Pacific Pests, Pathogens and Weeds - Online edition

Pacific Pests, Pathogens, Weeds & Pesticides

Cassava grey leaf spot (321)

Click/tap on images to enlarge
  • 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 - ( Photo 3 Valmir Duarte, Universidade Federal do Rio Grande do Sul, featured on 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.

Copyright © 2022. All rights reserved.