Ganoderma Root Rot Mortality: Managing the Growing Threat to the Tree behind Traditional Agroforestry in Indian Arid Region Ritu Mawar* and Saranya Ranganathan 1 ICAR-Central Arid Zone Research Institute, Jodhpur 342003, India 1 ICAR-Central Arid Zone Research Institute, Regional Research Station, Jaisalmer 345001, India Received: May 2023 Abstract: Last couple of decades have witnessed large-scale mortality of Indian mesquite (Prosopis cineraria (L.) Druce) or Khejri in specific areas of the Indian arid region. It is caused by Ganoderma lucidum, a root rot- causing soil-borne fungi. The disease is more common in sandy soils where trees experience greater moisture and temperature stress during the summers which predisposes them to the fungal infection. The infection spreads from diseased to healthy trees primarily through root-to-root contacts. Movement of injured lateral roots of P. cineraria from infected tree to healthy trees during mechanical ploughing is a common way of infection dissemination. In later stages of infection, the trees weaken and are then often attacked by an insect, Acanthophorus serraticornis, which aggravate the root rot incidence and accelerate the tree mortality. Isolating infected trees from healthy ones by digging a mechanical trench around has been advocated in past as a prophylactic measure. But the scattered distribution of trees in the fields limits adoption of this approach on a large scale and hence alternate approaches need to be developed to minimize the tree mortality. In this paper, we have discussed about symptoms, pathogen, predisposing factors and management strategies of Ganoderma induced tree mortality and also some ongoing studies. Key words: Prosopis cineraria, Ganoderma, root rot, Trichoderma. Indian arid zone occupies about 12% of the geographical area of the country i.e. about 31.8 m ha in seven states of the country. But, nearly 61% of the arid area falls in Rajasthan state alone. This area is typically characterized by erratic annual rainfall (100-350 mm), extremes of temperature (-2°- 48°C), long day sunshine, high wind speed (35-40 km h -1 ) and thus very high evaporative demand. Nearly 41 to 85% of ground water in the region is saline (8-60 ppt) (Bhati, 1995, 1997; Bhati and Faroda, 2001). The principal rain-fed crops include pearl millet, clusterbean, moth bean, cowpea, sesame and sorghum while in irrigated pockets of the region, wheat, mustard, cumin, blond psyllium, onion, garlic and carrot are cultivated. But after the introduction of canal and spread of ground water irrigation, cotton, ground nut, castor and many fruit plants are also being grown in large area (Sharma and Singh, 2014). Annals of Arid Zone 62(3): 185-195, 2023 https://epubs.icar.org.in/index.php/AAZ OPEN ACCESS Edited by Praveen Kumar Vipin Chaudhary K.S. Jadon S.C. Meena R.K. Solanki *Correspondence Ritu Mawar ritumawar1976@gmail.com Citation Mawar, R. and Ranganathan, S. 2023. Ganoderma Root Rot Mortality: Managing the Growing Threat to the Tree behind Traditional Agroforestry in Indian Arid Region. Annals of Arid Zone 62(3): 185-195 https://doi.org/10.59512/aaz.2023.62.3.1 https://epubs.icar.org.in/index.php/AAZ/ article/view/136137