~ 2373 ~ International Journal of Chemical Studies 2019; 7(5): 2373-2378 P-ISSN: 2349–8528 E-ISSN: 2321–4902 IJCS 2019; 7(5): 2373-2378 © 2019 IJCS Received: 16-07-2019 Accepted: 18-08-2019 Prashant Kumar Singh Department of Plant Pathology, College of Agriculture, RVSKVV, Gwalior, Madhya Pradesh, India Jagdish Kumar Patidar Department of Plant Pathology, College of Agriculture, RVSKVV, Gwalior, Madhya Pradesh, India Reeti Singh Department of Plant Pathology, College of Agriculture, RVSKVV, Gwalior, Madhya Pradesh, India S Roy Central Potato Research Station, Gwalior, Madhya Pradesh, India Bhagyashree Singh Department of Plant Pathology, College of Agriculture, RVSKVV, Gwalior, Madhya Pradesh, India Corresponding Author: Prashant Kumar Singh Department of Plant Pathology, College of Agriculture, RVSKVV, Gwalior, Madhya Pradesh, India Occurrence and distribution of black scurf of potato in different districts of Madhya Pradesh Prashant Kumar Singh, Jagdish Kumar Patidar, Reeti Singh, S Roy and Bhagyashree Singh Abstract Rhizoctonia solani Kuhn (Teleomorph: Thanatephorus cucumeris Frank Donk) causing black scurf and stem canker on potato crop is a economically important diseases. The Rhizoctonia disease complex is common and occurs in potato production areas throughout the world. A survey was conducted during Rabi 2015-16 and 2016-17 in the farmer's field of the five districts of Madhya Pradesh viz., Gwalior, Bhind Morena, Shivpuri and Datia to find out the incidence and severity of black scurf of potato. Surveyed results indicated the prevalence of disease at all the surveyed area. Maximum disease incidence and severity was recorded at Sheopur district (25.23 and 13.84% respectively), while minimum disease incidence (45%) was observed at Bhind district (13.81 and 8.17% respectively). At individual localities, the highest mean disease incidence and severity of 36.82 and 18.53 per cent respectively was found at Ajapura, while the minimum disease incidence and severity of 9.28 and 6.24 per cent respectively was found at Sonpura. Keywords: Survey, black scurf, disease incidence and disease severity Introduction Potato (Solanum tuberosum L.) is an annual, herbaceous and dicotyledonous plant belonging to genus Solanum and family Solanaceae, a major vegetable crop of India, grown on an area of 2179 thousand hectares with an annual production of 48605 thousand tonnes (Anon., 2017) [5] . Potato belongs to one botanical species Solanum tuberosum but it comprises of thousands of varieties that vary in their characteristics. Potato’s origin is from South America Andes. Chile and Peru fight over its origin (Anon., 2008) [4] . Potato is exported from India to other countries like, Pakistan (50.2%), Nepal (24.6%), Sri Lanka (10.3%), Maldives and Singapore (Anon., 2011) [7] . In India, the main potato growing states are Uttar Pradesh followed by West Bengal, Bihar, Punjab, Gujarat and Madhya Pradesh. In Madhya Pradesh, potato is covering an area over, 156 thousand hectares with a production of 3134 thousand MT and productivity of 10.06 MT/ha. (Anon., 2017) [6] . Potato crop is having serious and major pathological threats during recent years, soil-borne and seed-borne diseases have turned out to be a major threat to this crop (Ahmad et al., 1995) [3] . Among the various fungal diseases of potato crop, black scurf of potato is a serious disease of worldwide including India and is responsible for 10-25% yield loss in India (Sharma, 2015) [20] , up to 30% the Canada and yield losses up to 50% in other countries, thereby affecting in potato production severely (Banville, 1989; Woodhall et al., 2008 and Keiser, 2008) [10, 25, 13] . The disease causes defacing of tuber with the deposition of sclerotia. As a result, farmers have to bear 5-7% economic loss (Shekhawat, et al., 1993 and Singh and Shekhawat 1994) [21, 22] . This disease is major potential threat to the fast developing seed potato cultivation in Indian plains. It 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 (Khurana et al., 1998; Arora 2011; Arora, 2012) [16, 8, 9] . It is claimed that there is hardly any plant species, which cannot be infected by R. solani. Further, the fungus has worldwide distribution (Ogoshi, 1987) [18] and isolates of R. solani are highly variable in aggressiveness. In Madhya Pradesh, status of black scurf is not documented. This paper reports the results of a wide-scale study undertaken in the major potato-growing districts of Madhya Pradesh to determine the incidence and distribution of the black scurf of potato.