Optimizing growth conditions for Fusarium humuli, the cause of pod rot in black gram (Vigna mungo L. hepper): A study on media, pH, and temperature effects

Black gram (Vigna mungo L. Hepper), a vital crop in South Asia, plays a crucial role in traditional cuisines and sustainable farming practices. Despite its significance, black gram faces challenges from various diseases, with pod rot caused by Fusarium spp. emerging as a recent concern. This study aims to identify the Fusarium species responsible for pod rot in Pantnagar, Uttarakhand, India, through morphological and molecular assays, and to investigate its optimal conditions.The mycelial growth and sporulation of the identified pathogen were examined across eight different culture media, with pH levels ranging from 4.0 to 8.0, and varying temperature levels from 0°C to 40°C. A Fusarium isolate was obtained from symptomatic black gram pods and identified as a member of the Fusarium incarnatum-equiseti species complex. Subsequent molecular analysis confirmed its similarity to F. humuli. Among the culture media tested, Potato Dextrose Agar proved to be the most effective. pH studies revealed that the pathogen thrived best at pH 6.5 and 7.0, while temperatures of 28°C were optimal for both growth and sporulation. These findings provide insights into the environmental factors influencing Fusarium spp. pathogenicity, thereby guiding future studies and disease management strategies.