Apple Powdery Mildew

Apple Powdery Mildew / Podosphaera leucotricha

Potted apple plants are used for the experiments. The severity and frequency of infestation are recorded at the beginning and end of the test. The growing shoots are treated and assessed on a weekly basis. After approximately 5 weeks, the number of infected leaves and the area of leaves affected by powdery mildew are recorded one last time. By calculating the area under the disease-progress curve (AUDPC) and comparing it to the untreated control, it is possible to determine the efficacy of the test agent against the pathogen.