On 24/08/2014 16:16, Spider wrote:

Are you sure about the change in light direction causing bud drop,
Spider? A quick bit of googling revealed quite a few hits mentioning
temperature and humidity as causes, but none mentioning light. I have 5
phals on a north-facing bathroom window, where they flower well, but as
they grow and flower into each other I often turn them 180° to avoid
this. I've never had a bud drop off.

Yes, I've read it in at least one of my many orchid books. I don't
think it's the same as bud blast. In the early days of my keeping
orchids, perfectly healthy buds would abort mysteriously relatively soon
after I'd got them home. Then I read about their dislike of movement,
obliging them to twist on the stem. Since then, I've taken particular
care when manoeuvering them and had no casualites, which would seem to
bear it out.

I'm wondering now, because of what you say, if this habit refers
especially to the smaller buds which appear to have no pedicel (which
would allow them to move), and that bigger buds with developed pedicel
are freer to move. Interesting.

Roger Tonkin's post seems to suggest that there is no problem turning
phals. Seems like some experimentation is required! If you have enough,
why not turn a couple and leave the rest alone, everything else staying
the same (heat, humidity, watering, etc)? It would be interesting to see
if those dropped their buds while the others didn't. If they did, the
question would then be why some experience bud drop on turning whilst
others don't. Curious.

--

Jeff