Magnesium deficiency-Apples | Yara South Africa

Symptoms
Symptoms appear first as chlorosis between the main veins, starting on older leaves. Then develop to interveinal necrosis or necrotic blotches along the main vein. Often leaf margin remain green. Apple and other fruits sometimes right away develop necrosis without preceding chlorosis.

Reasons
Magnesium deficiency Potassium deficiency perhaps produces similar symptoms, but starts on the leaf margins.

Apples - Chlorosis

Symptoms
Symptoms appear first as chlorosis between the main veins starting on older leaves. Then develop to interveinal necrosis or necrotic blotches along the main vein. Often leaf margin remain green. Apple and other fruits somtimes right away evolve necrosis without preceding chlorosis.

Reasons
Magnesium deficiency Potassium deficiency perhaps produces similar symptoms, but starts at leaf margins.

Apples - Necrosis

Symptoms
Symptoms appear first as chlorosis between the main veins starting on older leaves. They develop to interveinal necrosis or necrotic blotches along the main vein. Often leaf margins remain green. Apple and other fruits sometimes evolve necrosis without preceding chlorosis.

Reasons
Magnesium deficiency Potassium deficiency perhaps produces similar symptoms, but starts at leaf margins.

Magnesium deficiency made worse by

Sandy soils
Acidic soils
Potassium rich soils
Soils receiving high potash applications
Cold wet periods

Magnesium is important for

New growth maintained green and vigorous
Fruit number and retention increased
Fruit size may be increased
Yields are greater

Yara recommended fertilizers for Magnesium

YaraVita MAGFLO 300

Apple: 3 to 4 l/ha after petal fall and repeated if necessary at 10 to 14 day intervals up to one month before harvest. On varieties sensitive to russetting, delay applications until 6 weeks after flowering. Water rate: 500l/ha minimum