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Soils and Plant Nutrition Home

Soil Properties

Tree Fruit Nutrition


  Essential Nutrients


Copper (Cu)

Form used by plants:

Cu+ or Cu2+

Important functions:

  • Important enzyme component (laccase and other oxidase enzymes) and in the production of vitamin A

  • Critical in the role of photosynthesis, protein and carbohydrate metabolism, and respiration

  • Contributes to the color and flavor development in fruits and vegetables

  • Necessary in the formation of seed and chlorophyll

  • Involved in the use of Fe by plant

  • Stimulates lignification of all plant cell walls

Ideal foliage range for apple leaves:

6-40 ppm

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Ideal fruit concentration:

Ideal soil range:

>0.6ppm (using DTPA method; this is not total Cu but available Cu).

Soils deficient in Cu are rare.

Copper is strongly sorbed by soil components and is not readily mobile.

Best indicators: 

Mobility in plant:

Not remobilized within plant

Deficiency symptoms:

CuDef.JPG (8705 bytes) CuDefBark.JPG (10590 bytes)

Vegetation symptoms: “Wither tip” occurs.  Leaf margin chlorosis of young leaves first.  Shoots grow normally at first but in mid-June the terminal leaves turn yellow, wither and fall.  Dieback of terminal shoots; stunted growth; poor pigmentation; wilting and eventual necrosis of leaf tips.  Can occur over part or most of the tree.

Fruit symptoms: undersized fruit and reduced yield

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Increased risk of deficiencies:

Availability decreases as pH increases but more closely associated with organic matter content

Excess problems/Interactions with other elements:

  • Excess Cu may reduce Mo (molybdenum) and Mn (manganese) uptake by plants
  • Excess Cu encourages Fe (iron) deficiency
  • Excess phosphate may encourage Cu deficiency
  • Heavy nitrogen fertilization increases Cu deficiency

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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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