Cercospora Leaf Spot -- Cercospora spp.
Host: Cordyline, dracaena, ficus, hosta, hydrangea, pansy, pittosporum, succulents
Symptoms: Cercospora leaf spot on some foliage plant hosts appears as tiny, slightly raised red or dark green spots that appear on the lower leaf surfaces. On Ti plants rust-colored specks form initially then enlarge into elliptical areas up to 7 mm across and turn tan to brown in color. On pansies, small purplish spots enlarge into conspicuous black spots with fringed margins 1/4 inch or more in diameter. Other symptoms include angular leaf spot.
Conditions Favoring Disease: Cercospora leaf spot is associated with heavy rainfall or with the use of overhead irrigation.
How Pathogen Survives/Disperses: Spores are spread by splashing water. Extended periods of leaf wetness allow spores to germinate and infect the foliage.
Photo and write up provided by Syngenta Professional Products