Dandaweedman

Iron
Iron is a vital element for plant and animal life. Iron has a number of important functions in the overall metabolism of the plant and is essential
for the synthesis of chlorophyll.
In general, iron is poorly absorbed by the plant.
It can only be sufficiently taken up by the roots in certain forms and under proper conditions.
Soil seldom contains too little iron, but it is possible that forms of iron that can be absorbed by the plant are lacking.
The absorbency of iron is strongly dependent on the pH.
Ordinarily there is sufficient iron present in absorbable form in acidic soils.

Marijuana is very efficient with the absorption of iron, and under normal conditions, it has little trouble with iron deficiencies.
Except during periods of heavy growth, or high plant stress, iron deficiency symptoms can temporarily appear that eventually go away by themselves. These symptoms are not detrimental to the yield.
An iron deficiency is characterised by a strong yellowing of the young leaves and the growth shoots between the veins.
This occurs chiefly because iron is not mobile in the plant.
The young leaves can’t draw any iron from the older leaves.
With a serious iron shortage, the older leaves and the smaller veins in the leaf can also turn yellow.

- Green/yellow chlorosis, from inside to the outside in the younger leaves
and in the growth shoots.
The veins remain mostly green.
- Continued yellowing of the leaves to sometimes almost white.
Also, large leaves turn yellow.
This inhibits growth.
- In serious cases the leaves show necrosis, and the plant’s growth and
flowering are inhibited.

Possible cause can include:
- The pH in the root environment is too high (pH> 6,5).
- The root environment contains a lot of zinc and/or manganese.
- The concentration of iron is too low in the root environment.
- The root temperature is low.
- The root medium is too wet, causing the oxygen supply in the roots to
stagnate.
- The root system functions inefficiently due to damaged, infected or dead
roots.
- There is too much light on the nutrition tank; light promotes the growth of
algae. Algae also use up the iron and break down iron chelates.

What can you do?
Light iron deficiency symptoms are rather easily reversible.
Depending on the origin, a shortage can be corrected by various means.
The pH can be lowered, excessive manganese or zinc fertilisation can be avoided.
Iron chelates can be added to the substrate, drainage can be improved or the ground temperature can be increased.
If a good fertiliser is used with hydroponic growing, an iron deficiency is almost out of the question.
A fertiliser with a good composition contains sufficient iron in a form that the plant can absorb.
A high iron content in the soil does not damage the plant, but it interferes with the uptake of phosphorous.

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