with
> dilute fish emulsion. I even sprayed an orchid that had some of those
black
> (fungal?) spots on the leaves with the dilute milk and it helped it.
Now that you bring it up....
Just before my Phalaenopsis began growing the stem (after almost a two year
pause), some areas on the leaves started developing 'those black' spots that
you speak of. They started small, at the edge of the leaf in a semi circle
and proceeded to spread almost towards the middle of the leaf, and than they
stopped on their own. I was concerned that I am loosing the orchid, and
then the stem began shooting up.
At the moment, the leaves are in a sorry state, but the stem is looking
great and seven flower buds are forming nicely.
Do any of you know what these spots are where they come from and are they
any reason for concern?
Raven
Spydergrl wrote:
Raven
The only orchid I am familiar with is Cymbidium, but my pot plant
"bible" mentions that Phalalaenopsis is very sensitive to water drops
lying on the leaves which can cause dark spots and sometimes lead to
rotting. If the trouble on your plant now seems to have stopped
spreading I should think there is nothing to worry about, but it would
pay to be careful about the humidity in future and wipe off any drips on
the leaves as quickly as possible..
For orchid growers in general, it is possible to apply fungicide for
leaf spots but a plant disease book of mine warns against using more
than absolutely essential on any orchids because of the danger of
destroying their internal mycorrhiza. It would obviously preclude the
use of any systemic fungicide on this group (but of course people on
this list are unlikely to make this mistake!!)*
One other _very_ occasional cause of leafspots on orchids is apparently
virus and if a plant is is regularly spotty and increasingly unthrifty
I suppose this _might_ be suspected. Unfortunately as I am sure most of
you already know, with most viruses the only control is the destruction
of the "patient".
*In case you don't already know, orchids typically have an internal
mycorrhiza not just in the roots but right through the plant body. As
far as I know they are unique among flowering plants in this feature. It
makes them a bit tricky to raise from seed, as without the approprite
inoculation with their correct companion they just don't grow.
Moira
--
Tony & Moira Ryan
Wainuiomata - at the Southern tip of North Island, NZ,
Lat 41??15'S, Long 174??58'E (Antipodes of Spain/Southern France)
