Re: CULT: leaf spot

Well, Char, sort of <g>

As I described in the post about weather woes, I see leaf spot related
to freeze damage. I also see massive leaf spot consistently on certain
cultivars (and on certain seedlings of my own).  Little or no leaf spot
so far in the ridgetop clay garden.  No leaf spot in the grass infested
beds (also very little iris bloom!).  Varying amounts of leaf spot in
the rows with varying amounts and species of weeds/companion plants.
Definitely affected by weather - more in rainy and hot humid weather.
Probably affected by nutrition - worse with more nitrogen, I suspect.

I thought there might be a relationship between the amount of leaf spot
and aphid damage.  And generally, I suspect it's worse when plants are
stressed, as in high humidity, heat and drought on my gravel soil.

I am trying to select for cultivars that thrive without 'cleaning' and
in mixed beds, so the large majority of cultivars I am currently growing
are pretty tolerant of weeds and lack of air circulation around the base
of the plant.  Today, I noticed one cultivar that has yellowed up and
seems to have a major attack of leaf spot and suspect it is also
rotting, but haven't inspected it closely in this cold drizzling rain.
It has had some rot problems in the past, so may be on its way to the
afterlife.

I don't distinguish between bacterial and fungal leaf spot - don't treat
for either, plants just have to do the best they can here.

How's that for a wishy washy answer?

<Do you really believe this?  I had a lot of weeds last year due to
working
                   full time.  Also, no companion plants to speak of.
And I had leaf spot.

                   The year before, I had very few weeds, I was
unemployed and many companion
                   plants.  No leaf spot.

                   Char Holte, New Berlin, WI (Near Milwaukee)>
--
Linda Mann east Tennessee USA zone 7/8
East Tennessee Iris Society <http://www.korrnet.org/etis>
American Iris Society web site <http://www.irises.org>
talk archives: <http://www.hort.net/lists/iris-talk/>
photos archives: <http://www.hort.net/lists/iris-photos/>
online R&I <http://www.irisregister.com>

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