IPM Information

Pathology Information:

Species Name: Alternaria tenuis Nees


Yellow, dark brown to black circular leaf spots in concentric rings found on leaves.

Overwinters as mycelium/spores in infected plant debris. Spores may be disseminated during rains to susceptible plant when they germinate directly through wound. Forms conidia that are further spread to cause infection

Control methods:
Apply systemic fungicide to affected trees. Use resistant trees when planting

Growth stage: Mature tree

Disease name: Alternaria leaf spot

Synonym: Alternaria alternata (Fr.) Keissl.

Host name: Alnus nepalensis

Host common name: Nepalese Alder

Affected part: Leaves