have that distinct volcano shape while others have sharper point more conducive to what is indicated as male.

This spring, my x-girlfriend insisted that I owed her 3 seedlings that I had promised her last summer when we were still together. 

So I offered her auto-fem's for my cost price, or these Mexican seeds for free....she choose the cheap option. 

I selected the three most male looking seeds as per the chart, and brought them to her as seedlings. 

All 3 grew into males...bad luck, coincidence, sheer fluke, twist of fate, karma or maybe....?


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## bf80255 (Oct 6, 2014)

BWG707 said:


> Back in the '70's it was rumored that crowding plants produced more males.


Pretty sure that crowding just increases stress on individual plants causing a high of occurrence of intersex traits (hermis) that were mistaken for males especially back in the 70s with all those landrace sativas grown outdoors, talk about hermi central!
The breeders collective genetics gone madd claim to have the capability of tellingmales from female seeds via high powered microscope, ateast thats what they ssay


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## BWG707 (Oct 6, 2014)

bf80255 said:


> Pretty sure that crowding just increases stress on individual plants causing a high of occurrence of intersex traits (hermis) that were mistaken for males especially back in the 70s with all those landrace sativas grown outdoors, talk about hermi central!
> The breeders collective genetics gone madd claim to have the capability of tellingmales from female seeds via high powered microscope, ateast thats what they ssay


That makes a lot of sense. I remember seeing cornfields crowded with cannabis patches. Lots of males and pretty bad tasting buds, they seemed to take on some of the corn taste.


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## bf80255 (Oct 6, 2014)

BWG707 said:


> That makes a lot of sense. I remember seeing cornfields crowded with cannabis patches. Lots of males and pretty bad tasting buds, they seemed to take on some of the corn taste.


Hahaha corn tasting weed!?! Sounds.... not terrible... id try it


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## harris hawk (Oct 7, 2014)

Generally the darker colored seeds have better germination rates


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## neonknight420 (Oct 7, 2014)

ISK said:


> the feedback received on the chart so far has been; "chart is phony", "stupid image" and "just stupid" , so can I concluded that many doubt its validity
> 
> My thoughts/experience:
> 
> ...


Well take your remaining mexican seeds and start doing some test. Let everyone here Know your findings, it really would be pretty cool if it were true. I still have my doubts.


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## ISK (Oct 7, 2014)

neonknight420 said:


> Well take your remaining mexican seeds and start doing some test. Let everyone here Know your findings, it really would be pretty cool if it were true. I still have my doubts.


Thanks...I am going to start the experiment in a few weeks...I will use "male looking" seeds in the female environmentally friendly room.... and "female looking" seeds in the male environment room...kind of a double down`


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## Stompromper (Oct 8, 2014)

I know a guy that insists cooler temps during germ make females and warmer temps make males. I just plant and kill the males lol.


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## FrozenChozen (Oct 9, 2014)

Stompromper said:


> I know a guy that insists cooler temps during germ make females and warmer temps make males. I just plant and kill the males lol.


what about all the people who germinate on heating mats? they don't seem to have "higher chances" of being male....
I say 75% genetic and 25% environmental + or - 5%


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## neonknight420 (Oct 9, 2014)

FrozenChozen said:


> what about all the people who germinate on heating mats? they don't seem to have "higher chances" of being male....
> I say 75% genetic and 25% environmental + or - 5%


Heating mats keep the roots warm not the atmosphere.


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## FrozenChozen (Oct 9, 2014)

neonknight420 said:


> Heating mats keep the roots warm not the atmosphere.


which *DIRECTLY* influences the temperature of the plant.....


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## ISK (Oct 26, 2014)

I started to germinate 12 seeds today, 6 male and 6 female looking seeds as per the chart...the top 5 from each gender will continue.

The top 10 will be grown in a hempy style (Drain to Waste) perlite/vermiculite c/w a soil cap & core, using a 16 ounce Dixie cup.

