In message
"Charlie Pridham" wrote:


"Michael Bell" wrote in message
. uk...
In message
Michael Bell wrote:

In message
"David WE Roberts" wrote:


"Michael Bell" wrote in message
. uk...
snip
The scion and stock are 2 -3 mm in diameter, somebody on this group
advised me to use Hellermann sleeves (thank you for that!) to hold the
scion and stock together, it took some trail and error develop a
technique, but I can now produce a workmanlike-looking graft. I cover
the scion with lay-flat tubing and droplets of water, appear on the
inside of the tubing, obviously evaporation from the scion's bud and
leaves. So obviously water is being transferred, but the graft dies
after a few weeks. Why?
snip

Just wondering how long grafts stored under the same circumstances (i.e.
in
the tubing) last before they die.
Cut pieces of branches continue to grow and transpire.
If their cut bases are put into water they can last a good few weeks
before
they die.
So possibly all that is happening is that the grafts are behaving much
as a
pruning in a low water loss environment would.
Which would mean that they are not starting to take then failing, but
not
taking at all.
However, not sure how this helps you in your task.

I don't believe it, but it's possible. I can check it. I will put cut
scions in lay-flat tubing *not* grafted to the stock and see what
happens.

Michael Bell

Yes, you are right. "Scions" in lay-flat tubing with their cut ends
taped to stop evaporation do produce droplets of water on the inside
of the tubing in exactly the same way as the "grafted" ones. So, that
water is simply them evaporating the water that was in them. It
deceived more experienced men than me!

What follows on from this? What is the right degree of protection from
evaporation? Might it be that some water loss from the scion is
necessary to make the cells grow to join up the stock and scion?

Michael Bell

I have never done a lot of grafting of trees but I thought mostly it was
done while plants were dormant, however I notice that with some trees late
summer is also a possibility, but in all cases its in a closed case with
high humidity to prevent loss of water from the material


It seem that alders are grafted using "hot pipe" methods. That is to
say, you have potted alder stocks, you graft the scion onto them and
lay them across a heated pipe (such as you often go in old-style
greenhouses) and that provides the heat that allows them to grow.

That's not suitable for me, I want to graft onto rooted-in-the-ground
"adult" trees. I have found that if I bind to the graft with tape a
2.2 kOhm resistor (electronic components come in a logarithmic series
of values, and if you ask for "a 2kOhm resistor", they will give you a
2.2kOhm one) and feed it with 24 volts from a transformer, the heat
output is 0.28 watts and wrapped with 10 cms of bubble wrap (just
under 3 turns) the temperature stablises at 10°C above ambient - that
seems just right! So this morning I did some grafts like that and I
wait to see what happens.

But heat? What does it do? It promotes cell division and growth! Just
what you want for grafting. The notorious weedkiller 2 4 diCholoro
Phenoxy acetic acid does that too. Another possibility! I looked round
my local garden centre but their weedkillers all had glyphosate in
them, not what I want. I should be able to find some 24D somewhere,
but any ideas about whether it's likely to work, concentrations, that
kind of thing?

Michael Bell


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