Magnesium deficiency-Apples

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® HYDROMAG™

Apples: 4 l/ha (1.6 l/acre) after petal fall. In cases of severe deficiency, apply also before flowering (around pink bud stage). On russet sensitive varieties delay application until 6 weeks after petal fall. Water rate: 200 to 1,000 l/ha (80 to 400 l/acre). Pommiers: 4 l/ha après la chute des pétales. En cas de carence sévère appliquer aussi avant la floraison (stade boutons roses). Sur les variétés sensibles au russetting retarder les applications jusqu'à 6 semaines après la chute des pétales. Volume d'eau: 200-1.000 l/ha.