Studies on various factors influencing growth and pathogenicity of Macrophomina phaseolina in blackgram

Abstract

Macrophomina phaseolina is the most devastating disease in all the urdbean growing districts of Tamil Nadu. An experiment was conducted to study the influence of temperature and pH on the growth of three isolates of M. phaseolina collected from major urdbean growing areas of Tuticorin district. Among the three isolates, M. phaseolina isolate 2 was the most virulent isolate. The pathogen grew well at 35 °C and no growth to very minimal growth was observed at 40 °C. The pathogen grew faster at pH 4 and 5 and gradually decreased at pH 6 and 7. Thus this experiment reveals that M. phaseolina grows well in acidic pH (4 and 5) and high temperature at 35 °C.