DWC Mistakes I made

hotboxhatchback said:

thanks for the video, purpdaddy. very enlightening indeed.

have you tried adding a uv light yet? did you get noticeable results? anyone else?

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There were studies conducted by universities during the mid-late '80s that showed linear increase of THC in drug-type cannabis with additional UVB exposure.

KaliKitsune said:

There were studies conducted by universities during the mid-late '80s that showed linear increase of THC in drug-type cannabis with additional UVB exposure.

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Cite?

Honestly, I don't think the difference is big if any.. I watched all the viedos and the guy just makes shit up at times, like he does not quite understand it. My wife is a research scientist that works in cell culture. Ill have her watch it and tell me whats up..

Hereis an article that if I read it correctly says that UVB lowers crop weight in rice, but they tested Indica rice..lol

We found that UVB radiation reduced tiller number, fresh and dry weighs, and the amounts of total leaf nitrogen, soluble protein and Rubisco in leaves of rice (Oryza sativa L.). There were cultivar differences in the sensitivity to the inhibitory effects of UVB radiation among indica, javanica, and japonica rice ecotypes.

http://abstracts.aspb.org/pb1997/public/P45/0979.shtml

olosto said:

Cite?

Honestly, I don't think the difference is big if any.. I watched all the viedos and the guy just makes shit up at times, like he does not quite understand it. My wife is a research scientist that works in cell culture. Ill have her watch it and tell me whats up..

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UV-B RADIATION EFFECT ON PHOTOSYNTHESIS, GROWTH AND CANNABINOID PRODUCTION OF TWO Cannabis stavic CHEMOTYPES: by John Lyndon, USDA-ARS, Southern Weed Science Laboratory, P. O. Box 350, Stoneville, MS, 38776, USA: Alan H. Teramura, Department of Botany, University of Maryland, College Park, MD, 20742, USA., & C. Benjamin Coffman, USDA-ARS, Weed Science Laboratory, AEQ, I, Beltsville, MD, 20705, USA: Received August 29, 1986, accepted February 24, 1987: page 201 Although the mechanism is unknown, a relationship exists between cannabinoid content and the attitude altitude at which C. sativa is grown. Mobark et al., (197 suggested that the high-altitude environment was responsible for an increased population of propyl cannabinoids in plants grown in 1300m. The average total cannabinoid content of wild, mature (flowering) Indian C. sativa from elevations between 250m and 1000m was 2.43% (by dry weight); between 1000 m and 2000m was 3.01%; and above 2000m Was 1.39% (Turner et al., 1979). The cannabinoid content in four out of five of these mature Indian C. sativa variants decreased when grown at sea level in Mississippi, USA. One likely factor which may be of significance to cannabinoid production in both high-altitude and tropical environments is ultraviolet radiation. page 202 Pate (1983) reported that C. sativa populations originating from high UV-B environment contained little or no cannabidiol (CBD) but high levels of delta 9 - tetrahydrocannabinol (delta 9 - THC), while the opposite was true for population from low UV-B environments, and proposed that the two distinct C. sativa chemotypes (drug and fiber) evolved as a result of selective pressures brought about by UV-B radiation. Fairbairn and Liebmann (1974) reported that the delta 9 - THC content of leaf tissue from UV irradiated greenhouse-grown drug-type C. sativa was 23% greater than non- irradiated greenhouse-grown plants. However, neither the spectral distribution nor the daily dose of UV radiation . The objectives of this study were to test (a) The physiological and morphological insensitivity of both the drug and fiber types of C. sativa to UV-B radiation; and (b) to correlate this insensitivity with a change in production of delta 9 - THC or CBD in drug and fiber type plants, respectively. Material and Methods Page 203 Results....Only the delta 9 THC content in leaf and floral tissues of drug type plants increased significantly with UV-B radiation. page 204 Discussion page 205 The results presented here indicate that both types of vegetative C. sativa are physiologically and morphologically insensitive to UV-B radiation. The increased level of delta 9 - THC found in leaf tissues upon UV-B irritation may account for this insensitivity on the drug type plants. However, fiber-type plants showed no comparable change in the level of CBD which has similar UV-B absorption characteristics). Thus, the contribution of cannabinoids to the UV-B insensitivity in vegetative C. sativa is equivocal. Perhaps the background levels of CBD present in the fiber-type tissues were sufficient to protect the plant from UV-B radiation. Alternatively, other UV-B absorbing compounds such as flavonoids may account for this UV-B insensitivity. Flavonoids are the principle pigments associated with UV radiation greening in plants . Barrett et al (1985) reported the concentration of Cannflavin A (a flavonoid from C. sative) was similar in drug and fiber type leaf tissue, whereas Gellert et al (1974) reported relatively more flavonoids in drug than fiber type plants. Whether the quality and quantity of flavonoids in leaf tissues of the chemotypes in this study were sufficient to account for observed UV-B insensitivity was not determined. It should be pointed out, however that one should be cautions when extrapolating from greenhouse to field conditions in UV-B studies. In addition, when considering the distribution of C. sativa, one cannot overlook the fact that it is one of the oldest cultivated plants known to man. Thus, its present distribution may possibly be an artifact of man's cultural practices. In conclusion, the delta 9 THC content in leaf and floral tissues of greenhouse grown drug-type C. sativa increased linearly with UV-B dose. Other cannabinoids in drug and fiber-type plants were unaffected by UV-B radiation. Both drug and fiber chemotypes were physiologically and morphologically tolerant to UV-B radiation.

http://www.hempforus.com/reseaag4.htm Go to this link and there you will find all the good educational articles that most would normally have to pay to read. All sources are cited at the beginning of each article so you can even check back with the researchers that conducted the studies, if you can find them.

