Deficiency in Plants!?

Question

Why does Nitrogen and Magnesium cause these deficiency in plants?

N & Mg both make the plant have yellowish edges around the leaves.

Answer 1

Leaf turning yellow with out outward reason such as lack of sufficient light means there is something wrong in chlorophyll formation .

Chlorophyll is green pgment vital for photosynthesis .

Now let us take a look at that pigment =

Molecular formulas of   the five  types of chlorophyll==

1) Chlorophyll a =C55  H72  O5  N4  Mg

2 ) Chlorophyll b =   C55  H70  O6  N4  Mg

3 ) Chlorophyll c1 = C35  H30  O5  N4  Mg

4 )  Chlorophyll c2 = C35  H28  O5  N4 Mg

and

  

5 ) Chlorophyll d  =C54  H70  O6  N4  Mg

The molecular structure of each one of them tells us two things =

A ) Chlorophyll is basically a protein with inseparable C H O  AND N   !!

So nitrogen ( N ) deficiency will hinder chlorophyll formation .

B ) Magnesium is also essential to make that protein CHLOROPHYLL  .

Therefore  Deficiency of Mg will not make that molecule in adequate quantity .



Finally , click on the links below to see the structural formula of it to see how a key position is occupied by Mg .

http://fig.cox.miami.edu/Faculty/Dana/ch...

http://fig.cox.miami.edu/~cmallery/255/2...

http://www.hsv.k12.al.us/schools/middle/...

http://www.benbest.com/nutrceut/chloroph...

From = A Botanist

Answer 2

Deficiency of plant nutrients cause blocks in metabolism. N and Mg are part of chlorophyll. Yellowing due to N deficiency starts in old leaves where as defeciency of immobile elements cause yellowing in old leaves. Nutrients are distributed in leaves due to venation and leaf edges are first affetced in N defeciency.Deficiency of Zinc causes varigated yellowing along veins.