Form used by plants:
Cu+ or Cu2+
component (laccase and other oxidase enzymes) and in the production of vitamin A
Critical in the role
of photosynthesis, protein and carbohydrate metabolism, and
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
lignification of all plant cell walls
Ideal foliage range for apple leaves:
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.
Mobility in plant:
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.
symptoms: undersized fruit and reduced yield
Increased risk of deficiencies:
as pH increases but more closely associated with organic matter
Excess problems/Interactions with other
- Excess Cu may reduce Mo (molybdenum) and
Mn (manganese) uptake by plants
- Excess Cu encourages Fe (iron) deficiency
- Excess phosphate may encourage Cu
- Heavy nitrogen fertilization increases Cu