Re: Leaf spot, Gene, Culture, Location....
- To: Multiple recipients of list <email@example.com>
- Subject: Re: Leaf spot, Gene, Culture, Location....
- From: firstname.lastname@example.org (L.Zurbrigg)
- Date: Sun, 8 Feb 1998 20:23:49 -0700 (MST)
>I am Edmundas from Lithuania. It's about 300 km farther than Sweden to =
>Ost.The problem with leaf spot for us are the same. We often have humid =
>summers and abundant rains. This disease is result of infection by =
>parasitic fungi from Genus Heterosporium. We call this disease =
>Heterosporiosis. The same disease can be affected by bacterium from =
>Here in Lithhuania we have wonderful pine forests with lot of maschrooms =
>in humid summer and autumn periods. It's no wonder, that those fungi =
>also like humid weather.=20
>Most I also remove affected leaves by cuting, in early periods only =
>above part. But you must know, that except humidity luck of phosphorus =
>and lime in the soil increase danger of disease. Of course, as all =
>living being, irises also have different resistance for this disease, so =
>one can find plants more or less resistant. Beardless irises are quite =
>resistant as it grow in humid areas and are adopted to that conditions.
>Good results can be achieved I think if spray plants at right time with =
>fungicides. What time is right? If rainy time is not long the best is =
>after rain. If humid period so far long some times to spray is well. But =
>fungi grow only in warm humidity. If humid period is cool there is no =
>need to spray. Here is explanation why irises are more healthy grown in =
>shade. There is cool, instead sunny place and fungi do not grow.
>Are somebody feel virus is set to this list? I had problems to write =
>this message, but earlier I had no such a crazy things with jumping =
>cursor all around interface.
Dear Edmundas: Thank you for your notes on iris culture there. Mosst of
our American introductions in bearded iris come from somewhat arid
climates. I am well aware as I write that California is anything but arid
at the moment! But summers are usually quite dry in the parts of the West
Coast where bearded irises are grown. Therefore introductions from such
locations , esp. in California, seldom would have a chance to show if they
are resistant to leaf spot. Only when they come East, and have to live
through hot and sometimes very wet weather, do they get the chance to show
the resistance to leaf spot that is desirable. As you state, soil
conditions also play a part, as does culture. But the bearded irises badly
need an upgrading in regard to producing good summer foliage here in the
Eastern United States. Lloyd Zurbrigg in Durham NC USA