The science and technology of iron in plant nutrition future outlook

Abstract

The direction and balance of work on iron has been assessed on the basis of recent published work.

Greatest emphasis is being placed on the physiology of iron, particularly absorption and related studies on genotypic variation. There is surprisingly little work on the efficacy of different treatments particularly spray application. Few studies have been recently directed toward establishing diagnostic levels of iron in soils and plants.

Rice, maize, soybean and to a lesser extent sorghum, are the main crops being studied but groundnuts, an important crop which is susceptible to iron deficiency, has been little studied.

Most of the iron studies emanate from the USA, India, West Germany, Brasil, Australia, Japan and Spain. An imbalance is indicated with little work coming from countries where the deficiency is common such as those around the Mediterranean and in the Middle East.

It is optimistically expected that major advances in combatting iron problems will continue to be made in the next 10–20 years by utilising genotypic variation. The door that has been opened by soybean and sorghum will permit many other crops to pass through; already there are clear signs that many crops including rice, pigeon pea, chick pea, oats, barley, maize and groundnuts possess sufficient genetic variation with regard to iron absorption to provide the basis for a breeding and selection programme.

Key words:

• Iron deficiency
• iron toxicity
• review of research