Phosphorus deficiency - Strawberry

Symptoms
Symptoms begin at mature leaves. Leaves are dark green and a bit smaller than normal. With ongoing phosphorus deficiency leaf blades show a purple tint. Tinting becomes brighter as leaves age and approach early senescence.

Reasons
Phosphorus deficiency Petioles of phosphorus deficient leaves contain less then 700 ppm acetic acid soluble phosphate-phosphorus, dry basis.

Symptoms
Symptoms begin at mature leaves. Leaves are dark green and smaller than normal. With ongoing phosphorus deficiency leaf blades show a purple tint. Tinting becomes brighter as leaves age and approach early senescence.

Reasons
Severe phosphorus deficiency Petioles of phosphorus deficient leaves contain less then 700 ppm acetic acid soluble phosphate-phosphorus, dry basis.

Symptoms
The first indications of a deficiency are a dull, deep green or bluish-purple discoloration of the plant and a reduction in leaf size. As the deficiency worsens the upper surface of the leaves develops a dark, metallic sheen while the underside becomes reddish-purple. Mature leaflets show marginal chlorosis with subsequent dark brown necrosis, starting from the leaf tips.

Reasons
Phosphorus deficiency Symptoms are worse during cold and dry growing conditions and at high pH values, all of which render the P less available.