Black Scurf Disease of Potato and its Management

Potato (Solanum tuberosum) is one of the important food crops after rice wheat and maize. Potato is one of the principal cash crops and contributes to the national economy in many ways. India is amongst five major potato producing countries of the world and it contributes to over 5 % of the world’s production. It is cultivated on 1.2 million hectares which accounts for approximately 0.67% of the total cropped area in India. Total potato production during 2016-17 was 22.1 million tones. It is grown in almost all states. The states Uttar Pradesh West Bengal and Bihar account for nearly 75% of the total area under potato cultivation in India and 82% of the total production. Black scurf disease of potato caused by the fungus Rhizoctonia Solani Kuhn is a serious disease throughout the world. This disease is distributed in India in different regions at different levels of severity and is a major disease problem in fields where potato is cultivated year after year in the same field. In India depending upon growing regions of potatoes the disease causes 25% - 35% yield loss. In addition the black coloured sclerotia present on the surface of the tubers reduces the market acceptability by the consumers. Use of chemicals is also a very common and effective method to control black scurf disease of potato. However the chemical residues are liable to remain on the plant or within its tissues following chemical fungicidal treatment. The report from the US National Academic of Sciences indicating that fungicide residues on food pose a great health risk to the consumer. Thus it is the need of hour to develop new models of fungitoxicants procurable from renewable resources easily biodegradable non toxic and non pollutive. It has already been emphasized that substances of plant origin are largely non toxic to human generally biodegradable and non-pollutive. In this book management of black scurf disease by the extracts of higher plants is discussed in detail. Some new aspe