Informational table showing disease name, symptoms, pathogen/cause, and management of Calceolaria diseases. Disease Symptoms Pathogen/Cause Management Botrytis Blight Leaves, especially those near the soil surface, rot and become covered with gray fungal growth as do fading flowers. Botrytis cinerea Heat and ventilate to maintain low humidity. Remove dead and dying tissue from the greenhouse. Apply a fungicide to protect plants. Phytophthora Root and Crown Rot Crowns and roots have dark brown spots at the soil level. This spreads up the stem as plants wilt and die. Roots are killed. Phytophthora spp. Plant in pasteurized potting mix. Discard infected plants. Apply a fungicide to protect plants.