The female friendly room (ideal environment conditions for a female) ...the 5 male looking seeds will go into this room

approx 77 F and 70% RH.
16/8 light cycle
6500K CFL bulbs (blue light)
General Hydroponics MaxiGro (10-5-14)
The male friendly room (ideal environment conditions for a male) ...the 5 female looking seeds will go into this room

approx 85 F and 30% RH.
20/4 light cycle
2700K CFL bulbs (red light)
General Hydroponics MaxiBloom (5-15-14)
Note: I only plan to grow these until the gender of each is determined.

cheers


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## Cold$moke (Oct 28, 2014)

Very interesting .


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## ISK (Nov 2, 2014)

Germination has not been going well...only have 3 of each sprouted so far...the other 6 seeds are taking their sweet time. 

For now I have them in a common room but will soon separate to their appropriate rooms....I have the males on the left side under two 6500K and one 5K...the right side are the females under two 2700 K and one 5K 

 

The Female seeds

 

The Males


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## Cold$moke (Nov 2, 2014)

Ouch on the germ rate but still look forwrd to the results


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## ISK (Nov 3, 2014)

Cold$moke said:


> Ouch on the germ rate but still look forwrd to the results


I'm not happy with the germination rate as I really wanted 10 plants, 5 of each... but I'll continue with the six..... they seem to be progressing well


and the females


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## ISK (Nov 4, 2014)

Started the second room today and have separated the two genders...working on the temp/RH, not quite right yet but getting close

The new female friendly room
 

 
getting close to the ideal RH..... but temps are a bit low.....more lights should help
 

The male friendly room... a bit cool but RH is low......... 77.4 F / 34% RH
 

The gals are looking good


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## ISK (Nov 5, 2014)

the female friendly room is about 65% RH but still cool at 72 F
 

The male friendly room is running over 40% RH...and a bit cool


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## ISK (Nov 6, 2014)

girl's room is cool at about 72 F and 60-65% RH
 

75-76 F and around 40% RH for the male room


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## ISK (Nov 7, 2014)

the RH is looking good and temp are still low but not bad for the girl's room



the temps are lower than I want...but the RH is decent for the male room


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## ISK (Nov 8, 2014)

about a week old, a few pics of side by side

    

Temp/RH in girl's room
 

Temp/RH in boy's room


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## ISK (Nov 9, 2014)

I have increased each room to six-23 watt CFL's 

Girl's room...four-23 Watt 6500K and two-5000K CFL's 
 

the boy's room....four-2700 watt and two 5000k CFL's


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## ISK (Nov 11, 2014)

pic's from yesterday....I'm getting the temp/RH dialed in now

Female friendly room
 

male friendly room


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## ISK (Nov 14, 2014)

The girl's room....temp is a touch low but RH is great


The male room has the +80 temps and the RH is so low the meter can't read it (under 20%)



It does appear the plants in the female friendly room are progressing faster than the ones in the male friendly room....but this experiment is all about influencing gender not performance


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## Blitzedgrowkid08 (Nov 14, 2014)

Just caught this! Very curious to see the results


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## ISK (Nov 14, 2014)

Blitzedgrowkid08 said:


> Just caught this! Very curious to see the results


thanks Blitzed...no idea how it will end up, but having fun with the experiment ....cheers


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## ISK (Nov 15, 2014)

Added an extra pair of 23 watts lights to each room (8 per room total)...would like to flip to flower mode in about a week

the Girl's room (6 x 6500K and 2 x 5000K CFL's) temps around 70-74F.... 65-70% RH
 

the Boy's room (6 x 2700K and 2 x 5000K CFL's) temps around 79-83F and 20-30% RH
 

some side by side pics....the plants in the female friendly room are a fair bit bigger than the male friendly room
left side (male seeds/female room)....right side (female seeds/male room)
 

left side (male seeds/female room)
 

right side (female seeds/male room)


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## ISK (Nov 16, 2014)

Girl's room 
 

Boy's room


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## SeedHo (Nov 16, 2014)

i`m going to hang around to see the results.


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## ISK (Nov 17, 2014)

the female friendly environment room


the male friendly environment room


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## SeedHo (Nov 17, 2014)

isk are these all the same strain or is that a lotto too? they look very similar, just wanted to be clear on that.


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## ISK (Nov 17, 2014)

SeedHo said:


> isk are these all the same strain or is that a lotto too? they look very similar, just wanted to be clear on that.


