Phyllosticta leaf spot on Impatiens

Description: Three impatiens in pots were submitted showing leaf spots. The leaf spots occurred randomly on the plants and showed concentric rings with or without a dark purple halo.





Possibilities: Here is a nice article (.pdf/pg 3) showing various leaf spots on impatiens.

Tests done: Moist chamber affected leaves overnight at room temp. to induce sporulation


Results: Pycnidia formed within the rings of the lesions. Botrytis was, of course, also present.


Final diagnosis: Phyllosticta leaf spot caused by Phyllosticta spp.