Pacific Pests, Pathogens and Weeds - Online edition

Pacific Pests, Pathogens, Weeds & Pesticides

Taro (Leptosphaerulina) leaf spot (318)

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  • Worldwide distribution. On taro, legumes, and many other vegetables, and weeds. A fungal disease of minor importance.
  • Associated with leaf spots or dead areas on a number of hosts, e.g., leaf spots on pepper (capsicum), a target spot on beans, leaf spots and corm rots on taro. On alfalfa, tan leaf spots are surrounded by brown margins, giving an 'eyespot', sometimes with a yellow halo. 
  • Spread in rain and wind, and possibily seedborne.
  • Cultural control: generally no recommendation; however, on alfalfa in the USA, lepto leaf spot is managed by early harvests; avoiding leaving cut plants in the field; crop rotations avoiding forage legumes for 2 years; and resistant varieties.
  • Chemical control: none recommended.
Common Name

Taro (Leptosphaerulina) leaf spot. CABI gives the preferred common name as soyabean leaf spot. In the USA, it causes alfalfa lepto leaf spot. Alfalfa is a forage legume.

Scientific Name

Leptosphaerulina trifolii. Previously known as Sphaerulina trifolii and Leptosphaerulina briosiana.

AUTHORS Grahame Jackson & Eric McKenzie 
Information 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. ( Photo 1 Fred Brooks, University of Hawaii at Manoa, Photos 2&3 (taken by Eric McKenzie), and used in this fact sheet, appeared previously in McKenzie E (2013) Leptosphaerulina trifolii: PaDIL - (

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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