Potassium deficiency-Grapevines

Symptoms
Intercostal chlorosis starts on the leaf margins and spreads to the internal area of mature leaves. At the margins, necrotic zones develop. The veins remain green for a certain time. Potassium deficiency results in different symptoms, dependent on the date of appearance and the weather conditions.

Causes
Potassium deficiency

Symptoms
Interveinal yellowing (white vine varieties) or reddening (red varieties) starts on the leaf margins and spreads over the internal area of older leaves. The veins remain green for a certain time. Later, necrotic areas appear on the leaf margins, which perforate easily. Symptoms of slight deficiency are shown on leaves near grapes firstly. Generally potassium deficiency symptoms are most apparent in mid to late summer.

Causes
Potassium deficiency

Symptoms
Interveinal yellowing (white vine varieties) or reddening (red varieties) starts on the leaf margins and spreads over the internal area of older leaves. The veins remain green for a certain time. Later on the leaf margins necrotic areas appear, which perforate easily. Symptoms of slight deficiency are shown on leaves near grapes firstly. Generally potassium deficiency symptoms are most apparent in mid to late summer.

Causes
Potassium deficiency

Symptoms
Interveinal yellowing (white vine varieties) or reddening (red varieties) starts on the leaf margins and spreads over the internal area of older leaves. The veins remain green for a certain time. Later on the leaf margins necrotic areas appear, which perforate easily. Symptoms of slight deficiency are shown on leaves near grapes firstly. Generally older leaves are affected first.

Causes
Potassium deficiency Very sandy soils and those that have been leveled (removing the topsoil) suffer worst from potassium deficiency. Deficiencies are most apparent in mid to late summer.

Symptoms
Interveinal yellowing (white vine varieties) or reddening (red varieties) starts on the leaf margins and spreads over the internal area of older leaves. The veins remain green for a certain time. Later on, the leaf margins and intercostal areas become necrotic and perforate easily. Symptoms of slight deficiency are shown on leaves near grapes firstly. Generally older leaves are affected first. K deficiency is one reason among others for a physiological disorder that makes the grape berries wilt and dry.

Causes
Potassium deficiency Very sandy soils and those that have been leveled (removing the topsoil) suffer worst from potassium deficiency. Deficiencies are most apparent in mid to late summer.