Phytophthora blight is caused by the soilborne fungus. On carnations, symptom expression depends on infection site. Infections occurring on the basal portion of the stem cause a typical Wilting and collapse of the stem or plant. The fungus may also invade the stem at any point on the plant, causing stem collapse and eventual death of the branch. If the infection is on the upper leaves and stem, blighting occurs. The most common symptom of this disease, however, is a Wilting, collapse, and bleaching of the tips of healthy shoots, which resembles bromide toxicity symptoms. This is a common disease of carnations grown in areas where soil temperatures rise above 25°C in the daytime.
How Phytophthora blight disease causes damage in carnation?
