Tomato - Chlorosis
Symptoms
The older leaves become chlorotic, later necrotic, starting from the leaf edges.
At severe deficiency, the intercostal areas of the leaves may become chlorotic, too.
Whitish, necrotic dots develop within the chlorotic areas.
Causes
Potassium deficiency on the leaves.
Excess salinity may cause similar symptoms, this can be controlled by measuring the electrical conductivity (EC) of the nutrient solution.
Tomato - Chlorosis
Symptoms
The older leaves become chlorotic, later necrotic, starting from the leaf edges.
At severe deficiency, the intercostal areas of the leaves may become chlorotic, too.
Light brown and whitish, necrotic dots develop within the chlorotic areas.
Causes
Potassium deficiency on the leaves.
Excess salinity may cause similar symptoms, this can be controlled by measuring the electrical conductivity (EC) of the nutrient solution.
Tomato - Discolouration
Symptoms
Glasshouse grown tomatoes will often express potassium deficiency as blotchy ripening. When fruits turn red some areas remain green.
The symptoms are sometimes visible in field grown tomatoes, too.
Causes
Potassium deficiency on fruits
Potassium deficiency made worse by
- Acidic soils (low pH)
- Sandy or light soils (leaching)
- Drought conditions
- High rainfall (leaching)
- or heavy irrigation
- Heavy clay (illite) soils
- Soils with low K reserves
- Magnesium rich soils
Potassium is important for
- Coenzyme functions
- Protein synthesis
- Stomatal function
- Tugor potential
- Sugar degree
