Sorry to say it looks like virus infection to me.
I had a lab test my Persian Padishah and it was positive
for Potyvirus. The yellow streaking on the leaves as
they emerge is a good indicator. I don't think many
growers on this side of the Atlantic know of this problem.
The specialist growers and plantsmen in Europe have more
knowledge of it. Some advised me of this after posting pics
on a forum I belong to. The virus can be spread by sucking
insects or even wind damage from leaves brushing together
and sap being transferred. In general I do not see it being
fatal, in fact some that show it actually grow and
increase well but may die in the future. The worst thing is it spreading to a collection of rare and special iris.
Lab testing cost $75.00 for 1 sample.
--- In firstname.lastname@example.org, sdayres2@... wrote:
> This is an arilbred. The iris foliage looks streaked. Otherwise it
> appears to be healthy. Is it low on iron or zinc? The other irises around it
> appear healthy.