Lettuce - Necrosis
Symptoms
Symptoms of zinc deficiency on lettuce start on older or medium leaves. They develop papery, grey-green necrosic spots with brown borders on leaf margins. Necrotic areas increase quickly and flow together.
Leaf parts which are not subjected to light remain green.
Growth is restricted.
Zinc deficiency in an early stage of development causes rosetting, no heads are formed.
Reasons
Zinc deficiency on leaves compared to optimum supply
Lettuce - Growth retardation
Symptoms
Symptoms of zinc deficiency on lettuce start on leaf margins of older or medium leaves. They develop papery, grey-green necrotic spots with brown borders, mostly without preceding chlorosis. Necrotic areas increase quickly and flow together.
Leaf parts which are not subjected to light, remain green.
Growth is restricted.
Zinc deficiency in an early stage of development causes rosetting, no heads are formed.
Reasons
Zinc deficiency
Lettuce - Growth retardation
Symptoms
Symptoms of zinc deficiency on lettuce start on leaf margins of older or medium leaves. They develop papery, grey-green necrotic spots with brown borders, mostly without preceding chlorosis. Necrotic areas increase quickly and flow together.
Leaf parts which are not subjected to light, remain green.
Growth is restricted.
Zinc deficiency in an early stage of development causes rosetting, no heads are formed.
Reasons
Zinc deficiency
Lettuce - Growth retardation
Symptoms
Symptoms of zinc deficiency on lettuce start on leaf margins of older or medium leaves. They develop papery, grey-green necrotic spots with brown borders, mostly without preceding chlorosis. Necrotic areas increase quickly and flow together.
Leaf parts which are not subjected to light, remain green.
Growth is restricted. Zinc deficiency in an early stage of development causes rosetting, no heads are formed.
Growth of roots is slightly restricted.
Reasons
Zinc deficiency on leaves and roots
Lettuce - Chlorosis
Symptoms
Symptoms of zinc deficiency on lettuce start near leaf margins of older or medium leaves. They develop papery, grey-green necrotic spots with brown borders, mostly without preceding chlorosis. Necrotic areas increase quickly and flow together.
Leaf parts which are not subjected to light, remain green.
Reasons
Commencing zinc deficiency on leaves
Zinc deficiency vs. optimum made worse by
- Organic soils
- High pH soils
- Soils rich in phosphorus
- Soils receiving high phosphorus application
- Cold wet conditions
Zinc is important for
- Enzyme activation, but also for synthesis of growth regulators
