Rusts a follow up note

Paul Christian paul at RAREPLANTS.CO.UK
Sun Aug 10 20:08:16 CEST 1997


I stand corrected, but thanks Scott.

Any opinions on the fungicide cocktail, I didn't imagine the result but did
I imagine the caue of the 'cure'

At 13:43 09/08/97 -0700, you wrote:
>Greetings All,
>Just a few comments following Paul Christian's comments on Rust.
>Yes, rusts are usually quite host specific.  This specificity may be at the
>generic or species level, though many cultivars or natural ecotypes may
>have some level of tolerance, resistance or immunity.  However the rust
>fungi mutate readily forming many strains.  This provides workers in the
>Wheat Rust Resistance Breeding programs in the US with job security.
>Rust are extremely complicated as a group.  Some having as many as five
>spore types infecting two different hosts (heteroecious types).  While
>others (autoecious) have two to five spores on one host or only one known
>spore type and a single host.
>Arisaema rust is caused by Uromyces caladii which has 4 of the spore stages
>and has been reported from NY to FL and TX and the Pacific Northwest.
>(from the 5th ed. of Westcott's Plant Disease Handbook)
>I do not know if there is an alternate host or not. Perhaps some plant
>pathologist on the list or on Aroid-L might volunteer more information.
>A word of caution. Rust spores are windborne, thus very small and
>lightweight.  It has been reported in some species that the spores can
>cling to tools, clothing, (hair?) so  those who tromp though infested areas
>might not want to come home to their collections and go grubbing about
>As we bring more and more species together within the range of the pathogen
>it may just be a matter of time before strains appear that may cause
>serious problems.
>Sorry for the gloomy outlook...we pathologist types tend to have a wet
>blanket side to us.
>Best Regards,
>Scott Gregory Vergara
>Botanical Resources
>(Specialty Nursery, Horticulture Education/Training, Consulting)
>P.O. Box 669
>Burley, Washington  98322-0669   USA
>svergara at     HORTULANUS at
>USDA Zone 8 Ave Min Temp 10-20 deg F. Record low 0/hi 104
Paul :-))

Paul Christian   - Rare Plants
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