P&PDL Picture of the Week for
October 20, 2008

Anthurium

Tom Creswell, P&PDL Director and Plant Disease Diagnostician

Anthurium is a relatively easy to grow tropical plant for the house, however, you may encounter an occasional disease problem. This Anthurium sample has Cercospora leaf spot. The spots start as small discolored areas, increasing to large tan to brown irregular blotches. Close examination with a hand lens shows a olive drab to black areas of “fuzziness” in the lesions where spores are produced under humid conditions. This disease may be difficult to control but removing all dead and spotted leaves and any debris from the pot surface can help. Make sure the plant receives proper water and nutrition and that leaves don’t get wet when watering.

Click image to enlarge

anthurium

Photo 1: Upper and lower leaf surfaces showing Cercospora leaf spots of various ages and sizes.

anthurium close up

Photo 2: Closer view of an individual spot showing the tan to brown discoloration. Note the fuzzy area at the top of the lesion where spores are being produced.

anthurium spot

Photo 3: Close up of a spot with sporulation.

spores on anthurium

Photo 4: Microscopic view of spores.

Purdue Plant & Pest Diagnostic Lab Purdue Cooperative Extension Service