Role of Copper in Citrus Production
Copper in citrus affects photosynthesis, plant protein production, pollen viability and therefore fruit set, respiration and water use efficiency.
Copper and quality - mandarins, India
Trials in India indicate that copper reduces acidity and increase the TSS/Acid ratio in mandarins.
Copper and vitamin C
Copper also has the tendency to improve the ascorbic acid content of the fruit.
Copper effect at growth stages
| Stage | Copper effect |
| Fruit Enlargement and Maturation | Prevent fruit corking |
See more on Citrus Growth Stages.
General guidelines for Copper application
Copper in citrus affects photosynthesis, plant protein production, pollen viability and therefore fruit set, respiration and water use efficiency. Over-use of copper based fungicide sprays can lead to toxicity. Tissue analysis are recommended to check for deficiencies or toxicities.
Copper deficiencies in Citrus
Symptoms of copper deficiency are rarely seen where copper based fungicides are applied. When copper is deficient the leaves are dark green and enlarged. Stems are more slender than normal and appear flat and angular. Limbs die back and gumming may occur under new bark or on fruits. Symptoms are more prominent in young citrus. Trees, which are copper deficient have poor flowering and therefore lower yields. Foliar sprays will correct any transient problems.
