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"Paul M. Cook" wrote in message
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"Nelly Wensdow" wrote in message
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"Paul M. Cook" wrote in message
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Well the leaves continue to die at the crown although a couple very
deformed ones have managed to survive. What I discovered this morning
was the pot was crawling with tiny black flies. Must have been a
hundred or more. So I hosed it with pyretherin spray and that killed
them off quick. Could this damage be caused by a fly larvae?

Yes, fungus gnats. A thin layer of sand on the soil surface will
discourage flying adults from laying more eggs. Use some kind of Bt next
time you water (a dissolved mosquito dunk will work in a pinch) for
longer term control.

Turns out it was ZYMV - zucchini yellow mosaic virus. Took one of the
affected plants up to a good garden center with real gardeners running it
(not teenage kids) and the guy said it was mosaic virus. He advised
dumping the soil and scrubbing the container.

How serious is this? Is it totally contagious? Is it safe to reuse the
soil with some other non-cucurbit plant?

Google is your friend (well, except when they are spying on you):



The disease may be introduced in infected seed, so sourcing clean seed can
help prevent the disease. Control is largely dependent on using insecticides
to control the aphid vectors. A form of "inoculation" or cross protection
may also be used where seedlings are inoculated with a non-virulent strain
of the virus (ZYMV-WK); this prevents infection with the severe strain. and
so on.




Like all other aphid-transmitted viruses, ZYMV is extremely difficult to
control with insecticides, reflective mulches, and mineral oils. Better
results can be obtained with resistant cultivars.

Resistance has been found in lines of Cucumis sativus from China and in an
accession of C. melo from India. However, this resistance proved to be
strain-specific and is not effective against a second pathotype of the
virus.

Resistance is available in a wild squash (Cucurbita ecuadorensis) and in a
C. moschata line from Nigeria.

All commercial cultivars of Citrullus lanatus that have been tested are
susceptible, but resistance is available in some accessions of C.
colocynthis from Nigeria. A very high level of resistance was found in some
races of C. lanatus from Zimbabwe, but it confers resistance to the Florida
strain only.

In recent years, new squash lines possessing the coat protein gene of this
virus have been developed and proved to be resistant under field conditions.
The ZYMV coat protein gene has also been incorporated into melon and
cucumber.

Almost entertaining.
--
- Billy
"Fascism should more properly be called corporatism because it is the
merger of state and corporate power." - Benito Mussolini.
http://www.youtube.com/watch?v=Arn3lF5XSUg
http://www.thirdworldtraveler.com/Zinn/HZinn_page.html