The annual legume cowpea [Vigna unguiculata (L.) Walp.] is also known as black-eyed pea, southern pea, and so on. Stem and root rot of cowpea is caused by M. phaseolina also one of the major factor of decline in cowpea production. Hence, the present investigation was conducted with an objective to assess the prevalence and incidence of stem and root rot disease in different locations of Jaipur district of Rajasthan during 2019 and assess the cultural characters and pathogenic variability among the isolates of M. phaseolina. From the Agronomy Farm at the S.K.N. College of Agriculture in Jobner, Rajasthan, diseased samples were gathered. The hyphal tip approach was used to purify the pathogen after it was isolated from cowpea roots. Seed, soil, and seed + soil inoculation procedures were used to demonstrate the fungus pathogenicity; the seed + soil inoculation technique showed the highest illness incidence. It was determined that Macrophomina phaseolina was the pathogenic fungus. In kharif 2019, a disease survey on cowpea stem and root rot was conducted in the Jaipur district's surrounding areas. From 12.67% (Kalwar, Jhotwara) to 25.67% (Bhojpura Kalan, Jobner), the illness incidence was noted. The M. phaseolina isolates growth characteristics revealed comparable.

Cowpea, disease survey, pathogens, disease incidence

Among the eight different villages of Jaipur district, the maximum per cent disease incidence was recorded 25.67 Percent from Bhojpura kalan in Jobner block (JP1) and lowest 12.67 Percent from Kalwar in Jhotwara block (JP7). It was determined that M. phaseolina was the causative agent of cowpea root rot disease. Hence, Mycelial growth was highest in isolate JP1 (90.54 mm) and the isolate JP7 had the smallest sclerotia size, quantity, and growth (79.34 mm, 152.93, and 70.66 μm). Similar to the present observations Moradia (2011) have found that increasing sclerotial population of M. phaseolina increased the infection of root rot and colonization in groundnut.

Nisha Nitharwal, Mahabeer Singh, Sonali Meena, Shri Kishan Bairwa, Shankar Lal Bijarniya and Harish Kumar Bijarniya (2025). Survey, Cultural Variation and Pathogenicity of Macrophomina phaseolina causing Stem and Root Rot of Cowpea (Vigna unguiculata (L.) Walp.) in Jaipur District of Rajasthan. Biological Forum – An International Journal, 17(1): 107-112.