Pacific Pests, Pathogens and Weeds - Online edition

Pacific Pests, Pathogens, Weeds & Pesticides

Tomato Phytophthora root & fruit rot (157)

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  • Worldwide distribution. On tomato, passionfruit, bele (Fiji). Note, that the oomycete (the water mould is not a fungus) causes a similar disease on capsicum, citrus, papaya, pineapple and tobacco.
  • Roots and lower stems are attacked and plants wilt. Low-hanging fruit show greyish-green rots; at first, the skin stays firm; later, soft rots develop.
  • Spread occurs in rain splash, surface water, and long distance in soil on machinery, tools, and shoes.
  • Cultural control: avoid poor soil drainage; plant on ridges or raised beds; use mulches; remove infected fruit; use a 4-year crop rotation.
  • Chemical control: copper, chlorothalonil, or mancozeb (protectants), metalaxyl (systemic). Spray when fruit third of final size.
Common Name

Phytophthora root & fruit rot, buckeye rot

Scientific Name

Phytophthora nicotianae; previously, Phytophthora parasitica var. nicotianae

AUTHOR Grahame Jackson
Information from Gerlach WWP (1988) Plant diseases of Western Samoa. Samoan German Crop Protection Project, Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) Gmbh, Germany; and (with Photo 1) Diseases of vegetable crops in Australia (2010). Editors, Denis Persley, et al. CSIRO Publishing.

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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