Potassium deficiency - Lettuce

Symptoms
Tips and margins of older leaves get chlorotic spots with increasing size which become necrotic later on. On account of scorched leaf margins leaves are deformed. With more severe deficiency the leaf color turns to mottled dark green and the plant appears wilted. Occasionally leaves are less crinkled than normal and shape of the leaves becomes more rounded. Growth of the plants is restricted, they do not form heads or the heads remain loose.

Reasons
Potassium deficiency Symptomes may be confused with high salt concentration of the growing substrate. In this case the veins of the leaves become brown in addition to dry leaf margins.

Symptoms
Potassium deficiency causes longer main roots than normal and only few secondary roots. They show yellowish color. Often roots are slimy .

Reasons
Potassium deficiency on roots

Symptoms
Tips and margins of older leaves get chlorotic spots with increasing size which become necrotic later on. On account of scorched leaf margins leaves are deformed. With more severe deficiency the leaf color turns to mottled dark green and the plant appears wilted. Maybe leaves are less crinkled than normal and shape of the leaves becomes more rounded. Growth of the plants is restricted, they do not form heads or the heads remain loose. Potassium deficiency causes longer main roots than normal and only few secondary roots. Often roots are slimy and yellowish in color.

Reasons
Potassium deficiency on head and roots

Symptoms
Symptoms of potassium deficiency start on older leaves. The leaf color turns to mottled dark green and the plant appears wilted. Tips and margins get chlorotic spots with increasing size which become necrotic later on. On account of scorched leaf margins leaves are deformed. On the photo necrotic areas appear along the main veins. More typical are scorched zones on the margins. Occasionally leaves are less crinkled than normal and shape of the leaves becomes more rounded.

Reasons
Potassium deficiency on leaves