Pacific Pests, Pathogens and Weeds - Online edition

Pacific Pests, Pathogens, Weeds & Pesticides

Taro corm rots - post-harvest (179)


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Summary
  • Worldwide in the tropics, on many crops. Important diseases.
  • Fungi, water moulds (oomycetes) and bacteria cause the rots. They enter corms at harvest when suckers are broken off. The common ones are: (i) Athelia – pink with white border; (ii) Pythium - white crumbly rot; (iii) Phytophthora taro leaf blight - firm brown rot; (iv) Lasiodiplodia - black, spongy, sour-smelling rot; and (v) Erwinia - soft rot.
  • Cultural control: harvest, remove suckers and soil, and store in (i) leaf-lined soil pit, or (ii) plastic bags or (iii) plastic-lined cardboard boxes, if for markets.
  • Chemical control: improve storage in plastic bags by first dipping corms in bleach (1% for 1-2 mins).
Common Name

Taro corm rots (post-harvest)

Scientific Name

The following are the commonly recorded rots that develop in taro corms after harvest:

Athelia rolfsii (see Fact Sheet no. 11)
Lasiodiplodia (Botryodiplodia) theobromae
Pythium splendens
Phytophthora colocasiae (see Fact Sheet no. 14)
Erwinia species: Erwinia carotovora subsp. carotovora (see Fact Sheet nos. 101, 214, 289, 296); now renamed Pectobacterium carotovorum subsp. carotovorum, and
Erwinia crysanthemi.


AUTHOR Grahame Jackson
Information from and from Biosecurity Australia (2011) Review of import conditions for fresh taro corms. Biosecurity Australia, Canberra. (https://www.agriculture.gov.au/sites/default/files/sitecollectiondocuments/ba/plant/2011/taro/Review_of_Import_Conditions_for_Fresh_Taro_Corms_clean.pdf); 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. (https://lrd.spc.int/about-lrd/lrd-project-partners/taropest).

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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