Allelochemicals, roots and competition
> From: Stephen.Pushak at saudan_HAC.COM
> Date: Thu, 21 Sep 95 18:03:25 PDT
> Subject: Re: Allelochemicals, roots and competition
> Yet A. mad. will
> continue to show very slow growth even with trimming back the
I'm not at all sure that what you are seeing in this case is
> Some even suggested that Crypts and this Aponogeton
> had an affinity; increased oxygenation due to the roots of the
Although it is possible that increased oxygenation (or
circulation) is beneficial to A. mad.,(it certainly seems to be to
other rooted plants) it seems unlikely that this is a Cryptocoryne
specific phenomenon. They don't even come from the same
continent, so this would be a strange adaptation, indeed. ;-)
> For the Madagascar Lace plant we've got to focus on that individ
> since its demands seem so exact and unfortunately, unknown.
I agree with you completely here. In fact, I have read several
reports of success where the plants were kept either as a single
specimen, completely by itself, or else in a monoculture.
> John Madesen wrote:
> > I am replying to the comment about rooted plants outcompeting
> > for nutrients. Scientifically, there is no good basis for thi
> > if you mean nutrients in the water. Research has shown that r
> > plants take most of their required nitrogen and phosphorus fro
> > sediment, not the water.
> This is very fascinating indeed. Perhaps all of our supplementat
> should be done within the substrate. It also corroborates the
> theory that iron-oxide in laterite is useful for fixing phosphat
> in the substrate. It makes me wonder more about the value of a
> slow RUGF system with an iron-oxide, high CEC substrate. Maybe
> it is a case of serendipity that a particular tropical or subtro
> location may support this Aponogeton and one should take soil
> samples and observations there to attempt to duplicate this.
John's comments may be correct as far as they go, but dismiss the
fact that _many_ of the plants we use in the aquarium are
(completely or in part) _not_ root feeders, and their needs must
be met as well.
Aquatic Gardeners Assoc.