Yes, all the same strain....from a 1/4 ounce I purchased in Mexico


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## LordDiesel (Nov 17, 2014)

been trolling in the background since the start, super intrigued to see whats what. looking great man good looks.


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## SeedHo (Nov 18, 2014)

ISK said:


> Yes, all the same strain....from a 1/4 ounce I purchased in Mexico


cool that is what i thought but no since in assuming.
when it comes to the flip, how do you plan to do it. are you just changing the light cycle or are you adding a period of darkness first?


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## burgertime2010 (Nov 18, 2014)

what i would do is take clones guaranteed to be females and see if you can get them to herm. Seeds are not going to give you a certain answer.


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## ISK (Nov 18, 2014)

LordDiesel said:


> been trolling in the background since the start, super intrigued to see whats what. looking great man good looks.


thanks for the feedback LordDiesel


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## ISK (Nov 18, 2014)

SeedHo said:


> cool that is what i thought but no since in assuming.
> when it comes to the flip, how do you plan to do it. are you just changing the light cycle or are you adding a period of darkness first?


I typically would just flip to 12/12 but I have grown this strain before and it was tough to trip...... I had to go 11/13 to get them to flower...

.so I will likely do the same this time but I had thought about a day of darkness first


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## ISK (Nov 18, 2014)

burgertime2010 said:


> what i would do is take clones guaranteed to be females and see if you can get them to herm. Seeds are not going to give you a certain answer.


this experiment is also about if one can determine the gender of a seed by its looks


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## Hot Diggity Sog (Nov 18, 2014)

Cool experiment but I think the sample size is simply way too small to provide useful data. Maybe 100 in each group...but 3 is not enough.


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## SeedHo (Nov 18, 2014)

good deal......its amazing to see what a difference the environment has played so far, i like the plant growth in the male room. i know its not part of the experiment just a observation.


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## ISK (Nov 18, 2014)

Hot Diggity Sog said:


> Cool experiment but I think the sample size is simply way too small to provide useful data. Maybe 100 in each group...but 3 is not enough.


agree, the small sample size will not give a definitive conclusion but rather just merely an indication.


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## ISK (Nov 18, 2014)

SeedHo said:


> good deal......its amazing to see what a difference the environment has played so far, i like the plant growth in the male room. i know its not part of the experiment just a observation.


Yes, the different environments are clearly impacting the plants growth pattern


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## ISK (Nov 18, 2014)

the boys are doing good in the female friendly environment room
 

The girls in the male friendly environment room


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## rohis (Nov 19, 2014)

I immagine in the next couple years, this thread will have a definitive answer as our hobby grows and more studies are done.The hormones of the plant still have a lot to teach us.

My take on it is the same as people. When you give a man female hormones, he'll grow tits. When you give a woman male hormones, she turns into my mother-in-law. Too many masculine hormones, and anything can happen.

As the grower, the environment you create will most certainly affect the plants hormones. We know slacking here causes hermaphrodites. Are certain strains or genetics more susceptible to this? I would imagine yes... Do the conditions we provide early in life determine the sex though? I don't think me or science have an answer for that yet.

BUT

as someone who has kept and bred many species of gecko, I can tell you 100% that the temperature the eggs are incubated at WILL determine the sex of many many many lizards.

Take leopard geckos for example:
Incubate their eggs between 86-90 degrees, they will be predominantly male.
Incubate them at 80-84, and they will be predominantly female.
Incubate them right at 85? You get a den full of geckos that are confused about their gender and frequently try to mate with their same sex.

I know Gecko's aren't weed, but food for thought.

Personally, I think it's highly possible to produce some kind of hormone or product that will drastically increase your female to male ratio, but I don't 'know' that.

ISK, I LOVE your experiment. But I HATE that you're using tin foil


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## ISK (Nov 19, 2014)

rohis said:


> ISK, I LOVE your experiment. But I HATE that you're using tin foil


Thanks rohis, I appreciate your comments

As for the tin foil...IMHO when using 23 watt CFL's, tin foil cannot cause any hot spots or damage to the plant, as the bulb has to touch the leaf for hours to damage it


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## rohis (Nov 19, 2014)

Very good point!


