Fungal disease – Alternaria alternata which causes brown spots mainly on the lower leaves of plants.

Also known as:
Leaf spot

recognize fungal disease on plants
Alternaria on leaf tobacco plant, photo: R.J. Reynolds Tobacco Company - CC by 3.0 VS

Alternaria (Altenaria alternata) is a fungal disease whose spores overwinter in the soil on remaining foliage.

Affected plants


Remove affected leaves generously.


Control with a biofungicide based on the bacterium Streptomyces griseovirides: this colonizes the root of the plant before alternaria, among others, can establish itself there.