Hello all. As some of you are aware, I am growing a bunch of Black Pines from seed.
After the usual hot soak for 24hours and 3 month cold stratification in the fridge, they sprouted. It's been seven months now.
Some of them were cut as soon as the stem turned to red, and the taproot was trashed.
The results are somewhat baffling, not expected at all.
The ones supposed to be the strongest are the smallest.
From left to right, the first one was left in dappled sun, protected from heavy summer rains. Its a future double trunk and it is the biggest of the three examples.
The middle one was left in full sun and full rain, and it is the smallest of the bunch, but the stem looks harder, woody. Same color as the first one.
The third one on the right side was cut (tap root) and left in the same conditions as the double trunk; the color is way lighter but it has needles all over, very low on the stem.
I can't explain the differences, does anyone could help?

One of my books from long ago said that trees are trying to grow toward the sun. Give the tree full sun and it will grow slowly because it has what it wants. Full sun means it doesn't need much chlorophyll while shade means it needs more leaves and more chlorophyll so they get greener.

This may be true and it may explain. Sometimes I think these explanations are too simple, but it seems to make sense.

hey Ivan, thanks!
It makes sense. The deciduous in full sun always have smaller leaves. So it can happen with conifers also.
Interesting.
I thought the rain (being wet most of the time) could play a role in the behaviour of the seedlings left in full sun/rain.
Let's see if others can chime in and give us new possibilities.

Another view of the short one, growing in full sun/rain.

If it is correct, then it also explains why in the week I was in Canada everything was much darker green than here in Alabama. Grass and pine needles here are light green, maybe some yellow thrown in and there everything is dark green. Plants here don't need to do much to get enough sunshine.