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## Cold$moke (Nov 19, 2014)

I thought of the frogs that can change sex when I first read about these type of studies.

but was I thinking of jurasic park lmao. Jk


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## ISK (Nov 20, 2014)

the boys in the female friendly environment room
 

the girls in the male friendly environment room


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## bryleetch (Nov 20, 2014)

Very interesting thing you have going here. Definitely a start in the right direction to get some answers but I wish I saw this sooner so that I could've recommended something to better improve the experiment. A good idea would have been to put some female looking seeds in the pro-female conditions and the male looking seeds in the pro-female along with the vice versa like you currently have. This would give your results something to be compared to rather than just standing alone. Instead of "female seeds in male environment are X% male" you could also deduce "female seeds in male environment are X% but X% in a female environment". It just makes it easier to get a better conclusion of what's happening, especially on such a small scale it helps even more. Regardless, I still like what you have going here and interested to see what'll happen. A lot of people on her say they're going to experiment stuff but never follow through, glad to see someone is actually keeping their word. Good luck rest of the way!


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## ULEN (Nov 20, 2014)

If PCB's have the same effects on plants, would it mean a higher chance of herm or female ratio? Nothing against nobody but that's the end of the line when speaking about keeping your genes a float of the ocean.


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## bryleetch (Nov 20, 2014)

ULEN said:


> If PCB's have the same effects on plants, would it mean a higher chance of herm or female ratio? Nothing against nobody but that's the end of the line when speaking about keeping your genes a float of the ocean.


I don't think(not 100% sure) they do have the same affect in plants due to plants not having an endocrine system with glands like mammals and other animals do. Some plants can actually absorb PCB's and render it, it's called bioremediation. Not sure if cannabis is capable of that but exposure to this would most likely just stress it to the point of going herm or die unless it is capable of bioremediation. In that case, we should propose growing cannabis to the EPA in order to absorb pollutants!


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## ISK (Nov 20, 2014)

bryleetch said:


> Very interesting thing you have going here. Definitely a start in the right direction to get some answers but I wish I saw this sooner so that I could've recommended something to better improve the experiment. A good idea would have been to put some female looking seeds in the pro-female conditions and the male looking seeds in the pro-female along with the vice versa like you currently have. This would give your results something to be compared to rather than just standing alone. Instead of "female seeds in male environment are X% male" you could also deduce "female seeds in male environment are X% but X% in a female environment". It just makes it easier to get a better conclusion of what's happening, especially on such a small scale it helps even more. Regardless, I still like what you have going here and interested to see what'll happen. A lot of people on her say they're going to experiment stuff but never follow through, glad to see someone is actually keeping their word. Good luck rest of the way!


that's not a bad idea... maybe next time

there will be three possible outcomes to each room...3 males, or 3 females, or a 2/1 split. 

IMO, the experiment will be completely inconclusive if I get a 2/1 split in either room.....so it has to be 3/0 to even be considered an indication or likelihood


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## bryleetch (Nov 20, 2014)

ISK said:


> that's not a bad idea... maybe next time
> 
> there will be three possible outcomes to each room...3 males, or 3 females, or a 2/1 split.
> 
> IMO, the experiment will be completely inconclusive if I get a 2/1 split in either room.....so it has to be 3/0 to even be considered an indication or likelihood


Yea that's the downside of such a small sample but this is a good start to finding answers


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## ISK (Nov 20, 2014)

bryleetch said:


> Yea that's the downside of such a small sample but this is a good start to finding answers


it's all about my addiction to growing,,,, this experiment is just to fill in the void until Christmas.....I'll be leaving town, so I'll start my real grow when I return in 2015


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## ISK (Nov 22, 2014)

the males in the female friendly environment

 

the females in the male friendly environment
 

The side by side line-up (males left, females right)
 

the males
 

the females


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## ISK (Nov 24, 2014)

This weekend I switched the lights to 11/13 (on/off), so should be seeing signs of gender in the next few days

The males in the female environment
 

The females in the male environment


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## ISK (Nov 28, 2014)

It has been 6 days since I reduced the hours to 11/13 and still no signs of gender....hopefully in a few more days

the males in the female environment




the females in the male environment


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## ISK (Dec 1, 2014)

9 days of 11/13 and still no signs of gender....last time I grew this strain it went 2 weeks without tripping, so I reduced to 11/13 and it tripped in 4 days.... this time I started with 11/13 but may still be a longer wait.

cooler nights now, as the both rooms can drop to 55-60 F at night

I revamped both rooms to give more space...also added jars to stabilize the Dixie cups as they were getting very unstable when dry/light

the males in the female room
 

the females in the male room


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## ISK (Dec 5, 2014)

They are starting to show gender, still have 2 that I'm not a 100% sure yet, so I'll hold off on the results/pic's until such time

I am surprized that with 1500+ views that nobody has made a prediction....any takers?


