Cultural and physiological variation among isolates of Fusarium udum (Butler) causing wilt of pigeonpea

The fourteen isolates of Fusarium udum (Butler) were studied for their discernible characters such as the colour of mycelium, pigmentation of substrate, type and amount of mycelia growth, sporulation, virulence and nutritional requirement. All the isolates were found to be pathogenic though they differed in the per cent disease incidence. The isolate DHO was highly virulent as compared to other isolates. The mycelial growth of 14 isolates of Fusarium udum (Butler) on Czapek’s dox agar basal medium with different carbon, nitrogen sources, temperature and pH varied.