Exserohilum Leaf Spot

Exserohilum Leaf Spot: Caused by Exserohilum rostratum, this disease produces round, gray–brown spots with dark margins. As the disease progresses, lesions coalesce, becoming large and irregular, with dark conidia visible in the lesion centers. Exserohilum rostratum is widely distributed across the United States and has a broad host range, affecting numerous plant species, including cannabis.

Exserohilum Leaf spot
Photo credit: Lindsey Thiessen

Distribution Map