Calcium and boron deficiency - Lettuce

Symptoms
With calcium deficiency roots of lettuce are short and very much ramified. They look scrubby, sometimes slimy, and are brown in color. Particulary the root tips turn black. Boron deficiency causes poorly developed roots too. They also look scrubby, as a great many of very short, branched secondary roots arise. Roots show browning and die off with severe deficiency.

Reasons
Calcium deficiency on roots (middle) compared to boron deficieny (right) and to optimum supply (left)

Symptoms
With calcium deficiency growth of lettuce is reduced and leaves are more wavy than normal. Starting on leaf margins or tips of young leaves, brown or grey lesions develop. This symptom is called 'tip-burn'. With progressing Ca-deficiency the leaves begin to die from tips and margins inwards. Next the symptoms spread over the older leaves. The dead leaf tissue is greyish green. If calcium deficiency occurs during early stage of development, growth is severely stunted and no heads are formed.

Reasons
Severe Calcium Deficiency Symptoms may be confused with boron deficiency, which also starts on the youngest leaves. But boron deficiency is much more concentrated on the growing point and no lesions are spread over the leaves.

Symptoms
With calcium deficiency growth of lettuce is reduced, leaves are dark green and more wavy than normal. Then, starting on leaf margins or tips of young leaves, brown or grey lesions develop. This symptom is called 'tip-burn'. With progressing Ca-deficiency the leaves begin to die from tips and margins inwards and the symptoms spread over the older leaves. The dead leaf tissue is greyish green. If calcium deficiency occurs during early stage of development, growth is severely stunted and no heads are formed.

Reasons
Severe Calcium Deficiency Symptoms may be confused with boron deficiency, which also starts on the youngest leaves. But boron deficiency is much more concentrated on the growing point and no lesions are spread over the leaves.

Symptoms
With calcium deficiency growth of lettuce is reduced and leaves are more wavy than normal. Young leaves show fade brown necrosis on their leaf tips or leaf margins. This symptom is called 'tip-burn'.

Reasons
Calcium Deficiency

Symptoms
With calcium deficiency roots are short and very much ramified. They look scrubby and sometimes slimy and are brown in color. Particulary the root tips turn black.

Reasons
Calcium deficiency on roots (left-hand side) compared to healthy roots

Symptoms
With calcium deficiency roots are short and very much ramified. They look scrubby and sometimes slimy and are brown in color. Particulary the root tips turn black. The greenish discoloration is no symptom of Ca- deficiency. Seemingly the pots with nutrient solution let some light inside, which causes green color.

Reasons
Calcium deficiency on roots (right side) compared to healthy roots (left side).