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## bryleetch (Dec 5, 2014)

My Prediction: 2:1 split in each environment, leaning towards 2 females in both environments and a male in each. Completely just guessing here lol

I hope I'm wrong though it would be way more interesting to see at least one of the environments have all fem or all male. Even if it doesn't turn out ideally, at least this gives a nice side by side comparison of how differently plants grow in these two environments. 
Can't wait for the outcome!


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## T.H.Cammo (Dec 6, 2014)

I'm predicting 3 males in the female room and one male in the male room - based solely on height / bushiness!

I'll bet I have "skipped over" (not looked in) this thread a hundred times. Because, i guess, like some people, I feel I already know eveything (LOL). But, ISK, "_*You Da Man!*_"! I don't think I have ever seen an experiment run here at RIU with such downright enthusiasm and "follow through" - not to mention taking all the "suggestions" into consideration. The sample size might be small; but like you said, "There is always next time". THIS IS THE BEST EXPERIMENT I HAVE SEEN CONDUCTED HERE! Top marks for thoroughness and regular updates.

Anyway; back to the original idea behind the experiment. Let me make a brief statement about what my old freind / mentor once told me. Predetermined is such a "harsh" word, it's like "predestined", very matter of fact - "That is the way it will be". Seeds are more like "predisposed" - they are more likely to emerge either as a male or female plant - but that can be changed / affected by a number of factors. Predisposed is just a little more "iffy" than predetermined. That idea may not be very scientific but it is a hell of a lot easier to understand!


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## Cannasutraorganics (Dec 7, 2014)

There was a study done. If you plant 100 of good seeds and all germinate. If you have over 60 females that's a female dominate strain and planting those seeds in soil that previously grew a male plant, makes around 90% females. In male dominate strains the results were about 50% increase in females with male soil.
They hypothesized that having the male hormons left in the soil made them express the female because a male should have been present. But when things changed they hermied more often. So I go with let them grow and thin the males... Less chance of getting screwed in the end with hermies.


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## ISK (Dec 7, 2014)

T.H.Cammo said:


> I'm predicting 3 males in the female room and one male in the male room - based solely on height / bushiness!


Thanks T.H.C for your compliments, I appreciate your comments/feedback..... next time I would hope to have a larger sample and better control variables

Your prediction is very logical based on past experiences, but with this strain old-school logic doesn't necessarily apply. 
I grew five of these Mexican seeds last winter and everyone thought at least 4 of 5 would be males as they were tall and thin, but turned out 4 of 5 were females.
Three of the female were about 5 foot tall, the runt was over 3 feet...I believe they are mostly sativa
 

@bryleetch ...your prediction could turn out correct but I'm still waiting on one plant to reveal its gender....go figure why one would be so far behind the others

One room has 2 females and 1 male, and the other room has 2 females and 1 TBD....I'm guessing it will become female as males typically mature first, but not always

Side by side pic from yesterday, from left to right M1, M2, M3, F1, F2, F3.......which one would you guess to be the male? 

I'll post up full details on the final outcome once the last plant shows its gender


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## bradburry (Dec 8, 2014)

ISK said:


> that's not a bad idea... maybe next time
> 
> there will be three possible outcomes to each room...3 males, or 3 females, or a 2/1 split.
> 
> IMO, the experiment will be completely inconclusive if I get a 2/1 split in either room.....so it has to be 3/0 to even be considered an indication or likelihood


your not trying it with enough seeds.....all your readings 2/1 3/0 etc can all happen through chance there's not enough seeds to determine a true reading imo ..


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## keysareme (Dec 8, 2014)

m3 for male.