Very cool, thanks!

So if im reading that then that means if your using uvb, you could see a 23% increase in THC?

olosto said:

So if im reading that then that means if your using uvb, you could see a 23% increase in THC?

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the excerpt says it was a 23% difference in the delta-9 thc content of leaf tissue.

it also says repeatedly that the testing used sativa. is it the same for indica?

I wouldn't know for indica. I'd assume since those are heavy resin producers that it might indeed do better.

And just for the record, 23% increase would be like going from 20 to 25%, no going to like 43%(we wish!)

i wanna get 2 of those uvb lights and run em just a couple hours during their lights ON cycle and see what happens!Has to make some kind of difference cause science says so.

the delta 9 THC content in leaf and floral tissues

It's in both. Mostly Trichomes.

Fucc man 25% THC content!Wheew..can you look at it and get high??LOL

I was under the impression, just for clarification, that nutes should not be given to clones that haven't rooted but once they have rooted it's fine to use nutes... And I agree roots to love air, I have a bubble stone under each plant and I have noticed the difference between using stones vs. not using them. However just don't let roots dry out.

We raise BEARDED DRAGONS, lizzards, and they require both UVA and UVB light. The book says the sun provides both, more of one than the other, depending on the season.

purpdaddy said:

Fucc man 25% THC content!Wheew..can you look at it and get high??LOL

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I've gotten some severe red-eye just looking at some Lebanese blonde hash. Just thinking about it got me pseudo-stoned.

I flower w/ hps and two 40watt 4' uvb 10.0 fluorescent tubes and I don't know if the uvb made it danker but my buds were quite good, even though the yield was a fail but I read some really bad advice, you know you see it around.

Someone (not to mention names) told me cutting off fan leaves is a good regular exercise because they do it.

I'm stoked on seeing that 23% figure because I no longer fear having wasted cash on my UVB lights.

One of the most knowledgable growers on this site, Al B. Fuct, says he cuts off the bottom 1/4 of the entire plant, not just the leaves, but all of the branches too.
He says he is not interested in the smaller buds, or popcorn buds. Me, I think it is a bad idea, I want all the buds I can get.

hey Roseman, you say to start your seeds right in the system. what kind of room temps do you have when you do this? also do you soak the rockwool, if so how long do you soak it and do you remove the plastic wrapping from the cubes? one more quick question, you say that tap water is fine but dont let it sit out. my tap water is about 150ppm and the ph is like 8-8.5. I always thought that you had to let it sit out to evap the chlorine is this not true or how do you feel about this? thanks for all info Rose. I am going to tribute my first grow to you and purp cause you guys did all the research and got the great info from the guys you have posted above. I now find it fairly easy to answer all my questions by just reading up on the two of you instead of endless searches.

polishfalcon420 said:

hey Roseman, you say to start your seeds right in the system. what kind of room temps do you have when you do this? also do you soak the rockwool, if so how long do you soak it and do you remove the plastic wrapping from the cubes?

My room temps during Winter, in the grow room closet with doors open, and with central Heat on, and 1400 watts of CFLS, are about 80 to 84 degrees. In summer, with the air conditioner on, they are about 79 to 82.
I do soak the rockwool, (safety experts say not to touch the rockwool cubes dry, but to dampen or soak them first) and I do let the feeder tubes trickle water to the cubes. I do remove the plastic from the cubes. I do soak the seeds in a cup of water for 12 hours first, before putting them in the cubes.

I also start two extra seeds in wet paper towels, in case I get a dud, or runt. I then put them two seeds in soil, in case I need them later, to transfer to the system.


one more quick question, you say that tap water is fine but dont let it sit out. my tap water is about 150ppm and the ph is like 8-8.5. I always thought that you had to let it sit out to evap the chlorine is this not true or how do you feel about this?

Many, many people argue wtih me about this, but I know what I am talking about. Back in the early 80s, I went to a school or class for two days, on Drinking Water. I had a job selling water filters. We would go to a home, and with a cheap common SWIMMING POOL WATER TEST KIT, we would show the prospect that their drinking water, their city tap water was not safe to swim in becuase it had too much clorine in it. And it certainly had too much clorine in it to be drinking. I sold a lot of water filters doing that. In the shcool, we learned that you can let city water from the tap flow onto the palm of your hand, and the clorine will instantly disapate, or evaporate. You can test this easily, by using a cheap swimming pool clorine test kit. The water will come out with a HIGH clorine level, then you can let some run over your hand into a cup and test it, and the clorine is gone.
I also own 14 books on growing pot and at leat two of them, one by Ed Rosenthal, says that city water is more than fine or OK for growing pot.

Allowing the water to sit out in the open, uncovered, is asking or inviting algae to come in. DON'T DO IT.

Take the water from your tap, let it run over the palm of your hand, pH test it and pH adjust it. Add your nutes then pH test it again, and adjust as necesary.


thanks for all info Rose. I am going to tribute my first grow to you and purp cause you guys did all the research and got the great info from the guys you have posted above. I now find it fairly easy to answer all my questions by just reading up on the two of you instead of endless searches.

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Thank you much, and I hope you visit our threads often. Purp sure is a grow expert now.

my temps were running 93 most of the day and get down to like 75 at night.I got my schedule to where the lights come on at night and cut off in the mornin.8:00-8:00

man i just soak up info on this BP like a sponge,You really have to read alot..my girl said when i first foung this site,i was on the computer researching growing more than she was getting her online degree.Thats dedication and you have to have the WANT for knowledge not just to grow,but have PERFECT grows.THATS what we strive so hard for.