Nitrogen:
Leaves to show
effects first: Old
Entire plant
turns yellow green, and the older leaves become more yellowish than
the younger.
Older leaves do
not die unless deficiency is extreme.
Phosphorus:
Leaves to show
effects first: Old
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.
Premature leaf
drop-off.
Similar to
nitrogen deficiency.
Calcium:
Leaves to show
effects first: New
Mild deficiency:
Smaller, distorted new leaf growth. Reduced leaf tissue, with the
central vein persisting.
Leaves often
cupped, rather than flat
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 though they have tried to grow
and got jammed in a small space.
Severe
deficiency: New growth almost entirely white. Leaves are tiny
deformed stumps. Growing points for both shoot and root
die.
Damage and die
off growing points.
Yellowish leaf
edges.
Magnesium:
Leaves to show
effects first: Old
Indicots:
Yellowing of older leaves that starts from the edges 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.)
Yellow
spots.
Potassium:
Leaves to show
effects first: Old
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.
Yellow areas,
then withering of leave edges and tips.
Sulfur:
Leaves to show
effects first: New
Similar to
nitrogen deficiency
Iron:
Leaves to show
effects first: New
Reduced
chlorophyll in new growth. Leaves and stem are about the same
shade. Growing tips of Ceratophyllum become pinkish and then white.
Egeria 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 patches 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.
Leaves Turn
Yellow.
Greenish nerves
enclosing yellow leaf tissue.
First seen in
fast growing plants.
Manganese:
Dead yellowish
tissue between leaf nerves.
Copper:
Dead leaf tips
and withered edges.
Zinc:
Leaves to show
effects first: Old
Yellowish areas
between nerves, Starting at leaf tip and
edges.
Boron:
Leaves to show
effects first: New
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.
Dead shoot tips,
new side shoots also die.
Molybdenum:
Leaves to show
effects first: Old
Yellow spots
between leaf nerves, then brownish areas along
edges.
Inhibited
flowering