Iron toxicity is a yield decreasing physiological disorder ascribed to the excessive uptake of Fe and sometime together with Mn ascribed to young acid sulphate soils, alluvial or colluvial clayey soils mainly acidic. The symptoms vary with the crop and the intensity is decided by the situation and mainly deficiency of P, K, Ca, Mg and Zn. In rice it is characterized by a reddish brown mottling (bronzing) or in some cultivars, oranging or yellowing spreading downwards from the tips of the older leaves followed by the drying of the leaves. Roots are scanty, coarse and often dark brown due to the coatings of ferric oxide. Incase of banana the toxicity of Fe causes marginal blackening followed by necrosis of the leaves. Planting tolerant varieties in Fe toxic soils is a cheap way to overcome the problem. The application of lime and balanced fertilization with the deficient nutrients mitigate iron toxicity.
