"caparazon" wrote in message
news:1108843683.6474e930112b4bb17700f3b24d6bd27c@t eranews...

1) What makes that just the last buds, or just the last opened flowers
on flower twig fade and die, while others below are apparently keeping
health?. (Seen on my Odontoglosum and aldo on Cymbidium.)

Not knowing your growing conditions, I'll try to answer your questions.

Two things come to mind. Transient changes in the environment, such as
standing in a draft, changes (usually a decrease) in ambient humidity, or a
rise in temperature. Also changing the plant's environment, like bringing
it in the house from the greenhouse or outside. The developing buds will
'blast' and the more developed ones will remain fresh.



2) Whay makes that just the keikis, and not the rest of the plant, show
a quick dacay on their leaves, going quickly from normal green leaves to
yellow and then fall?: (seen on a my Dendrobium and on my oncidium).



I think its part of the same thing. The keiki out in the air doesn't have
the same support that the mother plant has (from its roots being in some
sort of medium that gives the plant water and humidity , as well as the
resource of water stored in back bulbs that can be pulled when needed to get
it over these fluctuations that occur in its environment) They dry and fall
off.

K Barrett