Potassium
Major function
- Potassium has a major function in the starch and energy metabolism. It has an important function in the transport of the other nutrient elements.
- Potassium is taken up by the plant in large quantities, but is sufficiently available in many soils in which potatoes are cultivated.
Yield and quality
- Potassium does not always affect yield, but it has relatively more influence on the quality of the crop.
- It is often assumed that yield is reduced when crops show deficiency symptoms.
- High potassium may reduce the dry matter content of tubers.
- Potassium deficiency enhances susceptibility to black spot and may cause enzymatic discoloration on the cut surface of raw tubers.
- After cooking discolouration is also more severe with potassium deficiency.
- Where harvest systems and handling operations that may cause internal bruising (black spot) are used, high dosages of potassium are given to reduce black spot problems.
Deficiency symptoms
- Symptoms appear on youg, full sized leaves
- Leaflets become rugose (crinkled)
- Leaves take on a scorched appearance with black pigmentation and necrotic (dead tissue) edges
Potassium 1------Potassium 2------ Potassium 3
