Stem Rot

  • Symptoms

  • Trigger

  • Biological Control

  • Chemical Control

  • Preventive Measures

Stem Rot

Didymella lycopersici


In a Nutshell

  • Dark sunken spots on the lower part of stalks.
  • Fruits turn black and shrivel.
  • Plant withers.




Black to brown, sunken spots appear on the stalks near the ground. The plant starts to wither. Fruits turn black and start to shrivel up.


Spore cushions appear on the affected spots. The fungus spreads in the population via the spores that are transported through wind and rain. Spores can be stirred up from the soil by precipitation. Hibernation of the fungus takes place in plant residues, transmission via seeding material is also possible.

Biological Control

Remove infected plants as fast as possible. Disinfect poles and tools. Replacing the soil can produce good results.

Chemical Control

Dicloran and Chlorotalonil can be useful to prevent new infections.

Preventive Measures

Avoid contact of leaves with the soil. Remove lower leaves. Water plants in the morning. Water plants only at the base. Ensure diversified crop rotation. Be careful to use only healthy seedling material