Pseudocercospora cannabina

Pseudocercospora cannabina is a fungal plant pathogen infecting hemp. Cercospora cannabina was originally found on the leaves of Cannabis sativa in Uganda. Then in 1976, it was renamed as Pseudocercospora cannabina by mycologist Frederick Claude Deighton (1903-1992).

It was found in Ithaca, New York, USA in 2022 causing a Downy mildew on Cannabis sativa plants. It caused most of the crop to be unusable for market purposes. The disease is characterized by chlorotic (no green on leaves) and necrotic lesions producing sporangiophores (a special type of hypha that bears sporangia on the tip) under high humidity.