Pacific Pests, Pathogens and Weeds - Online edition

Pacific Pests, Pathogens & Weeds

Cocoa black pod (006)


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Summary

  • Worldwide distribution. In the tropics. On cocoa, breadfruit, coconut, papaya, and many other crops. An important disease.
  • A water mould, an oomycete, not a fungus. Infects pods of all sizes and colours. Pods are at first brown then black; they rot but stay on the tree. Pods are destroyed in 10 days or less, depending on size.
  • Spread by spores rain-splashed between pods, or from soil onto lower pods on trunks. Spread by flying insects. Ants place soil with spores on pods over mealybugs. Rots on pods grow back causing branch and trunk cankers; spread also on pruning tools, and possibly by rats and bats.
  • Cultural control: light shade; at least 3 m spacing; good drainage; open canopy, chupon (water shoots) removal; rat control; 2-4-week harvest of ripe and black pods; remove empty pods from plantation; use tolerant varieties (e.g., Amelonado); breeders’ lines developed in Papua New Guinea.
  • Chemical control: copper sprays; trunk injections - phosphorous acid.

Common Name

Black pod

Scientific Name

Phytophthora palmivora. It is not a fungus, but an oomycete or a water mould, related to algae.


AUTHORS Helen Tsatsia & Grahame Jackson
Information from End MJ, et al. (Eds.) 2017. Technical guidelines for the safe movement of cacao germplasm. Revised from the FAO/IPGRI Technical Guidelines No. 20 (Third Update, October 2017). Global Cacao Genetic Resources Network (CacaoNet), Bioversity International, Rome, Italy. (https://www.cacaonet.org/fileadmin/templates/CacaoNet/Uploads/publications/Safe_Movement_Guidelines_2017_En.pdf).; and Vanegtern B, et al. (2015) Black pod rot of cocoa caused by Phytophthora palmivora. College of Tropical Agriculture and Human Resources, University of Hawai'i at Manoa. (https://www.ctahr.hawaii.edu/oc/freepubs/pdf/PD-108.pdf); and from CABI (2019) Phytophthora palmivora (cocoa black pod). Crop Protection Compendium). (https://www.cabi.org/cpc/datasheet/40986).

Produced with support from the Australian Centre for International Agricultural Research under project PC/2010/090: Strengthening integrated crop management research in the Pacific Islands in support of sustainable intensification of high-value crop production, implemented by the University of Queensland and the Secretariat of the Pacific Community.

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