UV during Veg stimulate male expression?

Firstly: please note the question mark in the thread title.
This is my experience and entirely anecdotal and of course informed comments are solicited.

I recently hung a GeekBeast 650 pro in my tent. I confess I am such a stoner that I put the thing together and didn't notice or didn't remember seeing the switches for UV and IR. At the time I thought all the GeekBeast LEDs were controlled by wifi or bluetooth (I hate bluetooth). So I hung the beast in my tent in an orientation that placed the wiring close to the end wall so I could easily mount the driver exotent. However this made the UV and IR switches hidden against the far wall of the tent.

The plants were in about the third week of veg when I did this. In a few days I noticed that many of the fan leaves has liquid on the surface.
a week later I saw the effects of light burn all over my nineteen seed-born lovelies. I was running the beast at one hundred percent brightness. So I thought that was the problem. I turned it down to 60 to 70%. Still light burn. I finally discovered the hidden switches and saw that the UV was on 16hrs a day.

Long and short of it: out of 19 plants, 4 of them turned out female. All of the females were on one edge of the light were the brightness was the lowest.

In all my decades of growing from seed, I have never seen a ratio of m/f like this. In fact I never had less than about 60% females and most of the time it was better. Now before anyone points it out: I am well aware that 19 plants are virtually statistically insignificant BUT the fact that the four females were all in the least bright area of the light, all of them, along the one corner and edge, makes me very suspicious that the burn caused by UV during veg somehow stimulated male expression.

That would be news to me but I just had 6 of 8 auto fems come up male with no UV light added. Under a 600W MH or outside but even in the sun where there's a decent amount of UV good fems should not come up male.

OldMedUser said:

That would be news to me but I just had 6 of 8 auto fems come up male with no UV light added. Under a 600W MH or outside but even in the sun where there's a decent amount of UV good fems should not come up male.

Click to expand...

I wouldn't get my seeds there anymore that's for sure. What was the source?

Excessive UV can cause female plants to hermi. They need to be exposed to it gradually at an appropriate distance else fertile nanners will be popping out everywhere. Don't know about UV causing 100% male expression though.

JacFlasche said:

Firstly: please note the question mark in the thread title.
This is my experience and entirely anecdotal and of course informed comments are solicited.

I recently hung a GeekBeast 650 pro in my tent. I confess I am such a stoner that I put the thing together and didn't notice or didn't remember seeing the switches for UV and IR. At the time I thought all the GeekBeast LEDs were controlled by wifi or bluetooth (I hate bluetooth). So I hung the beast in my tent in an orientation that placed the wiring close to the end wall so I could easily mount the driver exotent. However this made the UV and IR switches hidden against the far wall of the tent.

The plants were in about the third week of veg when I did this. In a few days I noticed that many of the fan leaves has liquid on the surface.
a week later I saw the effects of light burn all over my nineteen seed-born lovelies. I was running the beast at one hundred percent brightness. So I thought that was the problem. I turned it down to 60 to 70%. Still light burn. I finally discovered the hidden switches and saw that the UV was on 16hrs a day.

Long and short of it: out of 19 plants, 4 of them turned out female. All of the females were on one edge of the light were the brightness was the lowest.

In all my decades of growing from seed, I have never seen a ratio of m/f like this. In fact I never had less than about 60% females and most of the time it was better. Now before anyone points it out: I am well aware that 19 plants are virtually statistically insignificant BUT the fact that the four females were all in the least bright area of the light, all of them, along the one corner and edge, makes me very suspicious that the burn caused by UV during veg somehow stimulated male expression.

Click to expand...

Interesting hypothesis, but i would wager it likely has nothing to do with that light. Looking at the specs for that light they add some near uva, violet, around 390-400nm. Thats no where near stress levels that may cause unwanted funk in the grow.

Its not the UV, its just light stress in general. I have the 480 down to 60 percent in a 4x4 at 4 ft away from canopy. the beast pro is over kill and should only be used for commercial settings unless your doing a low profile room. I use UV all cycle bulbs produce UV all cycle. Thinking its a sectrum issue is not possible. they are designed to use all color spectrums from the sun, even green plays a roll for lower strength photons to travel further.

t5 6500k common use veg bulb and absorption ratio by spectrtum

I too am trying to find the sweet spot for my 2x Geek Beast Pros in my 4x8.

My plants endured a bit of light stress as well. I've got the lights down to 60% and about 2 feet above the canopy and they seem very happy. Plants are still in veg, I have not introduced any UV or IR yet.

