Copper in plants:
Copper is one of the most immobile micronutrients or trace elements needed in very small amounts and required in all plant parts
Functions as a catalyst in photosynthesis and respiration; essential for the overall metabolism in plants
Absorbed as cupric ions (Cu2+). Reversibly oxidised from Cu+ to Cu2+
Associated with certain enzymes involved in redox reactions. Forms a component of enzymes such as phenolases, ascorbic acid oxidase and tyrosinase.
It is a constituent of plastocyanin, for this reason plays a role in photophosphorylation.
Maintains the carbohydrate - nitrogen balance.
However higher concentration of copper is toxic to plants
Deficiency of copper in plants:
(i) Plant shows a lack of growth; petioles bend downward; leaves appear light green and become dry at the tips; with severe copper deficiency leaves dried, wrinkled, twisted, broken and eventually leads to death of plant
(ii) Causes die-back disease of shoots especially in Citrus plant.
(iii) Reclamation disease or ‘yellow tip’ is a deficiency symptom of copper in plant. It affects oat cereals plants, sugar beet and leguminous crops.
(iv) Exanthema disease is another copper deficiency in plant, produced by soil factors and brought about by soil microorganisms
(v) Deficiency of copper affects flavor, storage ability, and sugar content of fruits and can affect yields as well.
One way to treat this deficiency is by application of copper sulphate.