Kelly Ivors with the Department of Plant Pathology at North Carolina State University presents about the various methods to isolate Phytophthora from stem, root, and leaf of infected plants.
Sample processing starts with isolating from foilage, stems, and fruit using the 'swipe' method. The sample is incubated and then transferred to new agar. Plating can be done with soil dilution, roots, or leaf on PARPH plates and is observed after 3 to 7 days. The sub-culture is transferred and examined at 24 hours and daily thereafter. Observers will look for Coralloid mycelium, sporangia on agar, and rust-colored medium.