Fungal disease – Alternaria alternata which causes brown spots mainly on the lower leaves of plants.
Also known as:
Alternaria (Altenaria alternata) is a fungal disease whose spores overwinter in the soil on remaining foliage.
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.