rot and borer resistance, myth?

Nell said:
Sobering news.  There are not bearded cultivars that are strongly rot and borer
resistant? I'm willing to go back completely to pre-1950s varieties if need be.
If this search is fruitless for a large swath of the U.S., then be prepared for
AIS membership to drop significantly in the coming years.  Reluctance to use
garden chemicals in on the rise, more and more of them are being removed from
the market, and beautiful "new" perennials of all kinds that don't require them
are flooding into nursery commerce.
**
me here
**
No, I agree that many of the old varieties that have lasted all these years,
as well as some of the new ones, are much less susceptible to rot than some
of the others.  (I wish we were better at sorting out that characteristic in
the newer ones.)  To the extent that rot encourages borers, these are
borer resistant too.  I don't think that there is any TB, though, that
is immune to unprovoked borer attacks; it would be quite a valuable one.


Nell quoted me:
  >> the AIS standards are our best hope for maintaining perspective.  One
  >> could argue that the casual grower's interaction with catalogs that
  >> stress pretty flowers alone is where the perspective isn't present.
  >> Those who take the time to learn and appreciate the full set of
  >> criteria that the society urges are the ones who will end up
  >> recommending plants closer to your ideals.

And she said:
Wish I could believe that, but so many of the AIS standards are moving targets
having to do with bloom form (size, wide and flaring falls, ruffling, closed
standards, etc.) which are of virtually no importance to me compared with
garden toughness.  Even substance, branching, and bud count are values I'm
willing to sacrifice to some extent for a plant that will perform reliably.
**
me here
**
>From the _Handbook_:
"The ultimate objective for the judge is to seek and cast votes
for those varieties of exceptional quality that will consistently
perform for consecutive seasons with little pampering."
It agrees with us!

Nell also said:
Re the casual growers: These would be people who get their bearded iris not
from iris specialists, but general garden catalogs?  The TB selections of some
of the largest U.S. perennial merchandisers,  Wayside and White Flower Farm,
consist largely of fairly recent Dykes and other AIS award winners. Are these
indeed the iris to be 'pushing' to the general gardeer, or are there other
cultivars with less perfection of appearance but stronger constitutions?
**
me here
**
I included some of those who buy casually from our favorite pretty catalogs
in my definition of "casual" too.  I agree, though, that the selections of
the big ones are not always the best.  Sometimes they choose AIS winners
and sometimes they don't.  They can win or lose by our standards both ways,
but I think by picking AIS winners they will win more often than if they
chose randomly among the ones that did not win.  I think we need to continue
pushing the award winners, and, if at all possible, do even better at
adhering to our standards in selecting them.

Looking at TBs for example, durability gets 15 points out of 100,
stalk strength 10, and other qualities not obvious from catalog
descriptions are also well rewarded.  I think AIS in its standard-setting
overall does pretty well.

Yes, there is a question of how well the body of judges follows those
standards.  Many times the results of the balloting have not matched what
I voted for, and clearly the others made mistakes.  (I'm not sure whether
I mean to have a smiley there or not, but there also has been more than once
where I later became convinced that my vote was wrong and properly outvoted.)
I do think, though, that the collective wisdom of the judges, while not
perfect, has some merit.  I sure would like to improve it, and I think doing
something about the TB time and number problem, as we discussed earlier, is
important.

Nell continues:
Perhaps my impression is wrong, but it has always seemed to me looking in at
the iris world from the outside, that there was a point in iris gardening
history when rot and borers were not such enormous problems.  Then they began
to be.  I can't pinpoint the period, but it seems to have been somewhere in the
late 40s and early 50s.

Reinforcing this idea for me was the difference in treatment of the topic of
pests and diseases in Sidney Mitchell's _Irises for Every Garden_ and a later
(early '60s?) book by Leslie Cave (British).  But what had the strongest impact
was probably R.W. Munson's introduction to _Hemerocallis: The Daylily_. It is
is an impassioned plea to daylily hybridizers not to let disease and insect
susceptibility creep further into the Hem. gene pool:
"We have seen breeders in other genera march heedlessly into the future --
  a future dimmed because they were indifferent and ther plant became too
  difficult to grow or too much of a 'nuisance'."

Munson's close association with Steve Moldovan leaves little doubt of the
identity of one of these "other genera".  Is Munson all wet here?  Did not the
the quest for ruffling, size, new colors and patterns, etc. lead iris
hybridizers to overlook infirmities?  (In other words, will I not be able to
find older cultivars that predate this terrible turn because it didn't really
happen that way?)
**
me here
**
I think this is a good question.  An alternative theory, of course, is that
it wasn't the irises that changed, but the overall prevalence of pests because
more people were growing irises.  Also, the current crop of new ones, yet to
be sorted out, is always going to have a lower average than the ones who
have survived a few years and not been discarded.  The old ones that prospered 
and stayed popular over the years are certainly the fittest of the bunch and 
have stood the test of time lots more than the ones that are fresh from the 
hybridizer and surprising us on the ballot.

I'm glad you are raising these points, and maybe the others can shed more
light on them.

                                        --Jim

--
Jim Wilson, Miami Valley Iris Society, SW Ohio, USA, Zone 6a, AIS garden judge
growing TBs, medians, SIBs, JIs, & a few SPU & species.   wilsonjh@muohio.edu
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