Soya bean - Growth retardation
Symptoms
Leaves usually show a dark green to bluish tint. The displayed photo shows yellow chlorosis.
Because of the effect that P deficiency has on retarding overall growth, striking foliar symptoms that are evidence
of deficiency in certain other nutrients, for example N and K, are sometimes observed.
Causes
Phosphorus deficiency
The uptake of P is inhibited in acidic as well as in cool, wet soils.
Soya bean - Chlorosis
Symptoms
Plants suffering from P deficiency usually show a dark green to bluish tint on their foliage. In the displayed picture, leaves show an even chlorosis and a dark, brownish tint on the interveinal fields.
Causes
Phosphorus deficiency
Soybeans require relatively large amounts of P, especially at pod set.
The uptake of P is inhibited in acidic as well as in cool, wet soils.
Soya bean - Chlorosis
Symptoms
Plants suffering from P deficiency usually show a dark green to bluish tint on their foliage.
In the displayed picture, leaves show an even yellow chlorosis and a beginning light brown necrosis on the marginal area of the leaf base.
Causes
Phosphorus deficiency
Soybeans require relatively large amounts of P, especially at pod set.
The uptake of P is inhibited in acidic as well as in cool, wet soils.
Soya bean - Chlorosis
Symptoms
P deficient plants suffer from growth retardation and sparse foliage.
Leaves usually show a dark green to bluish tint. In the displayed case, older leaflets show interveinal chlorosis and necrosis.
Light brown necrotic blotches coalesce along the leaf margin.
Causes
Phosphorus deficiency
Soybeans require relatively large amounts of P, especially at pod set.
The uptake of P is inhibited in acidic as well as in cool, wet soils.
Soya bean - Chlorosis
Symptoms
Leaves usually show a dark green to bluish tint. In the displayed case, older leaflets show interveinal chlorosis and necrosis.
Light brown necrotic blotches coalesce towards the leaf margin.
Causes
Phosphorus deficiency
Soybeans require relatively large amounts of P, especially at pod set.
The uptake of P is inhibited in acidic as well as in cool, wet soils.
Phosphorus deficiency made worse by
- Acidic or very alkaline (calcareaus) soils
- Low organic matter
- Cold or wet conditions
- Crops with a poorly developed root system
- Soils with low P reserves
- Soils with a high phosphate capacity
- Iron rich soils
Phosphorus is important for
- Increased energy transfer
- Improved synthesis of proteins
- Greater formation of nucleic acids
- Stronger cell membranes due to increase in phospholipids
