Groundnut (Arachis hypogaea L.) is one of the most important oilseed crops of the world and one out of the nine annual oilseed crops of India. India ranks first in area (5 million hectares) and second in production (4.625 million tonnes) in the world. The cultivation of groundnut is increasing day by day in this country. Besides kharif, it is grown in summer season also and gives good yield too. Groundnut oil is considered as stable and nutritive as it contains right proportion of saturated fatty acids viz., oleic acid (40-50%) and unsaturated fatty acid viz., linoleic acid (25-35%). The nuts contain protein (30%), fat (48%) and carbohydrate (15%) besides vitamins and minerals. Groundnut crop is affected by several economically important pathogens such as early leaf spot, late leaf spot, rust, collar rot, aflarot, stem rot, bacterial wilt, root knot. Rust is the major disease cause heavy loss when it is in sever condition. Due to rust there are biochemical changes occur in sugar, amino acid, protein and phenol. Some biochemical component impart the disease resistancy and some are responsible for susceptible nature of crop.