I would say that the Geek Beast being overkill for a home grow application hopefully speaks to it's value. I have friends who have spent 3x as much as I did on lights. It feels pretty good to pay a fraction of that and have to crank the lights down because they're too powerful.

JacFlasche said:

I wouldn't get my seeds there anymore that's for sure. What was the source?

Click to expand...

I just ordered another pack of different CBD seeds last night from the guy. He's a breeder down in WA state that basically gives the seeds away and you just pay for postage named Sebring. I've grown out a nice CBD strain of his called Sebring's Revenge and got 4 of 4 girls from the 4 I planted so no problems there and the meds I made with it works great. He's puzzled as hell about why those ones went off the rails too and it's hard to bitch about free seeds. lol

He has a community garden for lots of heirloom veggies like tomatoes and supports the poor in his area so I can't really say anything bad about the guy. Even sent me some free chemicals to make STS with so I could make my own fem seeds and share those with the community at OverGrow and elsewhere. I've since sourced my own chemicals and have sent out a few packs to other growers to pay it forward. Enough to make 10L with and probably cost me $5 including postage to send it.

Here's a link to his sold-out seed page. Sebring's Seeds and Salves.

I repeatedly expose my girls to 280nm, 365nm 395nm, 420nm and reptile UV lights to the point of burning the leaves and haven't seen them hermie.

Are you going to try to repeat the exposure and see if you can repeat the results?

nunyabidness420 said:

I repeatedly expose my girls to 280nm, 365nm 395nm, 420nm and reptile UV lights to the point of burning the leaves and haven't seen them hermie.
View attachment 4670130
Are you going to try to repeat the exposure and see if you can repeat the results?

Click to expand...

No way. LOL So are those small yellow dots the beginning of a burn? I wish that was all that happened to my plants. They actually went from yellow tips to yellow outline to red yellow leaves that didn't fall off. I have turned the UV off until harvest and it took weeks for them to grow enough new green to overcome the burn.

OldMedUser said:

I just ordered another pack of different CBD seeds last night from the guy. He's a breeder down in WA state that basically gives the seeds away and you just pay for postage named Sebring. I've grown out a nice CBD strain of his called Sebring's Revenge and got 4 of 4 girls from the 4 I planted so no problems there and the meds I made with it works great. He's puzzled as hell about why those ones went off the rails too and it's hard to bitch about free seeds. lol

He has a community garden for lots of heirloom veggies like tomatoes and supports the poor in his area so I can't really say anything bad about the guy. Even sent me some free chemicals to make STS with so I could make my own fem seeds and share those with the community at OverGrow and elsewhere. I've since sourced my own chemicals and have sent out a few packs to other growers to pay it forward. Enough to make 10L with and probably cost me $5 including postage to send it.

Here's a link to his sold-out seed page. Sebring's Seeds and Salves.

Click to expand...

We need more free seeds. I wish I had the seeds from a bag of punta roha that I came across in the seventies. Still the best weed I have ever seen.

illmatik said:

I too am trying to find the sweet spot for my 2x Geek Beast Pros in my 4x8.

My plants endured a bit of light stress as well. I've got the lights down to 60% and about 2 feet above the canopy and they seem very happy. Plants are still in veg, I have not introduced any UV or IR yet.

I would say that the Geek Beast being overkill for a home grow application hopefully speaks to it's value. I have friends who have spent 3x as much as I did on lights. It feels pretty good to pay a fraction of that and have to crank the lights down because they're too powerful.

Click to expand...

I am in about the third week of flowering and am cranking it up to 80 intermittently. Today I had it at 100 for like an hour or two at about ten inches. A bit higher is probably better to avoid hot spots, because my lux meter just shows wildly varying intensity in different spots. I ran it at about 50 to 60 for veg. Now I am pushing it a bit. I get concerned when I see the leaves praying a bit too intently. But I agree, it is better to be able to run the light at lower power, will probably make a big difference to its longevity.

BHippyAZ said:

Its not the UV, its just light stress in general. I have the 480 down to 60 percent in a 4x4 at 4 ft away from canopy. the beast pro is over kill and should only be used for commercial settings unless your doing a low profile room. I use UV all cycle bulbs produce UV all cycle. Thinking its a sectrum issue is not possible. they are designed to use all color spectrums from the sun, even green plays a roll for lower strength photons to travel further.

Click to expand...

