Studies on Alternaria blight disease caused by Alternaria solani on brinjal

Abstract:

Alternaria blight, caused by the necrotrophic fungal pathogen Alternaria solani, stands as a major limiting factor in Southern Rajasthan. The present investigation was meticulously designed to assess the natural incidence and severity of this disease through a comprehensive roving survey conducted during the Kharif/Rabi cropping season of 2024-25. The survey covered three geographically distinct and major brinjal-growing clusters in the Udaipur district: Dabok, Menar, and Kaladwas. Data were recorded from five randomly selected fields in each locality, focusing on three key parameters: Leaf Blight Incidence (%), Percent Disease Index (PDI) on leaves, and Fruit Rot Incidence (%). Kaladwas was identified as a disease hotspot, recording the maximum leaf blight incidence of 44.32%, a peak PDI of 16.95%, and a high fruit rot incidence of 27.07%. In contrast, the Dabok region showed moderate disease pressure (31.22% incidence and 11.18% PDI), while the lowest intensity was observed in Menar (21.55% incidence and 7.53% PDI). These results underscore the urgent need for implementing integrated disease management (IDM) practices and educating local farmers on timely fungicidal interventions to mitigate economic losses in the Udaipur region.