The garlic (Allium sativum L.) is family amaryllidaceae, perennial plant are the most important commercial crop grown all over world and consumed in various forms. These crops are generally grown throughout the country especially China, India, Bangaldesh, Egypt, south Korea, Russian Federation, Ukraine, Spain, Uzbekistan and Myanmar in India is the major growing of the states of Maharashtra, Uttar Pradesh, Orissa, Gujarat, Madhya Pradesh, Haryana, Punjab, Rajasthan, Uttaranchal, Jammu and Kashmir, Bihar andhra Pradesh and Karnataka. Garlic contains at least 33 sulfur compounds, several enzymes and the minerals germanium, calcium, copper, iron, potassium, magnesium, selenium and zinc; vitamins A, B1 and C, fiber and water and also contains amino acids lysine, histidine, arginine, aspartic acid threonine, glutamine, proline, glycine, alanine, cysteine, valine, methionine, isoleucine, leucine, tryptophan and phenylalanine garlic extract is effective against bacteria, fungi, parasites, lower blood pressure, blood cholesterol and blood sugar, prevent blood clotting, protect the liver and contains antitumor properties in humans garlic extracts have exhibited activity against. The garlic crop is cultivated in several countries and susceptible to number of diseases at various stages of plant growth. From different parts of the world, downy mildew, rust, purple blotch; Stemphylium blight, basal rot, have been observed leading to substantial. Apart from reduction in crop yield, the disease also poses harmful effects during harvesting, post harvesting, processing and marketing stages, which lower the quality and export potential of the crops that significantly causes the economic loss of qualitative and quantative. The diseases alter the cropping pattern and also affect the local and export markets. The consistent use of chemicals to control the plant diseases not only poses a serious threat to the environment and mankind but also slowly build up resistance in the pathogens.
