Re: hostas nematodes and etc.

In a message dated 7/27/2004 3:21:41 AM Central Standard Time, Meum71 writes:
If only a few plants are infected the plants can be removed and soaked in
Zero-Tol for 30 to 60 minutes at a 25 to one ratio with water. This will kill all
the nematoids with in the plants.

Zero-Tol is a non metallic and non organic pesticide commonly used to control
fungi and algae?  Being non-organic it is safe, except in its concentrated
form were it is a strong oxidizer and should thus be handled with caution to
keep it off ones skin and out of ones eyes. Once mixed up it is no more hazardous
than hydrogen peroxide.



This product can also be used to control populations with in the landscape
and soil, the normal recommendation is a 50 to 1 ratio mixed with water, but at
this rate it is not as effective. I have tried different amounts on different
plants and plants seem to, for the most part like being sprayed with Zero-tol.
 The mix that seems to work the best is one that is 30 to 1. ( one reason
that ferns have been implicated in spreading these nematodes -- is that ferns are
sensitive to many chemicals and were not treated that often, even when there
were more effective but toxic pesticides used to control Foliar nematodes).

 I have a test plot of Hosta that were at one time very much infested with
nematodes, The plants are Golden and Diamond Tiaras. Over the years I have
received plants from more than nine different sources that have had Foliar
nematodes.  Even received liners grown in a green house that were infected, I don't
buy any Hosta now that are called OS or originator Stock any more because of the
problem, and have also received 2 or 3 different Toadlily plants infected too
from different sources. Hosta seem to have the most problems because they are
a perfect environment for the nematodes to grow and reproduce, Hosta are
grown in the shade and have large thick leaves with lots of tissue that doesn't
die quickly after the initial infection, thus a number of generations can live
and reproduce before the leaves dry up.  In other plants the nematodes live but
do not build up populations as quickly and thus do not show symptoms until
very late in the year, which is more often excused as "normal" fall decline.

Back to the test plot of Hosta and the spraying, After two years of treatment
which included spraying 6 times from May into late July the plants show no
symptoms at all of infection, while in the past the entire plants would turn
brown and die off by late summer and the control plants are showing heavy
infections. One needs to spray so that the entire plant is soaking wet, both the tops
and bottoms and should be done on a cloudy day or in the evening so that the
solution has the maximum contact for the longest posable time with the plants,
I also soak the ground down well around the plants.

I believe that with good clean up and treatments of Zero-tol and maybe an
application of a fungicide with a "sticker" one can control satisfactory the
populations of Foliar nematodes on Hosta and other plants. Most likely this has
not yet completely eliminated all the nematodes with in the soil and reinfection
can occur.

There are thousands of different species of nematodes in the world some feed
on other nematodes and fungi and others live off of decaying matter and others
live on and in live plants and animals.  Its said that for ever human on the
plant there are thousands of insects, but for every one of those insects there
are tens of thousands of nematodes in the world.

The species of Foliar nematodes that are infecting our gardens do not like
heat and can be killed off if plants are moved into full sun for a season or
two.  Also it is helpful to use a thick layer of mulch to suppress the nematodes
movement from the ground to the plants, keep the foliage off the ground and do
not over crowd your plants.  Those plants with thicker cuticles tend to be
less prone to infection, since the nematodes cannot enter the leaves-except
threw wounds, while thin leaved plants that are low growing are infected the worst.
Throwing away infected plants does not mean elimination of the problem-but
one must also remove the ground around the plants and replace with clean soils,
city compost sites might be a source of spreading this pathogen if the compost
has not been heated to kill off the nematodes.
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