Can the Environment influence the Gender?

[ISK]

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

 

[bf80255]

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

 

[neonknight420]

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.

 

[Sativied]

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...

 

[ISK]

@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?

 

[Sativied]

@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.

 

[bf80255]

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

 

[neonknight420]

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.

 

[BWG707]

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

 

[neonknight420]

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.

 

[ISK]

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 )

 

[neonknight420]

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.

 

[ISK]

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....?

 

[bf80255]

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

 

[BWG707]

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.

 

[bf80255]

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

 

[harris hawk]

Generally the darker colored seeds have better germination rates

 

[neonknight420]

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....?

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.

 

[ISK]

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`

 

[Stompromper]

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.