Pacific Pests, Pathogens and Weeds - Online edition

Pacific Pests, Pathogens, Weeds & Pesticides

Taro leaf blight (014)

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  • Worldwide distribution. On taro and some other edible aroids. An important disease.
  • A blight caused by a water mould, an oomycete, not a fungus. Leaves die early and corm yields are low.
  • Corm infections occur at harvest, resulting in firm, brown rots.
  • Spread is in wind-driven rain, and 'tops' for planting.
  • Cultural control: isolate gardens, far from those with leaf blight, preferably >500 masl; avoid planting suckers with leaves attached; inspect regularly, and remove infected leaves; harvest when leaves are dry; store corms in plastic bags (or plastic-lined boxes); tolerant (bred) varieties are main method of control.
  • Chemical control: copper, chlorothalonil, or mancozeb (protectants); metalaxyl or phosphorous acid (systemics).
Common Name

Taro leaf blight

Scientific Name

Phytophthora colocasiae

AUTHORS Helen Tsatsia & Grahame Jackson
Information from Jackson G (2020) Taro leaf blight - My 50-year part in its downfall. (; and 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 Gollifer DE, Brown JF (1974) Phytophthora leaf blight of Colocasia esculenta in the British Solomon Islands. Papua New Guinea Agricultural Journal 25: 6-11; and Singh D, et al. (2012) Taro Leaf Blight - A Threat to Food Security. Agriculture 2: 182-203; and Third taro symposium. Edited by Guarino L, et al. (2003) Report of a meeting (technical). Secretary of the Pacific Community. 242 pp; and from Tyson JL, Fullerton RA (2007) Mating type of Phytophthora colocasiae from the Pacific region, India and South-east Asia. Australasian Plant Disease Notes 2: 111-112. Photos 1&6 Brooks FE (2005) Taro leaf blight. The Plant Health Instructor. DOI:10.1094/PHI-I-2005-0531-01. Diagram Vickie Brewster.

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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