> I really doubt this would help at all. Nepenthes have strong
>apical dominance and this in itself would probably have ill effects
>on any grafts......after going through this trouble and flowering the
>plant, there is no way to tell if the new opposite sexed branch would
>even flower. Most Nep of flowering size, will have several ground
>rosettes and other vines (adult or usually not) and only one of these
>tends to flower at any given time.
What I observed with my N.khasiana (which was the one that grew
and flowered best for me in Brazil) was that during the
first few years of life, they had strong apical dominance on a single
branch, but once they got older and with a more developed rootstock, each
plant would have a few robust branches which would all flower at the same
time. I don't know, maybe this is because I had plenty of space at the
university greenhouse to let these plants grow while you guys have to
reduce spaces due to heating costs during your long and cold wihters
(which my plants never had to endure in Sao Paulo).
>Since they flower at the same this of year (if not the species would
>soon die out or need to flower all year long) I'd assume they are
>induced to flower by the same factors. Also, if it was hormonal
>factors inducing the sex, then plants would probably be able to
>change their sex but I have not heard of this yet.
Maybe because of your well-defined seasons you were able to
observe a flowering season for Neps, but where I used to live (Sao Paulo,
Brazil) the seasons were not very clear and I never noticed any flowering
season for Neps. I imagine that in their native habitats the only seasons
they know are wet and dry. Ive never heard that Neps have specific
flowering seasons. Do they???
>Here's a little secret for you all: It takes quite a few growth points
>and they need to be in the adult stage for this but it works very well.
>Take cuttings with about four or more leaves to them from two opposite
>sexed plants. At least 75% of these will flower within three to five
>months of being cut. Works like a clock (must be something hormonal)!
>You would have good chances by taking two cuttings from each plant and
>almost be guaranteed success with three from each. I would be producing
>seed this way if I had the room to grow good sized adult pairs from
>which to take these cuttings. BTW, this can also be used to sex your
>plants.
Sorry, but again this must be something about your growing
conditions. I never observed this with my cuttings. This is one reason
why I really didn't pay much attention to other people's growing tips.
There are just so many factors involved and often what works for one
doesn't for another. Especially in my case, since most of the tips I'd
get or read about in CPN were given by people in temperate countries,
where the conditions were very different from the ones in my hometown of
Sao Paulo.
>Fernando, with regards to what you mentioned, we once had a male come
>female Nepenthes rafflesiana in our garden in Malaysia. Male and
>female spikes were never produced at the same time, but I believe that
>this is due to the fact that a single Nepenthes plant GENERALLY only
>produces one scape per plant per season even when it is multiple
>crowned. Nevertheless, it's possible and may be a successful means of
>producing seed if you are lucky enough to get two inflorescences at the
>same time.
> A graft will not change sex - although it 'fuses' to the stock
> plant, it
>and its apical tip are probably genetically different and cannot change
>in the way you suggest to the best of my knowledge.
1st of all, Alastair, as in all organisms where the sexes are
separated (including us humans), there are often errors where both sexes
may be present and even functional on the same individual. I remember
reading in CPN a few years ago about a Nep which produced a flower spike
with both male and female flowers, or something like that.
As to each plant having only one flower spike, it was first
mentioned for a temperate country, but now your comment comes from a
tropical country (Malaysia) which is home to Neps. Maybe my N.khasiana
were abnormal or maybe it's just this species which produces flower spikes
on all of it's main branches. I don't know, anyone else observe multiple
flower spikes per plant with frequency??
As to grafts changing sex or not, again this would depend on how
sex is controlled in these plants. Chromossomes or hormones??
Fernando Rivadavia
Tokyo, Japan