Re: [tomato] More virus opinions

Thomas Giannou (Tomato@GlobalGarden.com)
Thu, 16 Dec 1999 07:39:38 -0800

Pete,

In your queries to extension offices and the like about your tomato plants,
did they mention anything like what would happen to a plant that was
infected by those virus diseases at a time just before flowers appeared?
Have you seen any info about how quickly the virus will act once the white
flies bring those diseases to your plants?

Also, is there any sort of life cycle or hatching cycle with the white flies
in your area?  or are they an insect that seems to always be around.  Are
there months where they are not present in Florida?  How long does a White
Fly have to be on a tomato plant before the virus transfers?  Do those
insects have to eat into the plant in order to transfer the viruses?

I am also wondering if mosquito netting or some fine mesh that will let
light and water through could be used to keep those insects off your tomato
plants.  I've been in the Orlando Florida area a few times and as I recall,
the afternoons are generally subjected to thunderstorms and a fair amount of
rain.  The netting and the frame holding the netting might be subject to
high winds from time to time during the hurricane season.  The design of
such covering might have to accommodate rolling up the netting and storing
it during times of high wind storms.

Do you have access to any tomato farmers to ask them how they are
controlling the White Flies?  I know the extension offices could probably
tell you about those details, but if there are any growers coops you could
go to and quiz, you might learn more about what sort of controls are most
effective.   You might want to seek out some organic farmers and see what
they are doing to control that sort of insect.  Every time I visit with
organic farmers, I always come away with some remedy they are using that the
extension agents don't know about.

Best Regards,
Thomas Giannou
Spokane, Washington




----- Original Message -----
From: Pete <Orchid@ispchannel.com>
To: Tomato Discussion Group <Tomato@GlobalGarden.com>
Sent: Thursday, December 16, 1999 7:09 AM
Subject: [tomato] More virus opinions


>
> I have examined your digital images for possible diagnosis of your plant
> problems.  Images 011-015 (all tomato) seem to exhibit symptoms of virus
> disease--very likely one or both of the geminiviruses vectored by
> whiteflies.  Both these viruses are very damaging to commercial production
> and urban gardening in Florida.  There is no curative measure that you can
> apply once a virus disease has occurred--except roguing the plants and
> destroying them.  The whiteflies carry the virus for their lifespan (25-30
> days).  The last image (eggplant) provided insufficient information to me
> to even make a guess.  I could not discern any clear symptoms.  Please
> understand that digital diagnosis is in it's infancy.  Plants can exhibit
> only a finite number of symptoms to an almost infinite number of plant
> pathogens, environmental, and cultural factors.  My diagnosis is an
> educated guess.  If you desire accuracy, the core laboratory of the
Florida
> Extension Plant Disease Clinic identifies the geminiviruses at the DNA
> level at a fee of $40.00.
> Gary W. Simone
>