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Re: Cryptocoryne affinis leaf drop
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To: Aquatic-Plants at actwin_com
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Subject: Re: Cryptocoryne affinis leaf drop
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From: Neil Frank <nfrank at nando_net>
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Date: Sat, 02 Mar 96 08:48:44 -0800
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Newsgroups: rec.aquaria
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References: <4glh3i$i68 at usenetz1_news.prodigy.com> <31332D3B.680C at ti_com> <mcnei002.825568483 at maroon_tc.umn.edu>
>From the description the leaves appear healthy, but abscise from the
>plant and float to the surface? Could the abscission be due to some
>physical action, such as a parasite chewing through the base of
>the leaf? Transfer of infected material from one aquarium to another would also
>transfer the organism of interest.
>Microscopic (even a hand lens might work) examination of the
>infected material might provide some insight to the source of the
>problem. If you don't have access to a microscope I could examine some of
>the infected material. I have an extra aquarium in my office that I had
>been planning to switch over from a Rift tank to a planted aquarium. I
>could bring some crypts (affinis and other species) from home, establish
>them and then add some of your contaminated material if initial
>observations prove unsuccessful.
>
>Ken McNeil
>Horticultural Science Department (612)624-2715
Ken,
Many aquatic plant enthusiasts would be eternally grateful if you can
figure out what causes the described problem with Cryptocoryne. This is
the so-called cryptocoryne disease that affects many (or all?)crypts, but
particularly the affinis species.All or part of the leaves appear to melt
over a period of several days. It has been hypothesized that the problem
is attributed to a virus and the University of Florida was even given a
grant by the Florida plant growers to try to isolate one. As far as I
know their results have been inconclusive to date. It has also been
suggested that a change in water chemistry can cause the melt down. This
is because a water change or introduction of fertilizer or other chemical
change can sometimes trigger it. Nitrate is often mentioned. The problem
can also happen when another crypt is added. I have experience all of the
above. The onset of the problem following addition of a new plant does
suggest allelochemicals, but could also relate to some other chemical
that comes from breakdown of the new plants leaf. The water conditions
may also be a factor, because hard water/soft water and concentration of
certain elements like copper can make a difference. One way to reduce the
chance of this occuring is to remove most of the leaves from new plants
introduced into a tank with crypts. This is a most perplexing problem.
Contact me if you have any new ideas.
Neil Frank