Hi! I've been reading this forum recently and just registered to ask a question. I have a very small variegated Schefflera and the small newest leaf is rather reddish. Could this be "sunburn" from receiving a lot more light than it was getting at the garden shop I bought it from? I've only had it about a week or so. My other little Scheffleras seem happy, I just put them in the tank recently because my new house is old, cold, & drafty.
Thanks, Laurie
Not sunburn (photo-oxidation).
If the leaves are showing red coloring that is not a natural part of the foliage pattern, it's from a build-up of the pigment anthocyanin. This often occurs when something causes growth to slow or sugar translocation is disrupted w/o affecting the plants photosynthesizing ability. A common reason is chill - growth slows while the plant is still able to carry on photosynthesis. For proof, look to early spring outdoor bed plantings. When you plant them before soils are warmer than 55* F., they often go purple as anthocyanin builds. A 'P' deficiency is another cause of red leaves - and there are a number of factors that can cause a P deficiency.
Sunburn, caused by high light intensity levels, causes chlorophyll molecules to rise to a more excited state than normal. If light levels are high enough, the energy that is released as electrons in molecules return to their normal energy state may be sufficient to form oxygen (O2) radicals from regular O2. These O2 radicals are extremely reactive particles that readily destroy chlorophyll molecules. (This is the same O- radical that causes rapid oxidation in organic molecules when we apply H2O2 [hydrogen peroxide]) - you know, the stuff you bleach hair with? Evidence of the process after high light levels is seen in a bleached, whitish, or silverish appearance of the affected leaves - not red.
Al
Thank you.
I was a little worried about it, but I hope it will be happier in the tank. I had had them upstairs in a south window, and it was pretty cold up there.