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## bradburry (Dec 8, 2014)

You cant rely on so few seeds for an accurate result


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## ISK (Dec 8, 2014)

The last plant showed gender yesterday, waited until this morning to be 100% sure.

Male looking seeds in the female environment friendly room:
72 to 75 F, 60-65% RH, blue lights (6500K), 16/8 light cycle, GH Maxi-Gro (10-5-14)...which was grown in a bathroom with good ventilation and air circulation
*2 females and 1 male* (the male was M1)

Female looking seeds in the male environment friendly room
78 to 84 F, 20-30% RH, red lights (2700K), 20/4 light cycle, GH Maxi-Bloom (5-15-14)...which was grown in a closet with no ventilation and poor air circulation, as I needed to keep the door close to retain heat
*3 females
*
Conclusion: hard to say with such a small number, but it is interesting that the room with such harsh environmental conditions could produce 3 females and the room with near perfect conditions does not.

So personally I believe the chart has merit but I also believe the environment has a huge factor in the plant's health and growth patterns....and also could influence the outcome of the gender

cheers
Indoor Sun King


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## bradburry (Dec 8, 2014)

It would be more solid if you used more seeds ...........im sure if there was a way to determine the sex of a seed it would have been found by now and we wouldn't have to go to such extreme methods like silver spray to get the seed we all so dearly seek........the female 




but nice try......remember me when your a millionaire lol


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## ISK (Dec 8, 2014)

Some final pic's of the plants:

M1 (the male) - voted off the island 
 

M2 - the best of the bunch 
 

M3 - this was the weakest seedling of them all but came on strong
 

F1 - she got fairly tall but was not as healthy as the ones from the female friendly room
 

F2 - this was the one we were waiting on to show gender
 

F3 - the runt of the litter
 

group pic of the females


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## ISK (Dec 10, 2014)

I was going to kill all these plants as I'm leaving town for the holidays, but I thought I would keep one alive for now

M2, the healthiest of the pack was transplanted into a 11 litre bucket.....I have started a new journal, as this experiment is complete
https://www.rollitup.org/t/hempy-from-dixie-cup-to-bucket.853672/

 

The roots from the terminated plants
 

M2, transplanted to a 11 litre bucket


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## waterdawg (Dec 12, 2014)

bradburry said:


> It would be more solid if you used more seeds ...........im sure if there was a way to determine the sex of a seed it would have been found by now and we wouldn't have to go to such extreme methods like silver spray to get the seed we all so dearly seek........the female
> 
> 
> 
> ...


So he needs more seeds right lol. Dont think this was anything more than for ops own curiosity not a definitive scientific experiment. Its kind of like a lets see what happens thing. I think thats kind of obvious lol.


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## madkw (Dec 13, 2014)

good day to all ,,
how can you tell if the plant is male or female !! 
also how long it take from day one tell harvest ? or what the faster way to do it 
is the strong stuff take longer to grow ??


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## qwizoking (Dec 13, 2014)

Soooo what are your findings?


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## purplehays1 (Dec 13, 2014)

george cervantes claims u can. He claims blue light, low temps and high humidity produces more female plants. I personally dont think this is true and find that as long as u dont stress the young plants in weed 3-6 then they are genearlly about 50% female, higher male rates are possible if you stress the plants or with certain genetics. So yes environment can effect the m:f ratio, but im,o its more to do with extremes stressing the plant.


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## qwizoking (Dec 13, 2014)

First and maybe only time I agree with Cervantes.


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## purplehays1 (Dec 13, 2014)

ya i still try to give my plants blue light, low temps and high humidity when they r from regular seeds, but i dont seem to notice a difference


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## qwizoking (Dec 13, 2014)

I notice a huge difference. It used to be seemingly random in my grows most of the time being mostly female. Temps were the main factor for me, I could count on 80% female just by having temps in the high 60's after germ and through sexing, while attempting to still optimize conditions. After adjusting humidity and nutrient ratios I easily got it to ~90..


