[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Call for observations: Deficiency/toxicity symptoms

>From Pete and Kellie Schmidt <petes at nas_com>, Feb 5:

>I have been looking (unsuccessfully) for an article that lists target
>ranges, minimum / maximum concentrations for major / minor / trace elements
>and their deficiency / toxicity symptoms.
>I would like to compile as much information as I can on the topic, and "get
>it in the archives" at the Krib, APD and possibly TAG under an easy to find
>topic heading.
>The only "compiled"  info I have located on symptoms is in the Krib archive:
>I am hoping to elaborate on the table by including observations, comments
>and hopefully even pictures by fellow APD'ers
>I have several references for hydroponic (terrestrial plant) nutrient
>concentration max/mins and deficiency/toxicity symptoms, and I'm curious to
>observe the parallels with aquatic plants.
>SO... here's the request:
>1. If you have observed deficiency or toxicity symptoms or you have
>information on nutrient target, maximum or  minimum  concentrations,  Please
>send them to me (email) and I will compile and post the results.
>2. If you have pictures of symptomatic plants, I'll try to get them into the
>article as well.
>3. If someone has already done this, please let me know and I'll try to
>ensure that the information can be found (Advanced Newbie FAQ Deflector
>Shield comming on line <g>)

Steve Pushak, Dave Huebert, and I are members of the AGA Technical Advisory
Committee, headed by Diana Walstad. This is a provisional committee of the
Aquatic Gardener's Association.  The four of us have been talking along
similar lines, and we agree with you that there is a need for more pictures
of deficiency symptoms of various essential nutrients in aquatic plants and
also a need to establish recommended ranges of concentrations of nutrients
in aquarium water.  We have recently been working up a number of
experiments that we would like to see people do on substrates, nutrient
deficiencies, green water, etc.  We hope to have  descriptions of these
experiments published in one of the future editions of The Aquatic Gardener
with hopes that we can find people willing and able to do them.

In the meantime, anyone wanting to do anything along these lines does not
have to wait, but can contact Diana, myself, or Steve.  Be prepared to get
involved in a lot of discussion about how best to do the experiment.

I am the photo editor of TAG and would love to get any photos of deficiency
symptoms where it is pretty well known what the deficiency is; for example,
adding the element cured the symptoms.  Ideally, it would be nice to have
pictures of mild deficiency symptoms as well as severe deficiency symptoms.
Color slides would be best.  I would like to get, for AGA, a collection of
digitized images of deficiency symptoms that we could use in articles on
deficiencies and possibly post on the TAG web page.  If we could accomplish
this, it would be of great value to aquatic gardeners.

in a post to Dave Huebert I made an attempt to add to or modify the
deficiency symptoms in you saw in the Krib archive.  The modifications are
based on my own observations, and are by no means the last word:

Here are my changes:

Nitrogen-----------entire plant turns yellow green, and the older leaves become
                   more yellowish than the younger.  Older leaves do not die
                   unless deficiency is extreme (almost never seen in aquaria).

Phosphorus---------Plant stops growing and becomes darker green or stays green.
                   Some species may become purple with excess anthocyanin
                   pigments building up. Other species do not produce excess
                   anthocyanins and just stay green and small.

Calcium------------ (1) mild deficiency---Smaller, distorted new leaf growth.
                    Reduced leaf tissue, with the central vein persisting.
                    Leaves often cupped, rather than flat.   (2)moderate
                    deficiency---Often sudden bends or twisting of leaf, which
                    is now much reduced in size.  White streaks or white edges
                    in new growth.  Roots are stubby and twisted.  Root
tips may
                    die.   Leaves of Vallisneria are strongly crinkled as
                    they have tried to grow and got jammed in a small space.
                    (3) severe deficiency---New growth almost entirely white.
                    Leaves are tiny deformed stumps.  Growing points for both
                    shoot and root die.

Magnesium-----------In dicots---Yellowing of older leaves that starts from the
                    egdes inwards.  The midrib may remain green while the edges
                    are yellowed or whitish and dying (I don't know what this
                    deficiency looks like in monocots like Vallisneria, but it
                    should involve death of the older leaves. )

Potassium-----------Small dead areas appear in older leaves.  These can start
                    like little pinpoints and grow.  In some species, like
                    Ceratopteris, the older leaves stay green while the little
                    dead spots grow.  The new leaves are reduced in size and
                    leaf area, looking a bit 'singed'.  In other species the
                    older leaves can turn yellow before they die, but they do
                    not have green persisting along the major veins as in
                    magnesium deficiency.

Iron----------------Reduced chlorophyll in new growth.  Leaves and stem are
                    about the same shade.  Growing tips of Ceratophyllum become
                    pinkish and then white.  Eigeria densa tips become greenish
                    yellow to yellow with the leaves small and clasped close to
                    the stem.  The new leaves of swords are smaller with
                    or broad streaks extending lengthwise that are more pale
                    than the rest of the leaf (in mild deficiency).  In more
                    severe deficiency in most plants chlorophyll is lacking
                    completely in the new growth which soon dies.

Boron---------------Very similar to calcium deficiency.  New growth is
                    distorted and smaller, and then the growing tips of both
                    roots and shoots die.  In mild deficiency in Crypts, the
                    leaves are cupped and the roots are shorter and distorted.

Paul Krombholz, in soggy central Mississippi.