Im 18/6 this time cause i was 24/0 last time. Next time i Might try 20/4 I found this post somewhere else and wondered if yall thought there was correct info or is this bullshit? ''I am a biology major currently taking a plant physiology course and I can tell you, at least according to my botanist professor, that plants will not benefit from the extra 6 hours of light in any meaningful way. Their stomatic gas exchange occurs during the dark period and while they may induce this behavior during constant light anyhow, there is something they can NOT do in 24 hour light: Their "dark" reactions!!! A plant has 2 photosystems and both light and dark reactions! The plant's electron transport chains will be active during light periods to "harvest" the light into [FONT=verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif]chemical energy[/FONT]... Now, this energy will be stored for use at night! At night, the plant uses that stored energy for input into the Calivin Cycle! The Calvin Cycle is the MOST IMPORTANT metabolic pathway in a plant and it finally can convert the chemical energy into useable sugars with the waste byproduct being O2. Basically, 18/6 is really the only choice *** 24/0 will allow for a forced Calvin Cycle, but the plant will need to expend MORE ATP and NAD+ to get the same singular glucose molecule... more work for same result = less vigor! Fo' real.. let us put this to rest as Mother Nature is the best scientist there is! Peace ''
Dark reactions occur even in light. They occur in the stroma and are only called dark reactions because they are light independent, which is misleading because darkness isn't required. The 24hr lighting doesn't really help or hurt much.
I am no EXPERT...But I am VERY CONFIDENT that the 24 hour light cycle theory has been tested specifically on Cannabis. I do not have the stats in front of me but there were clear growth indicators that showed growth is effected positively when given 24 hours during VEG. It's hard to tell I suppose by the strain etc...But I could swear this debate was put to rest decades ago???it has gone far past urban legend status...?
Yes you can get more vegetative growth from the 24hr cycle though it's not a whole lot, just like with 18/6 the roots will be somewhat larger. even theoretical you can only get 25% more growth from the 24hr vs 18hr. If you don't understand how that comes about it assumes constant growth rates and if you have 6 hours of extra lighting, 6/24=.25, you have that much more extra growth.
What do you think of seedling/veg for 30 days at 18/6 and then run the the light 24/7 to power veg them. In theory there should be a huge root sysytem to grow a huge plant.
Might as well stick with the 18/6, even if the root system difference isn't a whole lot the more roots the more nutrients you can uptake and the bigger buds you can potentially get. I've had pretty similar yields with 24 and 18 with the same veg time though the 18 pretty much always gives me fatter buds. The most difference will be seen in soil plants. With HYDRO you can actually get bigger yields with 24hr because you have more budsites, and even though the root system may be a bit smaller the plant has ideal root conditions for good nutrient assimilation. Think about soil and hydro and how nutrient burn appears, the hydro plant will show symptoms and recover much quicker. Though I think 18/6 is the best because it doesn't strain the plant at all. Because with a 24hr cycle the plant is trying to do everything at once. Normally during the light cycle the plant grows and builds it self and is focused on that instead of photosynthesis. This can be seen if you take a healthy plant from a lit area and put in a dark area. As the plant depletes its stores it will continue to grow, even in the dark and will actually stretch in search for light, hell you see it with the 12/12 switch. Root growth isn't dependent on the dark but the dark does help it to occur.
Well there you have it like my all over the place discussion was getting at, some darkness is better than none. Thanks tC and Useless. I had completely forgot about useless' post about that.:roulette:
Well I am no expert but it seems to me stress can play a factor In sex. I base this on a few things i noticed in my 24/7 grow First i had 13 --11 were girls. Now if its purely gentics they spraying them with methel did not make them trun male[got that off roesethals site] anyway its bull shit imo Now Its possible i just got unlucky, my temps were high . Its just too soon for me to form an opinion, but Im liking 18/6 better though the plants are not as big as 24/7 at this time they are pretty close. Now can a plant give off O2 with 24/7? I dunno, it would seem plants need some dark to do plant things. Well I guess in 5-10 years i will be able to formulate an opinion based on experience
I look at it like this. Every plant on Earth developed to utilize a night cycle so you should have some type of night cycle in there, also each light cycle is good for different things. If you want tight nodes, constant intense light. If you're looking to do clone to flower, you want a little stretch so you have some extra stem length to work with, and in that case, shorter light cycles and more distance from the light helps. Just keep screwing around. You will find the lighting schedule that matches how you grow.
I'm no biologist, nor a botanist, but I am a software developer, and a while back I did a simulation of a space station with a biological system (i.e., plants) for life support and food. I had data for all the plant species NASA was considering for use in space. The design goal was to get the most amount of oxygen and food out of the plants with the least amount of energy. What I learned was that every plant is a little different. For some plants, like wheat, the more light the more growth, so they are best grown with a 24/0 light cycle. For others, like soybeans, growth decreased without enough dark time, and the optimal amount of dark varied with species. Bottom line is that most plants require at least some dark time to maximize their growth, but not all. With respect to cannabis, I saw a study a while back, don't remember where, that showed that 20/4 was optimal. 24/0 and 18/6 were somewhat less optimal and about the same as each other. In other words, yield increases with a longer light cycle up to 20 hours, then starts dropping off again with more than 20 hours of light.
