Transcript Nutrient Deficiencies

Nutrient deficiency symptoms
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Nitrogen
Phosphorus
Potassium
Magnesium
• Iron
• Manganese
• Molybdenum
Nitrogen deficiency is typically a yellowing of leaves particularly the older/lower ones as shown
top left; compare with healthy leaves bottom left. It can be confused with other deficiencies
e.g. magnesium deficiency (see bottom right) where the leaf shows a yellowing between the dark
green veins.
Phosphorus deficiency shows as a purple colouring of the leaf. Often the veins of
the leaf turn purple. In this example the purple colouring is central to the leaf. It
can often be confused as cold damage; but the damage is away from the margin of
the leaf.
Potassium deficiency typically appears as a marginal yellowing/browning/purpling of
the deciduous leaf margin; this ‘scorching’ starts at the tip of monocotyledonous
leaves. Eventually the whole of the leaf is affected by the loss of green and with
increasing distortion.
Magnesium is very soluble within the plant. Older leaves suffer from
magnesium deficiency as the plant removes magnesium from the older
leaves to support the younger leaves. The veins remain dark green and
there is yellowing in between the veins.
Iron deficiency only appears on the younger leaves because it is
immobile (insoluble) in the plant. Continued deficiency leads to the
green of the leaf veins gradually being bleached progressively from
the leaf tip end.
The top leaf is showing no deficiencies and is the normal dark green colour. The
bottom leaf has started to lose the dark green colour and there is evidence of
purple spotting as shown by the red arrow on the leaf.
Molybdedum deficiency symptoms are uncommon, but often starts with a breakdown of the leaf cells –
see purple spots on leaf shown below (indicated by red arrow). Typically the leaf margin gradually
deteriorates until there is an overall yellowing/browning of the leaf except the leaf tip.
In other plants there is a severe reduction of the leaf blade e.g. ‘whiptail’ in cauliflowers.