Apples - Chlorosis
Symptoms
Leaves develop inteveinal necrosis or necrotic blotches from midrib area on older leaves first
Reasons
Magnesium deficiency
Potassium deficiency perhaps produces similar symptoms, but starts at 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 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® BUD BUILDER™WP
Apples: In the Spring apply 5 to 10 lbs/acre applied at bud burst. Reapply after fruit set during sizing in 10 to 14 day intervals. 5-10 lbs/acre applied post-harvest before leaf senescence. Water rate: minimum 25 gallons/acre. Foliar application of Bud Builder may leave a white residue-deposit on the leaf or crop when applied close to harvest.
Read more about YaraVita® BUD BUILDER™WPYaraVita® MAGPHOS™
Apples: 4 to 6 applications of 1-2 quarts/acre from end of flowering. Repeat applications at 10 to 14 day intervals through color break. Water rate: 50 to 100 gallons/acre.
Read more about YaraVita® MAGPHOS™YaraVita® MAGTRAC™
Apples: 1-2 quarts/acre after petal fall. Repeat if necessary at 10 to 14 day intervals. In cases of severe deficiency apply also before flowering (around pink bud stage). On russet sensitive varieties delay applications until 6 weeks after petal fall. Water rate: 20 to 100 gallons/acre.
Read more about YaraVita® MAGTRAC™