Spinaciaoleracea, is one of the most important leafy vegetable consumed and cultivated in Southern India.Spinacia (Spinaciaoleracea L.), commonly known as ‘garden spinach’ is one of the cheapest, most accepted and commercially cultivated leafy vegetable. It comes under the family Chenopodiaceae. It has a very good nutrient value and is rich in Vitamin K, A and C, as well as folate, manganese, magnesium, iron, potassium and calcium. It's also a good source of niacin, zinc, protein, fiber, vitamin E, thiamin, vitamin B6, phosphorus and copper. It is a well-known fact that crop yield has to increase to meet the expanding demand for food, feed and bio-energy, caused by world population growth and increasing wealth. One of the most common disease affecting this plant is Downy Mildew, which is caused by the fungus like plant pathogen Peronosporafarinosa, which belongs to the family oomycete.Itis said to be the most economically important spinach disease.