ttystikk
Well-Known Member
@torontoke just did a thread on this, with less than stellar results. I'm not buying the idea that we can give the plants half the light interval they've evolved to receive and still expect decent results?
using UV to put plants to sleep
- Thread starter NWbordergrower91
- Start date
testiclees
Well-Known Member
Agree, those posts that mention a plants ability to get a full quotient of photons in 8 hours seem suspect.
Although the effect of hastening a full darkness response through far red is well studied, pretty sure.
ttystikk
Well-Known Member
I've repeated asked if the normal cooling of HID lamps will trigger this response. They glow plenty hot after shutoff for quite some time, mostly in the IR range. This would seem to be just what they're looking for? Or, not? Why?
testiclees
Well-Known Member
It does seem like the glow would give the effect if it were 730nm for a few mins.
Did you enquire on the far red thread?
Did you enquire on the far red thread?
ttystikk
Well-Known Member
I did. No one seems to know.
torontoke
Well-Known Member
Not sure exactly what u are pulling me into or what results would be considered steller or not.
ttystikk
Well-Known Member
I tagged you because you just did a run with a short day cycle- and as I just saw you respond to another posting, you got about 75% of the full run's yield. I'm not sure that's enough to keep looking into the technique. Figured you might have some useful input to the discussion!
torontoke
Well-Known Member
Actually then you and i disagree completely. I think getting 75% yield out of 6-8 hrs is definitely worth me to keep looking into it.
Especially switching to 8hrs and running three flower rooms with one light.
75% yield from 50% of the light is good math and reason to experiment further.
torontoke
Well-Known Member
Well common sense should tell anyone that reducing the light period is going to produce a reduction in yield. However if the reduction of yield is less then the reduction of light its worthwhile.
So using tty's own idea on my thread and you used one light to do three crops it would increase your yield by 30-50% while only costing 25% more than 12/12 if that makes sense.
Edit: and the reduced light schedule actually made the plants finish 5 or so days earlier aswell
So using tty's own idea on my thread and you used one light to do three crops it would increase your yield by 30-50% while only costing 25% more than 12/12 if that makes sense.
Edit: and the reduced light schedule actually made the plants finish 5 or so days earlier aswell
Last edited:
Dr. Who
Well-Known Member
Yes, that IS where the deep reds (aprox 690 - 700nm and above) are generated using HID lighting......I found this out by talking with several different bulb makers - that actually make their bulbs here in the US.
I too got around >75% at 6 and when maximizing lumin out put by every way I could while still running 1K's (Jupiter 6 hoods = 20% more reflected light, new bulbs {155,000} metering out at 179K to 183K per {Interesting spread - bulb variation}). I got very close to 90% at the the 7 hr point test.
Conversely, On the 730nm LED - Giving you 2 more hrs of lights on time. The rise in yield was minimal from my normal 11 and was not (mathematically) worth the added electrical cost!
So, another point of view by testing from another member, qualifies your findings....Also point given on the 730nm LED value. Hell the cost of the 2 LED's I bought were not even worth it....Another "collective" member bought them from me to do his own testing on the subject, following standards of a similar test at MSU on C3 fruiting plants in the squash, Bean and tuber family's.
Still awaiting results on that..
Doc
wrong. indoor grows miss sunset and sunrise, which are important environmental signals.
there is an interplay with far red light and deep red light that helps the plant to keep track of daytime and nighttime.
I do agree tho, Rosenthal is poppycock
skunkd0c
Well-Known Member
The plants imo are sleeping while the light is still on, if you leave lights on for 24 hours per day
or even 16-18 per day i notice that at around 15 hours of light during veg , all the leaves often severely droop downwards while still under strong hid lighting
some newbies even think the plant has wilted when this happens lol
peace
yeah I get what your saying, they do try to follow a normal daily cycle despite 24 hour light, But keep in mind plants do not sleep.
skunkd0c
Well-Known Member
lol, i know that, but its so cute when they look like they are sleeping
they will still do it under 16 hours, they know when they have had enough and want a rest
when they want light, the leaves will often twist in all sorts of positions to get the best angle
i say they are drooping down like that for a good reason , and it seems to happen at the 15 hour mark
lol I reserve cute for my girls, otherwise they get jealous.lol, i know that, but its so cute when they look like they are sleeping
they will still do it under 16 hours, they know when they have had enough and want a rest
when they want light, the leaves will often twist in all sorts of positions to get the best angle
not sure but I don't think it will work, has too much orange\deep red light in the glow.
Dr. Who
Well-Known Member
Ah HA! You have now seen a classic example of the light saturation point in effect!
I have to ask Skunk,,,how many lumins is the lighting producing? Sounds kinda slow - 15 hrs. More then kinda! Well then you say "severely." That means that they actually reached it well before that and are struggling to "recover" from the cellular changes that the "saturation" has caused or begun...
While a Cannabis plant does not "need" a lights out time to grow. Growth is more balanced and effective when given some!lol, i know that, but its so cute when they look like they are sleeping
they will still do it under 16 hours, they know when they have had enough and want a rest
when they want light, the leaves will often twist in all sorts of positions to get the best angle
i say they are drooping down like that for a good reason , and it seems to happen at the 15 hour mark
Light saturation will cause reduced effective use of the light! Photosynthesis declines as does the plants use of Co2 in a correlated way....Cells change on the peptide level to actually protect the plant from the light!
Turn out the lights - give your plant a real rest. The cells will use the time to change back to the most effective they can be...
Doc
(cool observation sd)
skunkd0c
Well-Known Member
Personally mate, i would agree, i feel the extra benefit that i see from the 24 hour thing is from consistent heat rather than the extra light helping
when i started growing 16 hours was recommended for veg, this changed to 18 pretty quickly
i have heard that some rare types can even flower on 16 hours, i have never seen this myself
in the uk lights off temps can be 58-65f in an unheated room, with lights constantly on, the temps would be a steady 75f in the colder months
this would be my main justification for leaving the lights on all the time
i have always thought that once the leaves start drooping they would not be photosynthesizing to their maximum potential anyway
i would observe the drooping thing, mostly between weeks 3-5 of veg
when they are growing fast and spitting out new leaves daily
i have seen this under hid and low lighting , so i do not think it is the intensity
it happens when they are growing very fast
also, i forgot to mention, they perk right back up around 2 hours before the lights come back on
observing this, it is like, they are very tired from a hard days growing
they take themselves to bed early after 15 hours
they are so eager to get up the next day to start growing again
the leaves all return back to their normal positions, waiting for the light to come on
so 16 on and 6 off would be the natural pattern they seem to follow at this stage
of maximum veg growth
peace
Last edited: