- Narrow distribution. In Papua New Guinea, Solomon Islands and Taiwan, in dry land and swamps. An important nematode disease.
- The nematodes attack roots causing wilts, and invades corms from the base, causing brown, crumbling rots. Healthy parts turn red.
- Spread short distances by swimming or being moved in ground water. Long distance movement in planting pieces ('tops').
- Cultural control: remove roots from the tops, and inspect corm piece; do not plant down slope from previously infected fields; use hot water (51°C for 10 minutes) to establish source of disease-free plants.
- Chemical control: none recommended.
Pacific Pests, Pathogens, Weeds & Pesticides
Taro Hirschmanniella nematode (010)
Photo 1. Early infection of a corm by mitimiti nematode, Hirschmanniella. At this stage, decay is mostly in the outer parts of the corm.
Photo 2. Late symptoms of mitimiti; infection by the nematode, and secondary rot-causing organisms, has caused complete decay of the corm.
Mitimiti disease, Mitimiti corm rot
AUTHORS Helen Tsatsia & Grahame Jackson
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. (https://lrd.spc.int/about-lrd/lrd-project-partners/taropest); and from Bridge J, et al. (1983) Hirschmanniella miticausa n. sp. (Nematoda : Pratylenchidae) and its pathogenicity on taro (Colocasia esculenta). Revue Nematol 6(2): 285-290. (https://horizon.documentation.ird.fr/exl-doc/pleins_textes/pleins_textes_5/pt5/nemato/15584.pdf). Photo 3 Hanny van Megen, Wageningen UR. (www.wgeningenur.nl). Diagram Sailaja K Nematode biology, Physiology and Ecology.
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.