Can stress to a seedling cause it to end up being a male?

[Irotas]

Can stress in the seedling stage from regular seeds cause it to end up being a male?

Or is sexual determination only influenced by stress later on in it's life?

 

[HuffnPufferfish]

in short yes

 

[Irotas]

in short yes

Thanks for the reply, do you have a source that states anything about this subject? I tried finding something but couldn't.

 

[metsäkana]

is there research papers made about conditions what will trigger it easier or just all stress in short...?

 

[Big Sur]

As said above, the simple answer is yes. I have read many articles/books on this and there are time windows when the phenotype sex is determined in a Cannabis plant. During that time females can be stressed into becoming herms or males (influenced by light -kelvin temp and day length-, nutrients in the soil, temperature, humidity, dry/wet soil conditions). Some say that time starts when they sprout, others say the critical period is between the 3rd and 4th weeks of growth. At that time genetic females can become expressed as pheno males, especially if they are stressed. You can also stress post-harvested re-vegging plants to herm and throw male flowers. I have seen that done myself. There are also chemicals that will force males to express themselves as females, and chemicals that will force female plants to express themselves as males. Oddly though, I have yet to get a female clone cutting to flip to being male on me after making hundreds of clones. I would like to... then I could self cross these guys and gals and get seeds.

 

[metsäkana]

ok i had 0fertilizer temps like over +31c, fungus gnats and small containers before i planted outdoor this year then temperatures hit almost forst and plants turned into white and still most of them where female so i dont belive its stress becouse that much stress all would be then males? XD

also soil had damping off i cant think much more stress only moose can eat it half and that did not happen but still i think it would become out female male about 50% each

and i cutted root with transplanting them soil was so compact

 

[Irotas]

As said above, the simple answer is yes. I have read many articles/books on this and there are time windows when the phenotype sex is determined in a Cannabis plant. During that time females can be stressed into becoming herms or males (influenced by light -kelvin temp and day length-, nutrients in the soil, temperature, humidity, dry/wet soil conditions). Some say that time starts when they sprout, others say the critical period is between the 3rd and 4th weeks of growth. At that time genetic females can become expressed as pheno males, especially if they are stressed. You can also stress post-harvested re-vegging plants to herm and throw male flowers. I have seen that done myself. There are also chemicals that will force males to express themselves as females, and chemicals that will force female plants to express themselves as males. Oddly though, I have yet to get a female clone cutting to flip to being male on me after making hundreds of clones. I would like to... then I could self cross these guys and gals and get seeds.

Thanks for that info, I would just like to know for sure whether the time starts when they sprout or later on like you stated. I have experienced herms, but I have never seen a female reverse and turn completely male.

 

[dank.frank]

Sexual determination happens in the seed. A plant is either male or female before it is ever germinated, XY or XX, respectively. It is a result of which plants pollen humped which plants stigma. M/F ratios, generally average out once you sprout large lots of seed (2,000), to be 50-50. Again, Punnett Square, XX x XY = XX, XY, XX, XY.

You can not, technically, "change" that.

So, if you happen to sprout a pack of regular seeds and you get 9 out of 10 females, you just got lucky and beat the odds. At the same time you sort of know there is a pack of seeds someone got that is more than likely it's counterpart, 9 out of 10 male. (There are exceptions to everything. Every so often a cross will result in a higher than average ratio, either direction. It is a unique and desired "trait" that breeders seek in breeding parents.)

Any breeder that is offering replacement seeds for poor M/F ratios in seed is honestly being extremely generous and patient with a consumers irrational expectations because they simply forgot the basics of genetics from high school biology class. (my opinion)

For these reasons, I do not think having improper (or proper) conditions will affect the outcomes of m:f ratios in seed.

If you had asked me that a decade ago, uncounted numbers of seed prior, I might have said, yes, and given a list of 5 environmental conditions to focus on to increase the number of females. That old list from OvG forums. I don't post that anymore.

FWIW - I've seen plants, here on IC, that are "male" from feminized seed. Skunk Va s1 "male" found by the hummus monk. The plant grows, behaves, looks - EXACTLY - like a male plant. However, it is technically impossible, genetically speaking, for a feminized plant to be a male. XX x XX = XX, XX, XX, XX .... Punnett Square.

I have seed made from that "male" and I'm likely going to have it tested to see if it is in fact, XX, seed stock, or if it is XY. If it is XY, you have to assume there was a contamination from another plant, an actual male, during pollination, Which would be the most logical reason for finding what appears by all visual and behavioral means to be a true male in feminized seed.

This is a plant that is technically, a 100%, actual, hermaphrodite. Much of cannabis in the wild, self pollinates. It's through hybridization and selection for specific traits that we have "drug" cannabis that DOESN'T self pollinate. Sam the Skunkman has always said there are very few "true" females, that even when introduced to chemical means will not reverse or show male traits.

Regardless of what you see happening physically to the plant, it does not however, change the genetic DNA of that plant. When a female plant produces male flower sacks in early flower on it's lowers or bananas late in flower in the colas, that is still XX. It's sex has not changed.

So no, you can not, technically, alter the sex of a cannabis plant by simple environmental means.

Science, bitch! (just a Breaking Bad reference, for those that get offended easily!)



dank.Frank

 

[dufous]

extreme conditions can cause genetic females to express as males

favorable conditions will not cause a genetic male to express as female

 

[metsäkana]

omg no extreme can cause it belive what frank say

 

[Big Sur]

Regardless of what you see happening physically to the plant, it does not however, change the genetic DNA of that plant. When a female plant produces male flower sacks in early flower on it's lowers or bananas late in flower in the colas, that is still XX. It's sex has not changed.

So no, you can not, technically, alter the sex of a cannabis plant by simple environmental means.

Science, bitch! (just a Breaking Bad reference, for those that get offended easily!)

dank.Frank

It is true that you cannot change a MJ plant's genetic sexual identity once it is established in the ovum. What we are calling flipped males and herms here are technically still genetic females, but they are phenotype males and herms. They look like males, and bloom like males (with staminate flowers). They do not produce female buds. You can get females to flip and express themselves as males given the right (poor) environmental exposure, or given certain chemicals. You can also do the opposite. Females can and do flip to expressing themselves as being all male early on, or herms later on, and it also happens in the wild.