From: ramirez@julia.math.ucla.edu (Alice Ramirez)
Newsgroups: rec.gardens
Subject: cherimoya (custard apple) question answered+reflections
Date: 15 Oct 92 01:26:47 GMT
Organization: UCLA Mathematics Department

An answer to the poster's question about Annona cherimola, aka cherimoya,
custard apple...they sprout easily from seed.  Here in California
named varieties are available (grafted onto seedling rootstock) and
enthusiasts among friends in my beloved weird fruit group all have their
Bfavourites.  Cherimoya don't come true from seed any more than other fruit
species do, but hey, you may end up lucky.  if you don't have access to 
grafted named varieties it's worth a try.  They make a pleasant loooking
tree.  They get to be (the ones I've seen) about 20 feet tall max.
They are to be considered understory trees. That is, they don't like hot hot
direct sun (at least not in my area.  At least not in my garden where
they do worse under strong sun, and better in partial shade).  They are
very pleasant trees with largish, soft, somewhat velvety gray-ish green 
leaves. 

But there is one thing very important you have to know about cherimoya, and
this is the reason the fruits are so damn expensive in the markets.
The female part of the flower is receptive early in the morning.  The
male part sheds pollen late in the afternoon, after the stigma is no longer
receptive.  What is commonly done is to collect the pollen in the afternoon,
brushing it into some container, then going out in the morning and brushing
last nite's pollen onto the newly opened flowers (and you can tell newly open
from old.  The old are rather spread out and shriveled looking by late after-
noon, the fresh flowers are nice and green and the petals have not separated
very far from the center of the flower).  What I mean is, every flower
that is newly open should be brushed with pollen.

  If you are lucky, these
will "take" and you will start to grow cherimoyas.  The common belief among
the weird fruiters of california is that this species, which originated in
the fog forests of Equador, are able to pollenate spontaneously because
the fogs keep the female part viable long enough for the anthers to mature
and shed.  The basis for this belief is that cherimoya will often form
spontaneously (without need of hand-pollenation) along the coast, whereas
in the much drier inland areas (i.e. 5+ miles from the ocean) they will not
fruit unless hand-pollenated.
                            
I once experimented with gibberelic acid (sp?), brushing a diluted solution
of this onto the flower while still in its female stage.  I did a number
of flowers this way, treating them with the acid but not pollenating them, 
and was quite thrilled to see fruits form from these.  As time passed, the
fruits grew quite misshapen (I was willing to live with knobby weird fruits
so this in itself wasn't a tragedy), then when about 2 inches across, max, 
dropped off.  I was devastated.  I had hoped, and temporarily believed, that
I had solved a major agricultural fruit growing problem, one that would turn
cherimoya into a major California ag-biz industry. Would b urn my name into
the history of California fruit growing.... Sigh!!  (but then I've tried this
before. I was the one who thought sausage fruit might be another starch fruit,
ate a piece to see how it tasted, and hallucinated.  Another grandiose plan
bites the dust.

Oh well, better total obscurity than Death by Botany...I guess.