Vegetative incompatibility and mycelial death of Cryphonectria parasitica detected with a pH indicator

Incorporation of the pH indicator bromocresol green in medium makes mycelial cell death easier to detect and makes it easier to recognize weakly barraging vegetatively incompatible strains of Cryphonectria parasitica. It also aides in detection of cell death caused by antimicrobial agents and mechanical injury. The method should be applicable to other fungi which have the capacity to lower the pH of their medium.