- Angular leaf spot
- Discolored lesions
- Leaf loss
On tree lilacs, leaf spots are brown to black and angular. For this reason, this disease can be mistaken for foliar nematode or bacterial blight. Laboratory diagnosis is necessary to confirm this pest.
This disease has outbreaks during periods of high humidity and moderate temperatures.
Remove and destroy leaf litter and prune out dead branches to reduce overwintering inoculum. Pseudocercospora leaf spots rarely become severe enough to damage the plant. No fungicides have been specifically tested for control of this disease on Japanese tree lilac but other fungicides containing chlorothalonil, thiophanate-methyl and myclobutanil have been found effective on other hosts.
Active Ingredients include: Chlorothalonil, Myclobutanil, Thiophanate-methyl
