Role of Manganese in Citrus Production

Manganese and yield

Both soil application and foliar sprays of manganese increase yields in deficient trees. This is mainly as a result of increasing the number of fruit per tree.

Manganese and fruit number

Yield increases as a result of manganese nutrition are mainly due to a higher number of fruit per tree, as can be seen on Balady oranges in Egypt.

Mn and Zn combined and yield

Manganese deficiency is often associated with zinc and iron deficiencies. These are common on calcareous soils. In practice, a combined foliar application of Zn and Mn is often more effective in alleviating the respective deficiency symptoms, than single sprays on their own.

Mn/Zn sprays - effects on quality

Manganese, often in association with zinc, increases TSS contents of the fruit. The image above shows quality improvement on mandarins in India. 

Manganese and vitamin C content

Manganese can also improve the ascorbic acid content of the fruit. As a result, manganese has little influence on the TSS/Acid ratio and this combination of improved sugars and acidity content produces more desirable fruit for the consumer.

General guidelines for manganese application

Persistent, severe manganese deficiency reduces cropping, growth and yield. Manganese is involved with photosynthesis, efficient use of N, protein metabolism and enzyme activation. Both soil application and foliar sprays increase yields in deficient trees. This is mainly as a result of increasing the number of fruit per tree.