Symptoms
Leaf margins turn yellow to light brown, later dark brown. With ongoing deficiency the margin weathers and curls up.
Leaves are less waxy.
Reasons
Potassium deficiency on leaves.
(photo: broccoli)
Cauliflower - Necrosis
Symptoms
Potassium deficient white cauliflower shows light brown or white necrosis on the edges. Margins wither and curl up. Leaves are less waxy.
With ongoing deficiency necrosis progresses from the margins to the middle of the leaflets.
Reasons
Severe Potassium deficiency on leaves.
(photo: cabbage)
Cauliflower - Necrosis
Symptoms
Leaf margins turn yellow to light brown, later dark brown. With ongoing deficiency the margin weathers and curls up.
Leaves are less waxy.
Reasons
Potassium deficiency on young plant
Potassium deficiency made worse by
Acidic soils (low pH)
Sandy or light soils (leaching)
Drought conditions
High rainfall (leaching)
or heavy irrigation
Heavy clay (illite) soils
Soils with low K reserves
Magnesium rich soils
Potassium is important for
Resistance to cold injury and drought
High yields through increased biomass and head weight
Consistent, early and evenly matured marketable crop