Micronutrient
With the advent of green revolution, the crop production scenario changed drastically. Crop production became input intensive since the high yielding varieties were very responsive to fertilizers and water. Though the major nutrients were invariably applied, the micro nutrients were invariably ignored. Moreover, with industrialization, the agricultural labour decreased and maintenance of farm animals become more and more difficult. This resulted in reduced availability of farm yard manure and its application to the crops went on decreasing. Thus, micronutrient deficiencies have started manifesting in most crops. Without the application of micronutrients the response to the major nutrients cannot be obtained since micronutrients affect directly many plant processes. Micronutrient deficiencies have been observed in potato in many locations and it has been found to respond to its application. The critical content of micronutrients in soils and plants have been established. Micronutrients also affect tuber quality. As regards method and time of application micronutrients, the most affective method considering the source has to be adopted.