is a component of certain enzymes and proteins,
adenosine triphosphate (ATP), ribonucleic acids (RNA),
deoxyribonucleic acids (DNA) and phytin. ATP is involved
in various energy transfer reactions, and RNA and DNA
are components of genetic information.
Phosphorus (P) deficiency
Figure 11 is severe phosphorus (P) deficiency during
flowering. Fan leaves are dark green or red/purple, and
may turn yellow. Leaves may curl under, go brown and
die. Small-formed buds are another main symptom.
Phosphorus deficiencies exhibit slow growing, weak
and stunted plants with dark green or purple
pigmentation in older leaves and stems.
deficiency during flowering is normal, but too much
shouldn't be tolerated. Red petioles and stems are a
normal, genetic characteristic for many varieties, plus
it can also be a co-symptom of N, K, and
Mg-deficiencies, so red stems are not a foolproof sign
of P-deficiency. Too much P can lead to iron deficiency.
Purpling: accumulation of anthocyanin pigments;
causes an overall dark green color with a purple, red,
or blue tint, and is the common sign of phosphate
deficiency. Some plant species and varieties respond to
phosphate deficiency by yellowing instead of purpling.
Purpling is natural to some healthy ornamentals.