Role of manganese in apple production
Manganese effect at growth stages
| Stage | Manganese effect |
| Bud Burst - Start of Flowering | To maximize tissue growth |
| Fruit Fill - Maturity | Along side with phosphorus will promote fruit coloration |
Manganese deficiencies in apples
Manganese deficiency is first seen as light green spots on leaf margins and as an interveinal mottling. Usually the recently matured leaves in early summer growth are the first to show symptoms.
Interveinal areas then become yellow, with prominent green veins. When severe, leaves and shoots become stunted although generally there is little change from normal leaf size and shape.
Excessive amounts of available manganese uptake – associated with low pH soils and poor drainage – results in necrosis of trunk and branch bark (measles).
Manganese and background fruit color
Manganese sprays can also be applied to improve the background, green color in fruit.
Manganese and leaf quality
Trials with Golden Delicius apples in Italy show that foliar manganese, applied at least twice in the spring, has proven to be most effective at improving leaf color and minimizing leaf drop and blotchiness.
