On 12/22/2009 11:03 AM, Frank wrote:
Sunleaves are the large leaves at the base of and associated
with secondary branches.

I assume their role is to feed the secondaries with products
of photosynthesis and release of stored mobile nutrients such
as N, P, K.

That being understood, what is the effect of pruning out
one or the other, as when making a plant into a bonsai?
If we're trying to arrest stem elongation by pinching back,
does it leave the plant stronger to remove just the tip in
question without removing the sunleaves?

I don't think "sunleaves" are any different from other leaves. They are
larger primarily because they are on branches that are sufficiently
mature to sprout side branches. When the side branches mature, they too
will have larger leaves. All leaves participate in photosynthesis once
they have opened up from their buds.

Leaves -- even the larger leaves on mature stems -- do not usually store
or release N, P, and K. Leaves use those nutrients to produce sugars.
Only fleshy leaves (e.g., on succulents) might store any nutrients other
than sugar.

--
David E. Ross
Climate: California Mediterranean
Sunset Zone: 21 -- interior Santa Monica Mountains with some ocean
influence (USDA 10a, very close to Sunset Zone 19)
Gardening diary at http://www.rossde.com/garden/diary