Pacific Pests, Pathogens and Weeds - Online edition

Pacific Pests, Pathogens, Weeds & Pesticides

Taro root rot (044)

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  • Worldwide distribution. Several types. On taro and Xanthosoma, but also on bean, capsicum, ginger, peanuts and pineapple, and weeds; causes a damping-off disease (see Fact Sheet No. 47). An important disease.
  • A water mould, an oomycete, not a fungus. Worse in wet soils.
  • Roots infected; leaves wilt, become stunted, with only one or two leaves remaining. Corm yields are low; post-harvest rots occur.
  • Cultural control: clean 'tops' of roots and soil; avoid areas that flood, or where water remains for several days; plant on raised beds with surrounding ditches; grow e.g., Mucania or Pueraria before taro to build organic matter content of the soil; add lime (20g/m2) to increase calcium; >3-year crop rotation; collect debris and burn after harvest.
  • Chemical control: none recommended.
Common Name

Taro root rot, cocoyam root rot, Pythium root rot of taro (cocoyam)

Scientific Name

Pythium species

AUTHORS Helen Tsatsia & Grahame Jackson
Information from Jackson GVH, Gerlach WWP (1985) Pythium rots of taro. South Pacific Commission. Noumea, New Caledonia. (; and Ooka JJ (undated) Taro diseases. Research extension series. Hawaii Institute of Tropical Agriculture and Human Resources. Honolulu. Hawaii. (; and from Carmichael A, et al. (2008) TaroPest: an illustrated guide to pests and diseases of taro in the South Pacific. ACIAR Monograph No. 132, 76 pp. (; and from Biosecurity Australia (2011) Review of import conditions for fresh taro corms. Biosecurity Australia, Canberra. ( Photo 3 William Wigmore and Maja Poeschko, Ministry of Agriculture, Cook Islands.

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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