Lettuce - Chlorosis
Symptoms
The whole plant turns greenish/yellow and the leaves are smoother than normal. At severe deficiency, necrotic spots develop on the margins and intercostal areas of the older leaves. The veins remain darker green than the intercostal fields. Growth is not inhibited.
Reasons
Manganese deficiency
With nitrogen deficiency, the plant also turns yellow, but growth is restricted clearly then.
With sulphur deficiency, the symptoms start on the younger leaves, the veins do not remain green then.
Lettuce - Chlorosis
Symptoms
With manganese deficiency the whole plant turns greenish/yellow, whereas the leaf veins often remein dark green.
Growth of heads is not severely affected.
Reasons
Manganese deficiency
Symptoms may be confused with nitrogen, sulfur or manganese deficiency.
With N deficiency, the whole plant becomes yellowish in color, but the veins do not remain green and growth is heavily restricted.
Sulphur deficiency also causes a yellowish color of the lettuce leaves, but in this case the symptoms start at the younger leaves and growth is more restricted.
Also magnesium deficiency shows yellowish zones between the veins, but the color is more orange-yellow and not greenish-yellow as with manganese deficiency.
Lettuce - Growth retardation
Symptoms
With manganese deficiency the whole plant turns greenish/yellow whereas the veins remain slightly darker than the intercostal field.
Prolonged deficiency causes necrotic spots on the margins and intercostal areas of the older leaves.
Growth of heads is moderately affected.
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Reasons
Manganese deficiency (right) compared to otimum supply (left)
Symptoms may be confused with nitrogen, sulfur or manganese deficiency.
With N deficiency, the whole plant becomes yellowish in color, but the veins do not remain green and growth is heavily restricted.
Sulphur deficiency also causes a yellowish color of the lettuce leaves, but in this case the symptoms start at the younger leaves and growth is more restricted.
Also magnesium deficiency shows yellowish zones between the veins, but the color is more orange-yellow and not greenish-yellow as with manganese deficiency.
Manganese deficiency made worse by
- Organic soils
- Sandy soils
- High pH
- Cold wet periods
- Fluffy soils
Manganese is important for
- Nitrate reduction
- Photosynthesis
- Protein synthesis
- Maintains strong growth and development