Avocados are susceptible to iron deficiency, and the ideal pH to grow them satisfactorily is 5.5 to 6.5. Conditions higher than pH 7 will probably cause iron deficiency. The symptomatology of iron deficiency is usually manifested as an interveinal chlorosis of young leaves while the veins remain green -hence the name iron deficiency chlorosis. Research on metabolism, biochemistry and physiology of iron in plants and avocado is discussed as well as approaches to control iron deficiency chlorosis in avocado. The best method to avoid iron deficiency would be to avoid planting avocados on highly calcareous soils, or to use rootstocks which are resistant to lime-induced chlorosis, on the other hand, several strategies have been developed to alleviate the problem of iron chlorosis. Apparently the only possibility to control iron chlorosis in established orchards is by soil applications of Fe chelates, since applications by foliar sprays have not been successful on a commercial scale. In the long term, development and use of avocado rootstocks with tolerance to calcareous soils or more Fe-efficient cultivars still seems to be the most economical solution to permanently control Fe chlorosis.

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