Cocoa bud rot or Cocoa black rot (Phytophthora palmivora)
It is a foot rot disease caused by the fungus (Phytophthora palmivora) which results in large pod losses in West Africa and stem canker in Trinitario populations.
Cocoa bud rot attacks the whole plant. On pods, the disease begins with a circular brown lesion that enlarges to cover the whole pod. It eventually becomes black and mummified, and sometimes covered in a white mass of fungal growth (sporangia). Stem cankers are characterised by oval to round, rusty-brown discolouration of the external bark that looks purple when scraped. Attack of young shoots results in die-back.
Regular harvesting plays the greatest role, as it reduces spread to other pods and bark where stem canker and flower cushion infections may develop.
- Harvest pods regularly and remove diseased pods.
- Thin canopy to improve airflow and reduce humidity.
- Space planting in well drained sites.
- Avoid infested soil.