ABSTRACT
Iron (Fe) has been known from prehistoric times. It is the fourth most common element in the crust of the earth and is the most common element in the entire mass of the earth. According to dictionaries, the name iron derives from Middle English and Old English words of unknown meaning, and the chemical symbol Fe comes from the Latin ferrum for rmness. In crop production, Gris (1843) and Wallihan (1965) noted that growth and appearance of chlorotic grape vines were improved by foliar application of Fe salts. The essentiality of Fe as a nutrient for plants was demonstrated in about 1860 by Julius von Sachs, who included Fe in nutrient solutions for hydroponics (Römheld and Nikolic, 2007). In plants, Fe deciency produces easily recognized symptoms that appeared readily in research on essentiality of nutrients so that Fe was recognized as an essential element at the same time as the macronutrients.
