Symptômes
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.
Raisons
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.
Symptômes
Potassium deficiency causes longer main roots than normal and only few secondary roots. They show yellowish color. Often roots are slimy .
Raisons
Potassium deficiency on roots
Symptômes
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.
Raisons
Potassium deficiency on head and roots
Symptômes
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.
Raisons
Potassium deficiency (right) compared to optimum supply(left)
Symptoms 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.
Symptômes
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.
Raisons
Potassium deficiency on leaves
Lettuce (field grown): 5 l/ha 14 to 20 days after the 4 to 6 leaf stage. Repeat if necessary at 10 day intervals. Note: Final application to be made at least one month before harvest. Water rate: 500 l/ha.
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