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

  • Potato
  • Hydrangea
  • Periwinkle (Vinca)
  • Tomatoes
  • Tobacco plant
  • Zanteschedia
  • Carrot


Remove affected leaves generously.


Control with Mycostop©, a preparation containing the Streptomyces griseovirides bacterium: this colonizes the roots of the plant before Altenaria, among others, can establish itself there.