Re: Germinating Fall Pod TB Seeds


> > I failed to mention in my previous posting that I did stratify the
> > seeds.  They still will not germinate by doing this.  Out of about 20
> > fall crosses I got about 6 seedlings...total.  Holding pots over this
> > winter and hopefully I will get some more germination this spring.
> > 
> > Rick Tasco

There is a really interesting (oldish) Yearbook of Agriculture "Seeds"
that discusses in detail all the peculiarities of dormancies in seeds. 
One chapter is devoted to "After ripening, rest period, and dormancy". 
It contains such helpful and profound gems as "...man has tended to
select seeds that give relatively prompt germination" and goes on to say
that (at least in 1961 when this was published) some blocks to
germination are well known and others are complex and almost completely
unknown.

A possibly relevant idea I found in this chapter is the following:
"Mere drying for a period induces changes that permit germination in
some seeds.  This is afterripening in the dry condition..."  

Also, seeds may have "secondary dormancy" induced by high temperature
after afterripening (cold stratification in the 'fridge).

Embryo blocks may or may not be caused by the presence of
growth-inhibiting chemicals; "They may result equally from a deficiency
of some essential compound.  The effect of afterrippening might then be
to permit the accumulation of the missing compound.."

Since we are warned not to plant iris seeds outdoors in the fall because
they might germinate too soon and be winter killed as tender babies, it
seems they probably don't need cold stratification to germinate, but
might be inhibited by high (higher than fall?) temperatures during which
time the embryo does whatever it needs to finish doing before the seed
germinates.

Sooo, maybe the trick would be to put the fall seeds somewhere in a
dish, on a paper towel, or whatever you do with the spring seeds to dry
for a couple of months at a 'high' (room) temperature, then cold
stratify them.

What does Lloyd Zurbrigg say?  Surely he has figured out how to get fall
seeds to germinate.

Linda Mann east Tennessee USA



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