Survey on Alternaria leaf blight of isabgol incited by Alternaria alternata in major growing areas of Rajasthan

The Alternaria leaf blight disease of (Plantago ovata) isabgol is the new emerging plant disease, causing significant damage to crops. Recognizing its impact, a survey was conducted in the major growing areas of isabgol in Rajasthan during rabi season 2022-23 and 2023-24. The survey conducted in various districts of Rajasthan revealed an average disease intensity of 24.03%, with Bikaner reporting the highest intensity (22.82%) followed by Jaisalmer (19.30%), and the lowest recorded in Barmer (11.67%). Further examination in Bikaner district during the Rabi seasons of 2022-23 and 2023-24 indicated fluctuating disease intensity ranging from 23.86% to 21.77%. Maximum disease intensity (29.07%) occurred in isabgol fields in Ridi village, Shri Dungargarh tehsil, Bikaner, while minimum intensity (17.63%) was observed in Barsingsar village, Bikaner. In Jaisalmer, disease intensity ranged from 20.28% to 18.32%, with Moolana village reporting the highest (23.20%) and Keeta village the lowest (14.96%). Barmer exhibited an average disease intensity of 12.46% to 10.87%, with Gadario ki Dhani village (14.67%) in Gudha Malani tehsil showing the highest intensity at Nosar village (8.68%) and in Baytoo tehsil the intensity was recorded lowest.