Chlorotic, undersized leaves of citrus especially pronouned in older leaves due to nitrogen deficiency.

Because nitrogen is mobile in the plant, chlorosis is more pronouned in older leaves. Nitrogen deficiency symptoms may be confused with symptoms caused by agents that restrict root growth and reduce nutrient uptake, including root pathogens, soil compaction, and poor drainage. Credit: Laurence R. Costello, UCCE San Francisco-San Mateo
Credit: Laurence R. Costello, UCCE San Francisco-San Mateo