Posted by Gus on 11/13/2008, 11:42 pm, in reply to "Indoor growing" Link: Eucalyptologics: Info resources on Eucalyptus cultivation worldwide
83.45.72.114
Hello Alvar 
I think you should not worry about the walnut nuts.
And I think what you are seeing with different plant growth habits is a result of the amount of light and photoperiod.
Under lamps, when well placed, plants receive light quite homogeneously to all of their leaves. That might be the reason why all the buds (where cells are dividing to create new growth), all the ones at the end of each branchlet (terminal buds) and all the ones developing further lateral branches from the axil of each leaf (lateral buds) are similarly active. Light arrives "without effort" so the plants do not have to push growth upwards in reach of light, and grow "in all directions".
The ones near the window receive natural light, but with variable intensity along the day and none by night. So, not all the buds receive equal light, the plant pushes growth in height to try to get as many as possible of those buds under as much light as possible. If you bent them in the opposite direction from light and tied them to keep them away from the window, the new growth would bend back towards the window. Eucalyptus are quite phototropic, even if it is a slow movement compared to herbaceous plants!
And yes, results could vary a bit depending on the spectrum. But I think photoperiod ("length of the day", be it natural or artificial) and the direction the light comes from will tend to give more visible effects than the spectrum. Unless the lamps do not give any radiation in the violet-blue spectrum at all, in which case photosynthesis does not work well.
But in such a case, light demanding plants (as eucalypts are) would sooner or later show symptoms: clorophyl would be replaced by carotenoids, and the plants would change from green to orangeish or reddish.
Not an expert on this, my winters days are short, but enough for the plants to keep growing. So, just my ideas, not necessarily the truth
Message Thread:
« Back to thread