Gummy stem blight or black stem rot attacks stems, leaves, flowers and developing fruit. If severe, it can kill cucurbit plants.

Show all related crops & products


  • Asexual spores (conidia) and sexual spores (ascospores) are produced in small, round, black structures - both can be found on the same lesion
  • Sticky, conidia spores can be dispersed by water splash or on hands / tools during routine crop work
  • Air borne ascospores are key to long-distance dispersal
  • Second cucumber crops are often grown in substrate containing stem bases of previous crop. This tissue can be a source of ascospores - posing a risk to new crop
  • Fungus survives as dormant mycelium or chlamydospores (resting spores) 

Damage caused

  • Caused by the fungus Stagonosporopsis cucurbitacearum (syn. Didymella bryoniae), this pathogen primarily attacks stems and leaves of cucurbits
  • Severe infection can kill the plant
  • Also infects flowers and developing fruits, causing fruit end rot – which can appear after harvest 


Fast and accurate scouting, personalised IPM advice.

The Crop-Scanner App is ready to increase your scouting efficiency! The Crop-Scanner App is available in Belgium, France, the Netherlands, Morocco, the UK, Canada and the USA. Other countries will follow soon.

Get in touch

Contact Biobest