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Soils and Plant Nutrition Home

Soil Properties

Tree Fruit Nutrition


  Essential Nutrients


Calcium (Ca)

Form used by plants:


Important functions:

  • Important in cell wall and membrane construction

  • Regulates nutrient uptake by roots and movement in plant

  • Necessary for development of firm fruit

Ideal foliage range for apple leaves:

1.2-1.6%  (However, do not rely on leaf analysis to identify Ca deficiency).  Vegetative growth out competes fruit for available Ca.

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Ideal fruit concentration:

0.01-0.03% of dry weight (fruit flesh)

Ideal soil range:

600-4000 ppm

Calcium is strongly sorbed by soil components and thus not mobile.

Best indicators: 

Fruit analysis- observe fruit for bitter pit (see photo below) or cork spot. May see premature shedding of blossoms and buds.

Mobility in plant:

Not remobilized within plant

Deficiency symptoms: bitterPit copy.JPG (10461 bytes) 

Fruits have a low ability to attract Ca and instead it is utilized by growing shoots and leaves.

Fruit symptoms: bitter pit (see photo), cork spot, senescent breakdown, watercore.  Maturity will be hastened (if not monitored, may lead to significant drop and poor storageability).

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Increased risk of Ca deficiencies on:

  • Overfertilized plots (excess Mg or K in soil makes it more difficult for roots to take up Ca; too much N stimulates vegetative growth which will take Ca away from fruit)

  • Excessively pruned plots (due to stimulation of vegetation)

  • Areas with B deficiencies because this may reduce calcium movement

  • Excessively large fruit should be avoided

  • Water-stressed areas or areas subject to wide fluctuations in moisture supply

Excess problems/Interactions with other elements:

*see increased risk section above

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Last updated: 14 February, 2001


Washington State University - Tree Fruit Research & Extension Center
1100 N. Western Ave. * Wenatchee WA 98801
phone: 509-663-8181 * fax: 509-662-8714                                                                                                                                                                                     

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