I think you are correct.

graying.geek said:

Excessive UV can cause female plants to hermi. They need to be exposed to it gradually at an appropriate distance else fertile nanners will be popping out everywhere. Don't know about UV causing 100% male expression though.

Click to expand...

I think these guys are right and it is just too much light.

JacFlasche said:

No way. LOL So are those small yellow dots the beginning of a burn? I wish that was all that happened to my plants. They actually went from yellow tips to yellow outline to red yellow leaves that didn't fall off. I have turned the UV off until harvest and it took weeks for them to grow enough new green to overcome the burn.

Click to expand...

No. that clone and the mother it came from had those little white balls ever since it was a seedling.
Someone told me some strains are like that so I didn't think much of them.
I hadn't noticed they had turned yellow till you mentioned it.

JacFlasche said:

We need more free seeds. I wish I had the seeds from a bag of punta roha that I came across in the seventies. Still the best weed I have ever seen.

Click to expand...

The first buds I ever grew back in '78 were Thai Stick, Maui Wowie and Jamacian Red Hair plus a couple of Mexican sativas from some brick pot. I'd surely love to have at least the Thai Stick one. Pathetic buds at the time but I know I could do a much better job of it now.

OldMedUser said:

The first buds I ever grew back in '78 were Thai Stick, Maui Wowie and Jamacian Red Hair plus a couple of Mexican sativas from some brick pot. I'd surely love to have at least the Thai Stick one. Pathetic buds at the time but I know I could do a much better job of it now.

Click to expand...

I had a few lbs of Thai Stick back then. Everybody wanted to smoke it but almost no one wanted to buy it. But then at the time a z of weed was twelve bucks, then when Colombian came around it went up to twenty. And where I lived hash was much more available than weed. We had Moroccan and Afgani hash almost all the time. Then the Punta Roha came around -- just once where I was, and it was forty an oz, an outrageous price. Sure glad I bought it. I use to smoke one fatty per week when I visited my girlfriend at college. I remember the first time I smoked Maui, I could not get off the floor. It was the first time that happened since I scored some Wacky Weed at OC Maryland in the seventies. Personally I like the way herb used to be named, by where it came from, more than the new "cool" names made up by wannabe ad-men.

JacFlasche said:

I had a few lbs of Thai Stick back then. Everybody wanted to smoke it but almost no one wanted to buy it. But then at the time a z of weed was twelve bucks, then when Colombian came around it went up to twenty. And where I lived hash was much more available than weed. We had Moroccan and Afgani hash almost all the time. Then the Punta Roha came around -- just once where I was, and it was forty an oz, an outrageous price. Sure glad I bought it. I use to smoke one fatty per week when I visited my girlfriend at college. I remember the first time I smoked Maui, I could not get off the floor. It was the first time that happened since I scored some Wacky Weed at OC Maryland in the seventies. Personally I like the way herb used to be named, by where it came from, more than the new "cool" names made up by wannabe ad-men.

Click to expand...

I was driving cab in Calgary back in the late 70s and middling a lot of pot/acid/mda back then. Was mostly mexican dirt pot in bricks but then the Thai showed up and I was buying lots for resale and getting $20/stick which was just 2.5g each or so. Just a little pinner got 4 people fucked right up tho and the high was so much better it just flew out the door. We had a lot of hash back then too coming in from Montreal mostly. Nice Temple Ball and lots of Lebanese compressed dry sift hash of various colours. Hot-knifing nerds of gummy hash until that last hit knocks you out and you wake up on the floor with everybody laughing at you. lol

I remember in an old Harold Hedd comic or it might have been The Fabulous Furry Freak Brothers a lecture about the bogus names applied to pot back then to make them more appealing to the nOObs. I'd get losers in my cab trying to sell me dirt pot under an assumed name and usually end up selling them some Stick or Maui or maybe some 'cid. The hookers on the strip were great for moving product and with 6 bars that held 500+ people each in one block there were lots of customers for all businesses concerned.

Why doesn't pot hit like that anymore? Just too many hits under my belt? I still get right fucked up if I do a bit too much but it's more a wait until it settles down rather than an OH YEAH MAN! kind of thing.

Too many people in the seed marketing game for years now. Flipping F1s for the same price as well bred stable strains is a total rip-off. Just mixing everything up into the same bland offerings everybody else is selling. Making mongrels of them all but a few stand-outs. Shopping for seeds is a special kind of hell so I never do that. I got plenty to grow out without having to buy them. Swapping with friends in forums and IRL has me wishing I had less to choose from. So many strains, so little time!