Pacific Pests, Pathogens, Weeds & Pesticides - Online edition

Pacific Pests, Pathogens, Weeds & Pesticides

Cassava grey leaf spot (321)

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Photo 1. Leaf spots, Periconia manihoticola, on cassava.

Photo 2. Leaf spots, Periconia manihoticola, on cassava.

Photo 3. Stalks bearing spores (at the top) of Periconia manihoticola, leaf spot of cassava.

Summary

  • Worldwide. A minor fungal disease of cassava (more important on rubber).
  • Similar to Passalora henningsii (see Fact Sheet no. 95), but affected areas usually larger, more angular, and more often cause death of leaves. 
  • Leaf spots are circular, up to 10 mm diameter, with pale centres and wide brown or purplish borders.
  • Cultural control: none.
  • Chemical control: none. (Chlorothalonil and mancozeb have been recommended against the fungus on rubber.)

Common Name

Casava grey leaf spot

Scientific Name

Periconia manihoticola; a previous name is Haplographium manihoticola.

AUTHORS Grahame Jackson & Eric McKenzie 
Photos 1&2 (taken by Eric McKenzie), and used in this fact sheet, appeared previously in McKenzie E (2013) Periconia manihoticola PaDIL - (http://www.padil.gov.au). Photo 3 Valmir Duarte, Universidade Federal do Rio Grande do Sul, featured on PaDIL - (http://www.padil.gov.au).

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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