Variability in Alternaria sp and Management of Alternaria Leaf Spot and Powdery Mildew of Organic Mungbean Vigna radiata L

Abstract

newlinePresent investigation was conducted to study the occurrence and severity of Alternaria leaf spot and powdery mildew pathogens in mungbean, morphological, cultural and pathogenic variability in the A. alternata isolates collected from mungbean and urdbean plants and assessment of crop losses caused by Alternaria leaf spot and powdery mildew and development of sustainable disease management module through organic practices. newlineFrom the survey of mungbean fields around Udaipur district of Rajasthan, it was observed that the severity of Alternaria leaf spot was highest at Sisarma (48.23 mean PDI with 41.65 and 54.82 PDI at flowering and pod formation stage) during 2017, while it was highest at Rajasthan College of Agriculture (44.85 mean PDI with newline39.11 and 50.60 PDI at flowering and pod formation stage) during 2018. Lowest mean disease intensity of 25.72 and 23.41 was observed at Jhallara village with PDI of 21.93 and 19.83 at flowering stage and PDI of 29.50 and 27.00 at pod formation stage during 2017 and 2018, respectively. The severity of powdery mildew disease was recorded maximum (34.79 mean PDI with 25.40 and 44.17 PDI at flowering and pod formation stage) in the field of Rajasthan College of Agriculture during 2017, whereas, it was maximum at Mavli village during 2018 with 35.19 mean PDI and newline23.11 PDI at flowering stage and 42.37 PDI at pod formation stage. The mean PDI was observed lowest at Kalibheet (23.78 mean PDI with 15.16 and 32.41 PDI at flowering and pod formation stage) during 2017 and at Gogunda (26.28 mean PDI with 17.32 and 35.25 PDI at flowering and pod formation stage) during 2018. newlineThe isolates of Alternaria alternata collected from mungbean and urdbean plants were purified and identified under the microscope through morphological characters. Pathogenicity of these isolates of mungbean (MAa- 1, MAa- 2, MAa- 3) and urdbean (UAa- 1, UAa- 2, UAa- 3) was proved and all the isolates were found pathogenic and exhibited significant difference in symptomatology, colony diameter, size, colony