Iris winogradowii - elaisome?

totototo@telus.net totototo@telus.net
Sat, 10 Feb 2007 14:27:02 PST
On 9 Feb 07, at 9:53, Diane Whitehead wrote:

> I have seeds of Iris winogradowii from Dr Pilous.  I sowed half 
> immediately and soaked half for three days.  I am ready to sow the 
> soaked ones, but I notice that each brown seed has a pale blob 
> attached to one side.  What is this?  Is it an elaisome?  Do I need 
> to remove it?

Just leave them alone. It almost certainly makes no difference, but 
as a general rule the more you fiddle, the greater the chance of 
doing something wrong. If the seeds are fertile, they *want* to 
germinate. Just be prepared to wait five to ten years for flowers.

As for pre-soaking, I'd leave iris seed in water longer than three 
days to make sure they are fully hydrated to the core. A week, even 
two, would not be excessive. As long as you keep an eye on them, of 
course, and rinse them and change the water if it starts to go cloudy.

Those seeds you sowed dry? I'd rescue them, give them a good soak 
too, and then re-sow. A dry seed is a weak seed and a weak seed is 
more likely to rot.


One last tip: with seeds of rare plants like I. winogradowii, it's a 
very good idea to treat the seed pot with a good fungicide post 
sowing. Ron Pal, who used to run the now-defunct Mosswood Nursery 
here, once told me that giving all seed pots a dose of captan greatly 
improved germimation percentages.

The clear inference from this information is that soil-borne fungi 
are big enemies of seed. I don't think even using sterilized media 
works very well for seeds that take a long time to germinate; one 
spore from the air or the water and bingo! the mycelium will fill the 
pot in no time flat.

Regrettably, Captan has been taken off the market (afaik). I'm not 
sure of the exact reason; perhaps it caused children in the vicinity 
to grow horns or third eyes or something. But as matters stand there 
are few if any good fungicides now available to hobby gardeners and I 
cannot recommend anything else.


-- 
Rodger Whitlock
Victoria, British Columbia, Canada
Maritime Zone 8, a cool Mediterranean climate

on beautiful Vancouver Island


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