Fertilizing and disease control on Hippeastrum
Hans-Werner Hammen (Thu, 27 Oct 2005 17:56:09 PDT)

Hi Roger;

it sounded really unbelievable to me and I first confirmed the term to be
indeed identical with the German "Urzeugung" meaning that little critters
are dirt-born.
Well I appreciate (in this very case) that my message gaves space to you for
such a wild speculation -
where, did you say, was my message keeping this information?

Nevertheless, the facts relativate, what could at first sight be regarded as
joke:

I experienced practically the entire bulb material I purchased from the
Nederland's sources to be infected with the tarsonemid mite.
This animal is able to spread very easily in an amaryllogene plant
collection.
It has to be regarded in its spreading behaviour - close - or better
apparently related - to microorganisms.
I read that sciarid flies can transport several mites.
To say nothing of a possible transportation by a windstream - a ventilator
wind stream, for example.
I assume that many infection occur by contaminated soil and contaminated
hands.

I lost an entire hippeastrum collection when I was 19 y old- due to the fact
that I did NOT know about these things I have *ggg* the honor to generously
inform you of.

I am in fulll concordance with Veronica Read (Hippeastrum - The Gardener's
Amaryllis)
about the significance and the relevant properties of the tarsonemid mite.

Lucky those people who never have faced any problems with this disastrous
animal.
On the GardenWebBulbForum there where many cases of postulated "red blotch"
but all image material provided so far revealed clearly that the mite was
the deeper reason for plant disease observed.

I do not know why some collections are not bothered by mites.
Although I do not believe that these are fully uncontaminated

For my part, I always experience a high infection pressure, from mites which
(want to) emerge from the substrate upwards into the bulb scales; and
therefore I have to spray the substrate surface and the bulb surface
thoroughly and regularly in order to avoid serious damage.

And as essential message I repeat:
It is an important difference;
To worry about red blotch -
or to worry about the tarsonemid mite.
I have decided to worry about the latter, or better to concentrate my
efforts on the fight against the true reason of the most important
hippeastrum disease.

Certainly I cannot afford to set the wrong priorities - as I have just begun
to introduce H.papilio germplasm from my regenerated 4ploid hybrid obtained
from H.papilio x "Donau" - into other, bigger blooming tetraploid
hippeastrums, the first being "Susan" as mother plant - the first time that
this wonderfull big pink did not refuse seed formation at all!

Hans-Werner