310 INTRODUCTION The apple (Malus x domestica Borkh.) was frst cultivated in Himachal Pradesh in the late 1900s (Singh et al, 2022a). Commercial apple production provided prosperity to its producers and a fnancial windfall to the state, earning it the moniker Apple state of India. Apple farming is carried out on 1,12,630 hectares (Singh et al, 2022b) and the main source of income for farmer families, as well as for others employed in the industry as workers, transporters, middlemen, retailers, and so on. In 2017-18, Himachal Pradesh produced 4, 46,570 MT of apples, with an average productivity rate of 3.96 MT/ha (NHB, 2018). However, in comparison to other parts of the world, this state’s apple production per unit area is poor. The occurrence of numerous diseases, as well as other factors such as bad quality material, insufcient technology, improper inputs, insufcient cooling units, changing climate, and so on, have all been major roadblocks to achieving the necessary output. Fungus, bacteria, viruses, and other microbes produce a variety of diseases that cause both immediate and long-term damage. Thakur (2008) reported that these diseases lead to 30-40% reduction in total yield. Root rot in the 1960s (Agarwala, 1961) which killed 10-15% of apple Prevalence of Stem Black Canker of Apple In Himachal Pradesh Kirtipal Singh 1 , Jagan Nath Sharma 1 , DP Bhandari 2 and Bhupesh Kumar Gupta 1 Department of Plant Pathology, Dr YS Parmar University of Horticulture and Forestry, Nauni, Solan, Himachal Pradesh 173230, India ABSTRACT Coniothecium chomatosporum causes stem black canker is among the most important apple canker diseases, causing widespread losses in apple production. Occurrences of stem black canker were observed in the Kinnaur, Kullu, Mandi, Sirmaur, and Shimla districts of Himachal Pradesh, at elevations ranging from 1000 to 2500 meter above mean sea level (a.m.s.l.) during the regular canker development season, from May to December in 2017 and 2018. The incidence of stem black canker was maximum (38.32%) at Nihri followed by Janjheli (30.93%) of Mandi district, whereas disease was totally absent in some places namely, Narkanda, Rohru and Sarahan. Percent disease index of stem black canker was maximum in Nohradhar (14.22%) followed by Karsog (13.23%) in Mandi district, while minimum percent disease index (0.00%) was at Narkanda and Rohru. The mean overall percent disease index of stem black canker ranged from 0.00 to 14.22 per cent during 2017 and 2018 crop seasons. Key Words: Stem Black, Canker, Apple, Himachal Pradesh, Disease Incidence, Percent Disease Index trees each year. From the late 1980s onwards, apple scab epiphytotics (Gupta, 1978). Similarly ,Gupta and Sharma (1995) reported losses of Rs. 1.5 crores with this disease and Marssonina blotch, which generated misery via early defoliation in the late 1990s (Sharma and Sharma, 2012), has been a source of concerned for the state’s apple growers. In the 1970s, the state had a simultaneous outbreak of cankers (Agarwala and Gupta, 1971). Cankers wounds increase surface area from season to season and are localized lesions on a stem or branch that cause the sloughing away of plant. Thirteen diferent cankers were reported from Himachal Pradesh by Sharma and Sharma (2012) but there is yet no status update on the severity of individual pathogen associated with canker disease with diferent apple growing areas. The distribution patterns of stem black canker have been studied in numerous apple growing districts in Himachal Pradesh. Such information could be useful in determining the true state of the disease and its economic consequences. Furthermore, the distribution trends of stem black canker revealed in this survey would advise apple growers about canker resistant varieties to be transplanted in diferent elevations and geographic areas across the state. Author’s Email kirtipaljat@gmail.com 2RHRTS and KVK, Dr YS Parmar University of Horticulture and Forestry, Sharbo, Kinnaur, Himachal Pradesh 172107, India J Krishi Vigyan 2022, 11 (1) : 310-314 DOI : 10.5958/2349-4433.2022.00148.9 J Krishi Vigyan 2022, 11 (1) : 310-314