Role of Nitrogen in Citrus Production

Nitrogen is a key component of enzymes, vitamins, chlorophyll and other cell constituents, which are essential for crop growth and development. Therefore, nitrogen is one of the most important nutrients needed for high citrus crop yields.

Nitrogen effect at growth stages

Stage Nitrogen effect
Flowering Boost yield and tree productivity
Fruit Set Maintain leaf growth, flowering and strong fruit set
Fruit Enlargement and Maturation Maintain yields and improve skin thickness and fruit acidity
Post Harvest Encourage active flush of foliage
See more on Citrus Growth Stages.

General guidelines for Nitrogen application

Optimum N-response varies according to citrus tree age. An annual programme of fertilizer-N is needed to ensure long-term productivity by replenishing nitrogen, which is removed by harvested fruit. Nitrogen is timed usually in 3-5 roughly equal split applications made during the citrus growing season and during periods of active root and tree/flower/fruit growth and uptake.

Nitrogen deficiencies in Citrus

Nitrogen deficiencies are rare because N is adequately applied in most citrus groves. Deficiencies will show when leaf N content drops below 2% DM. The entire leaf (including interveinal areas) becomes light green to yellow in colour and will drop early from the tree; in cases of severe deficiency, growth is uneven and stunted.