INTRODUCTION Chickpea (Cicer arietinum L.), is one of the most important leguminous crops grown all around the world (Knights et al., 2007). Initially, it was cultivated in South Eastern areas of the world but now it is distributed in semi-arid regions to (Agarwal et al., 2012). It is a major source of dietary protein for human consumption. It also plays an important role in the management of soil fertility because of having the ability of nitrogen fixation in its root nodules (Hossain et al., 2010). There is a growing demand of chickpea due to its nutritional value. It is the better source of carbohydrates and proteins several vitamins and minerals (Chibbar et al., 2010) and also free of cholesterol and provides several vitamins and minerals (Wood and Grusak 2007). The area under cultivation, production and productivity of chickpea in India comprised 6.63 Mha, 9.38 MT and 974 kg/ha, respectively during 2016-17(Anonymous, 2018). In India the major producing states are Madhya Pradesh, Rajasthan, Maharashtra, Uttar Pradesh, Karnataka and Andhra Pradesh together contributing to 90% of the area and 91% of production in the country (Singh, 2010). Madhya Pradesh covers 3.59 M ha area with a production of 4.595 Mt and an average productivity of 1280 kg/ha which is the highest among different pulse crops (PC Annual Report, 2018). Chickpea can be grown in both tropical and temperate regions. Chickpea is known to be affected by many biotic and abiotic constraints that contributed in reduction of average yield in different regions. Among the biotic constraints more than 50 diseases have been reported. Nearly 172 pathogens have been reported so far that infect chickpea (Cicer arietinum L.) in different parts of the world but only a few of them have the potential to devastate the crop (Nene et al., 1996). Collar rot disease caused by Sclerotium rolfsii is a serious threat to chickpea that may cause 55 to 95 % mortality (Shrivastava et al., 1984). It has been reported that collar rot is more severe and most frequently at high moistures and high temperatures conditions (Al Askar et al., 2013). Diseases mostly appear in the early growth stage of the crop particularly before pod formation. Affected younger seedlings turn yellow and may collapse, but older seedlings may dry without collapsing. If affected seedlings are uprooted from moist soil in the earlier stages of infection, rapeseed-like sclerotia can be seen. The yellowing of leaves and constriction at the collar region with white mycelial strands of Sclerotium rolfsii, attached around the collar region are major characteristic symptoms of disease (Nene et al., 2012). We all know, crop in fields are always exposed to multiple biotic and abiotic stresses where plants exhibit certain physiological and molecular responses that interact and have impact on each other to exert the combined effect of these stresses (Choi et al., 2013; Padaria et al., 2015; Pandey et al., 2015). These stress interactions in plants may either have direct or indirect effect on pathogens through other community interactions (Sharma and Ghosh 2017) leading to either positive or negative effects on plant responses (Ramegowda et al., 2013). The on-going changes in climatic conditions such as increase in CO2 emissions, unpredicted rainfall patterns, temperature rise, decrease/increase in relative humidity, and low soil moisture stress (Zhao and Running 2010) are likely to influence the plant diseases establishment, its distribution and epidemiology (Graham and Vance 2003). It is being noticed that Collar rot incidence seems to be increased recent time. Looking to the facts, an intensive survey was carried out to know the present status of Collar rot of chickpea with respect to different agro climatic zones of Madhya Pradesh. MATERIALS AND METHODS A. Survey for disease incidence During Rabi 2018 and 2019, an intensive survey covering 15 districts under 5 agroclimatic zones was carried out to assess the occurrence of collar rot of chickpea (Table 1). The survey was conducted using the GPS location point. In each field 1 m2 area was randomly selected at the 4 different location in the field and average percent mortality was calculated. Percent disease incidence was calculated by using the following formula: Isolation and confirmation of Pathogencity of Isolates. During Rabi 2018 - 2019 collar rot infected chickpea plant samples were collected and washed in distilled water. The fungus was isolated by tissue segment method (Rangaswamy and Mahadevan 1998) under aseptic conditions. The infected tissues were cut into small pieces of 1-2 mm size and surface sterilized with 1% sodium hypochlorite solution for one minute and wash repeatedly thrice in sterile distilled water. These pieces were transferred to blotting paper to remove water adhered to sample and place in Petri plates containing sterilized PDA and incubated at 28 ± 2°C Based on typical cultural cultural characteristic and sclerotial formation pattern, the pathogen is identified as Sclerotium rolfsii. (Barnett and Hunter 1972). RESULT AND DISCUSSION The results obtained from the present investigation are summarized below: Survey for disease incidence. Survey during Rabi 2018 and 2019 revealed that incidence ranged from 11.11% to 10.13%. Plants were assessed for disease based on their visual symptoms on plant and white mycelial growth at collar region (Plate 2) along with Sclerotia (mustard like) were also observed. Collar rot was prevalent in all surveyed agroclimatic zones are presented in Table 3 to 8. Identification of pathogen. The pathogen isolated from typical infected plants was produced white colony on PDA (Plate1). The growing pathogenic