Survey, Cultural Characterization and Morphological Variability of Macrophomina phaseolina Causing Dry Root Rot in Mung-bean

Abstract

Mungbean (Vigna radiata L. Wilczek) is a short-duration pulse crop widely cultivated in tropical and subtropical regions, valued for its high protein content and role in sustainable agriculture. Despite its importance, production is threatened by dry root rot (DRR), a destructive disease caused by Macrophomina phaseolina (Tassi) Goid. The disease is particularly severe under high temperature and low soil moisture conditions, common in semi-arid regions. The study assessed DRR incidence, characterized the pathogen, and evaluated its cultural behavior. Surveys across Bundelkhand reported disease incidence ranging from 21.62% to 29.26%, with the highest occurrence in Naraini. Pathogenicity tests confirmed the virulence of the fungus, with maximum incidence (53.84%) under combined seed and soil inoculation. Cultural studies revealed that Potato Dextrose Agar supported the highest mycelial growth (89.54 mm) and abundant sclerotia production, followed by Richard’s Agar (83.45 mm), while Sabouraud’s Agar showed the least growth (52.98 mm). The pathogen grew optimally at 30°C, showed good growth at 35°C, and poor growth at 15°C. These findings highlight its adaptability to warm climates and provide essential baseline information for designing region-specific management strategies against DRR in mungbean.