Phosphorus
Role of Phosphorus
- Phosphorus contributes to the early development of the crop and early tuberization.
- It has been reported that phosphorus increases the number of tubers per plant.
Relative high rates are applied to seed crops because phosphorus may reduce virus infection.
Since phosphorus is not easily leached and potatoes give a high level of response, in non-phosphorus fixing soils it is possible to concentrate phosphorus fertilization on the potato crop, thus reducing the application required for other crops in the rotation.
Application of Phosphorus
Phosphorus is not taken up easily by the potato and does not move in the soil easily.
For this reason:
- the applied dose is higher than the uptake
- the total amount is given before or at planting
- the phosphorus is preferably placed (banded) instead of broadcasted
- the phosphorus is given in a water soluble form
Deficiency symptoms
- Plants stunted
- Darker than normal colour
- Lower leaf surface gray-green
- Leaflets roll upward, severly if deficiently is severe
Phosphorus deficiency