fungus was fast as it covered 90 mm petridish within 5 days of inoculation. The growing pattern of colony was submerged and fluffy. Sclerotial formation started after 8-10 days of inoculation. Initially it appeared as white dots and later with in 5-10 it matured. The colony of sclerotia was brown with irregular and round shape. Till 21 days of inoculation numerous sclerotia was formed in the culture plate. This kind of cultural and sclerotial characteristics was observed in Sclerotium rolfsii and several researchers have been reported such kind of standard characteristic of Sclerotium rolfsii (Sarma et al., 2002; Adandonon et al., 2005; Palaiah and Adiver 2006; Okereke and Wokocha, 2007; Akram et al., 2008; Rakholiya and Jadeja 2011; Sharma et al., 2013). Survey in the Central Narmada valley agro climatic zone during 2018 revealed that collar rot incidence ranged from 8.08 to 17.20 percent (Table 2). Highest incidence of 17.20 percent was recorded in the Gadarwara block of Narsinghpur district in the varieties viz. JG 63, RVS 202, RVS 203, JG 36 and the lowest incidence of 8.08 percent was observed in the Gotegaon block of Narsinghpur district in the varieties JG 12, JG 315, JG 63, RVS 202. In Central Narmada valley agro climatic zone during 2018 average incidence of collar rot of chickpea was 10.54 percent. During survey of major Chickpea growing districts of Madhya Pradesh collar rot appeared at 15 - 45 days old crop and it ranged from 5 - 30 percent (Gupta and Mishra 2009). In the Kymore Plateau and Satpura Hills agro climatic zone during 2018 collar rot incidence ranged from 9.30 to 14.80 percent (Table 3). Highest incidence of 14.80 percent in the Rampur Naikin block of Sidhi district in the varieties viz., JG 11, JG 12, JG 130, JG 14, JG 315 and the lowest incidence of 9.30 percent was seen in the Kundam block of Jabalpur district in the varieties JG 315, JG 130. Average incidence of collar rot of chickpea recorded was 12.25 percent in Kymore Plateau and Satpura Hills agro climatic zone during 2018. During survey of major Chickpea growing districts of Madhya Pradesh collar rot appeared at 15 - 45 days old crop and it ranged from 5-30 percent (Gupta and Mishra 2009). The survey in Kymore Plateau and Satpura Hills agro climatic zone during 2019 collar rot revealed incidence ranged from 13.00 to 16.66 percent (Table 4). Highest incidence of 16.66 percent in the Raipura block of Panna district in the varieties viz. JG 11, JG 14 and the lowest incidence of 13.00 percent in the varieties JG 11, JG 130, JG 14 was observed in the Panna block of Panna district. In Kymore Plateau and Satpura Hills agro climatic zone during 2018 average incidence of collar rot of chickpea recorded was 14.41 percent. In Vindhyan Plateau agro climatic zone climatic zone during 2019 survey revealed collar rot incidence ranged from 12.00 to 18.20 percent (Table 5). Highest incidence of 18.20 percent was observed in the Batiyagarh block of Damoh district in the varieties viz. JG 12, Khajwa (Local), JG 16, JG 36. Lowest incidence of 12.00 percent was observed in the Khurai block of Sagar district in the varieties JG 16, JG 322 JG 315, RVS 202. In Vindhyan Plateau agro climatic zone agro climatic zone during 2019 average incidence of collar rot of chickpea recorded was 16.41 percent. During survey of major Chickpea growing districts of Madhya Pradesh collar rot appeared at 15 - 45 days old crop and it ranged from 5 - 30 percent (Gupta and Mishra, 2009). In Northern Hill Region agro climatic climatic zone during 2019 survey, revealed collar rot incidence ranged from 11.76 to 8.10 percent (Table 6). Highest incidence of 11.76 percent was observed in the Dindori block of Dindori district in the varieties viz. JG 315, JG 322, Local. Lowest incidence of 8.10 percent was observed in the Nainpur block of Mandla district in the varieties JAKI 9218, Vijay, JG 130, JG 14. In Northern Hill Region agro climatic zone agro climatic zone during 2019 average incidence of collar rot of chickpea recorded was 10.65 percent. During survey of major Chickpea growing districts of Madhya Pradesh collar rot appeared at 15 - 45 days old crop and it ranged from 5 - 30 percent (Gupta and Mishra 2009). In Satpura Plateau agro climatic zone during 2019, survey revealed collar rot incidence ranged from 11.88 to 9.30 percent (Table 7). Highest incidence of 11.88 percent was observed in the Parasia block of Chhindwara district in the varieties viz. JG 11, JG 12, JG 63 and JG 36. Lowest incidence of 9.30 percent was observed in the Amarwara block of Chhindwara district in the varieties JG 11, JG 130, JG 12, JG 63 and JG 36. In Satpura Plateau agro climatic zone average incidence of collar rot of chickpea recorded was 10.65 percent. During survey of major Chickpea growing districts of Madhya Pradesh collar rot appeared at 15 - 45 days old crop and it ranged from 5 - 30 percent (Gupta and Mishra 2009). Variety wise incidence of collar rot of chickpea observed in different districts. Survey results were also categorized among variety incidence of Collar rot in Madhya Pradesh (Table 8). The chickpea varieties found during the survey of the 15 districts in the 5 agroclimatic zones were JAKI 9218, JG 11, JG 12, JG 130, JG 14, JG 16, JG 24, JG 315, JG 322, JG 36, JG 63, JG 74, JG 14, Khajwa (Local), Rahila (Local), RVS 201, RVS 202, RVS 203, Surya 10, Vijay, Vishal. The highest percent mortality was observed in the variety was observed in Rahila (Local) 12.47 % and the minimum of 9.60 % in the variety RVS 201. During survey of major Chickpea growing districts of Madhya Pradesh collar rot appeared at 15 - 45 days old crop and it ranged from 5 - 30 percent (Gupta and Mishra 2009).