Manganese deficiency - Lettuce

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.

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.