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## GroErr (Dec 13, 2014)

Interesting experiment but not enough data for any sort of conclusion. IDK what I've been doing lately other than maintaining an 80/60 environment through seedlings and veg. In the last couple of months, I haven't been able to get a male even though I've wanted one. 80F/60RH has produced 8 fems from 8 reg seeds. 4x were DIY seeds, I know they're regs, the other 4 were reg Harlequin seeds, you never know though with commercial regs, could be called regs because of germination producing the odd male...


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## THE KONASSURE (Dec 13, 2014)

if you want males then run high temps with low humidity, and give more then 16 hours light and feed low N and higher pk and let them get dry before watering

Also if you use substraint from a female plant to germinate a seed it can be more likely to be male as there will be female plant hormones in the substrate so the plant will be slightly influenced to grow male


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## qwizoking (Dec 13, 2014)

Only thing I disagree with is the soil. Not saying it isn't a factor as I don't have perfect rates. But overall I avg 96%. And that's over hundreds of plants since my trials began last sept...but I also only use hps and many have said light color is a factor. I lean more to saturation levels over color and length

Ive been using the same soil for years composting the female plants back in as well. That rootball is amazing and supposedly can feed microbes up to 2 years.I doubt its that long but I do know phenols etc remain a good while


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## qwizoking (Dec 13, 2014)

Anyway sorry... Back to the thread...
What are your results so far good sir?


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## THE KONASSURE (Dec 13, 2014)

if you veg under hps 

the extra heat from all that red band can make more males come up as they think it`s later in the "season" then it is and that there will be tons of females for their balls 

If you were to switch to a 5000k or bluer bulb even if just for 2 week or so, you`d cut down males a lot and you`d get more nodes and bushing 

even running 12/12 from seed with 2000k or 3000k you still risk more males due to the extra heat and the extra stimulation of flowering hormones due to the balance of light 

if you have a dimmable hps ballast you could always turn it down and put a cool blue light of some kind in there too to balance things out ?


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## ISK (Dec 13, 2014)

qwizoking said:


> Anyway sorry... Back to the thread...
> What are your results so far good sir?


well as I mentioned, I find it interesting that the plants in the male friendly environment all became females, and those in the females friendly room only produced 2 of 3 females.

IMHO, I know my sample size was very small and no clear conclusions can be made, but I believe all seeds have a pre-determined gender but can be influenced by the environment

It appears the seeds depicting female characteristics still turned out female even when breaking every known rule, but yet the seeds depicting male characteristics can be influenced

at the end of it all, I can say for sure is that the female friendly room produced bigger healthier plants


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## Grojak (Dec 13, 2014)

germinating tems mater… colder temps have proven to make more females (this accepted among several breeders and tested) germinating on a heating pad will have a higher male ratio in most cases, but will also germinate faster and perhaps at a better rate but that last part I don't have any info on.


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## ISK (Dec 13, 2014)

Grojak said:


> germinating tems mater… colder temps have proven to make more females (this accepted among several breeders and tested) germinating on a heating pad will have a higher male ratio in most cases, but will also germinate faster and perhaps at a better rate but that last part I don't have any info on.


in this experiment, all seeds were germinated exactly the same...so in this case germination temps were not a factor.


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## ISK (Dec 13, 2014)

THE KONASSURE said:


> if you want males then run high temps with low humidity, and give more then 16 hours light and feed low N and higher pk and let them get dry before watering


agree with the high temp and low RH but the most would say more hours of light as I did with 20/4 in the male room


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## THE KONASSURE (Dec 13, 2014)

yeah once you go over 14 hours light you start to get a chance of more males over 18 and even if you do everything else correct in regards to aiming for females you`ll still risk more males, idk I`ve always tried for females getting males seemed to be easy when you don`t want them 

Had some cheap seeds once and they were coming up over 90% male


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## rohis (Dec 14, 2014)




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## ISK (Dec 14, 2014)

@rohis thanks for the post....I'm not as 100% sure as the dude in the video, as I would not say this is an absolute certainty but as mentioned the chart does have merit 

I was really hoping the female friendly room would have produced all males, but since it didn't it tells me the environment just may play a factor....but why did all the plants in the male friendly environment become female.

I have proven to myself that the female friendly environment most certainly produces healthier plants, so I will continue with those conditions in future grows


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## waterdawg (Dec 14, 2014)

We can only hope Myth Busters take up the challenge.


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