Question about Barry's book

[kby]

Barry,
I have a question for your about the culture descriptions in the book, in particular wrt the "light" parameter: Which is brighter: "intense light", "full sun", or "direct light" (and other terms that might similarly be ambiguous). I'm not trying to nitpick and figure out how many candles/ft² or something like that, although maybe a qualitative description might be useful (i.e. "intense" is a lot/little/slightly more than "direct").-kby

[BarryRice]

Hey Kby,

Good question. I hadn't really thought about ranking these terms until reading your posting. Let me clarify what I think about these terms.

Full sun---I think of this as unimpeded sunlight. No overhanging trees, no shade. The source of the illumination is natural sunlight. The sun's trajectory in the sky would put it, at highest point, at least 45 degrees from the horizon (which would be impossible for summer growers at latitudes in excess of +-68 degrees. Furthermore, the sunlight would be essentially uninterrupted for the entire day.

Direct light---This is essentially the same as full sun, but it can carry the connotation of being filtered a little perhaps by a window pane. Also, it might not be for all day.

Intense light---It could be full sun, but it could also be extremely high levels of illumination from artificial sources. Probably, "intense light" can be lower than "full sun" in radiant intensity.

I hope this helps some! Sorry about the slippery nomenclature; light is not easy to quantify since it is multidimensional---there is duration, overall intensity, but also the spectral composition. Only duration is easily measurable!

Barry

[kby]

Thank you Barry; that does help a lot.

I realize light is a complex topic, but I guess partly I didn't expect spectral composition to enter into a discussion about needs between species; mostly I didn't think we really understood those kind of differences. This I see as separate from an overall discussion of spectral compostion which you did a good concise job on in the overall discussion of light.

FWIW, other than filtration effects on spectral composition,
I figured the the main issue in the absence of other factors (mostly temperature) getting as close to sunlight in quality was the goal for any CP (follwing the Golden Rules), and the main difference was the quantity (duration and/or amount of shading needed, although I had not really thought of duration directly in terms of light—more of a dormancy related issue).

Anyway, that's how I read it; just so you have an idea of how at least one person interpreted what you wrote. No complaints; I just needed some clarification, so, again, thanks!-kby