- Worldwide distribution. In wet tropics. On cocoa and many other trees and shrubs. An important disease when cultural control operations are not done routinely.
- Fungal threads grow along branches, onto leaf stalks and blades, killing the leaves, which remain hanging in place attached by the threads.
- White toadstools occur occasionally in wet weather.
- Spread is by spores, and branches falling from shade trees onto cocoa beneath.
- Cultural control: prune out infected branches, along with the leaves, remove from the plantation, and burn them. Make regular 3-monthly inspections.
- Chemical control: none recommended.
Pacific Pests, Pathogens, Weeds & Pesticides
Cocoa white thread (015)
Photo 1. White threads of Marasmiellus scandens along a branch and then onto leaves. On some of the leaves the fungus follows the leaf margin and also the veins. The old leaves have been killed by fans of white thread growing over them.
Photo 2. Fans of the fungus, Marasmiellus scandens, growing over the underside of leaves. Note that the old leaves, killed by white thread, are held in place by strands of the fungus.
Marasmiellus (Marasmius) scandens
AUTHORS Helen Tsatsia & Grahame Jackson
Information from CABI (2020) Marasmiellus scandens (white thread blight). Crop Protection Compendium. (https://www.cabi.org/cpc/datasheet/32537); CABI (undated) Plantwise Knowledge Bank. (https://www.plantwise.org/knowledgebank/datasheet/32537#SymptomsSection); and from Amoako-Attah L, et al. (2016) White thread blight disease caused by Marasmiellus scandens (Massee) Dennis & Reid on cocoa and its control in Ghana. African Journal of Agricultural Research 11(50): 5064-5070. (https://academicjournals.org/journal/AJAR/article-abstract/786B84F62138).
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.