Boron deficiency - Lettuce

Symptoms
With boron deficiency, plants are severely stunted and leaf color tends to be darker green than normal. The leaves are stiff and don't expand properly. Youngest leaves show necrotic blotches near their margins, which look like 'tip-burn'. Often young leaves develop chlorotic spots or they are completely yellow. With severe boron deficiency the growing point dies off.

Reasons
Boron deficiency on leaves Symptoms may be confused with calcium deficiency, which also starts on the youngest leaves. But boron deficiency is much more concentrated on the growing point. In opposite to calcium deficiency there spread no lesions over the leaves.

Symptoms
With boron deficiency, plants are severely stunted and color of the outer leaves tends to be darker green than normal. The leaves are stiff and do not expand properly. Young leaves show necrotic blotches near their margins, like 'tip-burn'. Often youngest leaves are completely yellow. With severe boron deficiency the growing point dies off.

Reasons
Boron deficiency on leaves Symptoms may be confused with calcium deficiency, which also starts on the youngest leaves. But boron deficiency is much more concentrated on the growing point and in opposite to calcium deficiency no lesions are spread over the leaves.

Symptoms
Plants are severely stunted and color of the outer leaves tends to be darker green than normal. Leaves are more wavy and arched, they are stiff and don't expand properly. Especially butterhead lettuce builds only a rosette and no head, which results in high yield losses.

Reasons
Boron deficiency on leaves (right) Symptoms may be confused with calcium deficiency, which also starts on the youngest leaves. But boron deficiency is much more concentrated on the growing point and in opposite to calcium deficiency no lesions are spread over the leaves.

Symptoms
Boron deficiency disturbs root development. Roots look scrubby, as a great many of very short, branched lateral roots arise. They show a brownish coloration and with severe deficiency root tips die off.

Reasons
Roots of Boron deficient plant (above) compared to healthy roots (below)

Symptoms
Symptoms of boron deficiency are severely stunted plants and darker green leaf color than normal. Especially butterhead lettuce builds only a rosette and no head, which results in high yield losses. The youngest leaves are stiff and show necrotic mottling on the margins and between the veins. With severe deficiency, the growing point dies and the youngest folded leaves show brown spots. The roots are poorly developed and brownish. They look scrubby, because a great many very short, branched lateral roots arise. With severe deficiency root tips die off. The greenish discoloration of the roots is no symptom of boron deficiency. Seemingly the pots with nutrient solution let some light inside, which caused green color.

Reasons
Boron deficiency (right) compared to optimum supply (left) Symptoms may be confused with calcium deficiency, which also starts on the youngest leaves. But boron deficiency is much more concentrated on the growing point and in opposite to Ca-deficiency no lesions spread over the leaves.

Symptoms
Boron deficiency causes poorly developed, brownish roots. They look scrubby, as a great many of very short, branched lateral roots arise. With severe deficiency root tips die off.

Reasons
Roots of boron deficient plant (right) compared to healthy roots