Nah I just read and weed a lot.
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Hahaha respect that!
The best part for me is you not just reading but clearly understanding what you read and being able to apply it. Thats a skill we are losing it seems at times
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Sorry I need to add a bro-science comment regarding breeding for light.
I found an interesting article about " How much cloud affect photosintesis irradiance" and this test during two cloudy days.
Let’s back for one second to the idea of strains that need less light and let’s take into consideration Netherland where there are 32% of sunny days ( approximately) during summer and 68% of cloudy days.
If we assume that the sun produce 2,000umol a cloudy day give the plant 1,000. 50% in light reduction.
it makes me think that also in these conditions the strains developed in Netherland for short summer countries are actually developing very good.
Of course someone could perfectly argue that if you take the same strain and you grow it in Spain it will grow much much better ( is it true actually?)
Have you heard about VIC high works? I guess she/he was from here originally ( probably I am crossing data).
Another comment is related with light intensity and altitude.
What we can say about those landrace strains that are growing at 1,000m Vs those that grow at see level? I don’t think the sun intensity, radiation’s, etc is the same… Not sure which reflections bring this to the table.
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You ask all the best questions
Yes, can be. Here is an example spectra of the sun mid-day partly cloudy northeastern US late spring.
In this sample the PAR (400-700nm) measured as 1580 umol / m^2 s as captured by a spectrophotometer:
The solar irradiation will vary by location, environmental conditions, calendar date, and time of day.
For instance, here is what the DLI looks like based on latitude and day-year (estimated daily light received in Mols:
And how the amount of irradiation varies based on time of year, this is Ecuador (graph is rotated clockwise):
And, here is Sydney:
etc…
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Brilliant Northern.
Definetly tonight I won’t sleep 
Can you clarify the following?
1580 umol is not this a value perfectly achievable by LED lights?
You can achieve that but you’d probably want co2 supplementation as that may be a limiting factor.
My suggestion is to not go for that intensity indoors until you have several grows at a reduced intensity under your belt (if not already). That is a high intensity which brings with it other difficulties, such as heat. Also bare in mind, that the light intensity hitting the plant leaves (starting from the top towards the bottom) will be significantly different than the sun intensity (the rule of squares) … when using overhead lighting.
In addition, the yield -v- efficiency decreases with intensity such that double the intensity does not mean double the yield … in addition to any limiting factors (such as CO2).
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From one thing know ten thousand things
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Why even bother answering when @Northern_Loki is just spitting facts!!
Great answer, great pics!
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Im not sure about that. It might be a bad translation into english.
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I’m not too familiar with the fast plants as I haven’t grown any or done a lot of background research. My guess from the translation is that increased dark hours increase the density of the bud, but I bet that is related to some ruderalis genetics.
I’ll have to look into these more before I can say anything with true confidence, but I will try to get some of that done this week!
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You very much can breed for lower light performance. It’s a bit of a niche trait but one I value for specific lines and growing methods.
Such lines exist, even a few popular cuts perform better neglected in the corner than in a more primo spot right under the light. I don’t keep a list but I encounter good examples somewhat often reading through grow threads. Recently saw a grower confused as to why his top buds were so small while the rest of the plant had soda cans buds.
Vertical grows using stacked lights where top and bottom lights are consecutively turned on for 6 hrs take advantage of this principle. Heath Robinson himself showcased this many years ago with great success.
Even though these projects are secondary, I do believe this to be one important aspect to destroying theorical yield barriers.
When I first started selecting for low light performance i would hang a 1000w hps over a 8x8 area and watch which plant defeated logic.
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@Mithridate that’s some cool information! Im glad to see that works! Selections for stuff like low or high light are cool and complicated because of how much physiological and biochemical processes rely on it. I would love to talk sometime about what you see with your lines, this type of selection is likely rampant indoors and we don’t always have a clear idea of what the trait is. Id be interested to hear if you’ve noticed any trade offs with other traits in the low light environment. Really cool stuff!
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I think with ever more efficient lighting systems we are systematically culling plants that would perform better in lower light levels as they are “poor performers”.
So, hyper-efficiency should never come with a loss in quality. Objective is a net positive.
One draw back or limiting factor under low input would be long flowering/equatorial/nld lines and their need for the high light intensity. Low light breeding has a limited range of type of high… not saying it’s impossible but incorporating a trippy high into a LL program would require mucho work.
Depending on goals, I’d watch for trigger hours… ie how many hours of darkness a line/plant needs to initiate flowering.
I wouldn’t go as far as saying they are linked but surely with enough pressure they tend to follow one another.
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Over the years I have found that some plants produce better quality smoke when they are grown in “dappled sunshine”. The kind you get when growing back under the surrounding trees. Not much yield but definately better for your head.
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I have a setup where sometimes my plants grow above the lights and thus get no light at the tops. They develop buds just fine.
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I received an interesting info from users around the web which I would like to share.
As mentioned there are different strains but Mandala Seeds developped this chart.
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Thanks Mithridate,
Any specific strain defeated better logic:) ?
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