Threats

Teratosphaeria leaf Blight/Teratosphearia eppicoccoides

Teratosphaeria leaf Blight/Teratosphearia eppicoccoides
Teratosphearia eppicoccoides

Kirramyces epicoccoides (Cooke & Masse) Rossman & Allen, Phaeophleospora epicoccoides (Cooke & Masse) Crous et al. 1997, Readeriella epicoccoides (Cooke & Masse) Crous & Braun.

Leaf spots

The symptoms caused by Teratosphearia epicoccoides vary depending on the host species and stage of development of the infection. Infection is usually found on older foliage or on the foliage of stressed trees. (Andjic et al., 2019). In Eucalyptus, symptoms of T. epicoccoides infection initially appear as small purple angular leaf spots that are obvious on the top surface of the leaf. These spots then expand and coalesce, eventually covering the entire leaf surface. On the underside of the leaf, lesions turn yellow to yellow-brown and form angular blotches that are defined by leaf veins. A ‘charcoal’ appearance may be observed due to the covering of the underside of the leaf by brown to black spores (Carnegie, 2008; Walker et al., 1992).

 

Teratosphearia epicoccoides rarely causes significant disease but when inoculum levels are high, and plantations are planted off-site or poorly managed and conditions are conducive for infection, T. epicoccoides can cause significant damage resulting in defoliation and tree death (Andjic et al. 2019 & Crous et al, 2019). In Eucalyptus, E. grandis and E. grandis x camaldulensis hybrids are known to be more susceptible to infection be T. epicoccoides (Andjic et al. 2019).

 

 

Teratosphearia epicoccoides infects leaves by penetrating through stomatal pores. This has been observed to occur within 48 hours after inoculation. Spore production occurs on the underside of the leaves where the spore-producing structures form within stomatal cavities (Solis et al. 2021).

Breeding and selection for tolerance against T. epicoccoides is possible but due to it being considered as a weak pathogen, research in management has not been extensively researched.

1987 (Wingfield, 1987)
Kwa-Zulu Natal, Eastern Cape, Mpumalanga, and the Limpopo (Hunter et al., 2011).
There are over 200 reported hosts and those include Eucalyptus grandis and certain Eucalyptus hybrids such as E. grandis x camaldulensis and E. saligna x urophylla.
Eastern Australia (Andjic et al. 2019).

Gallery

Andjic, V., Carnegie, A., Pegg, G., Hardy, G., Maxwell, A., Crous, P., Pérez, C., Wingfield, M. and Burgess, T. (2019). 23 years of research on Teratosphaeria leaf blight of Eucalyptus. Forest Ecology and Management, 443, pp.19-27.

Carnegie, A. (2008). Healthy hardwoods. A field guide to pests, diseases and nutritional disorders in subtropical hardwoods. 1st ed. Brisbane.: Queensland Dept. of Primary Industries and Fisheries.

Hunter, G.C., Crous, P.W., Carnegie, A.J., Burgess, T.I. and Wingfield, M.J. (2011). Mycosphaerella and Teratosphaeria diseases of Eucalyptus; easily confused and with serious consequences. Fungal Diversity, 50 (1). pp. 145-166.

Solís M., Wingfield M.J., Hammerbacher A., & Naidoo S. 2021. Comparison of the infection biology of Teratosphaeria destructans and Teratosphaeria epicoccoides on Eucalyptus. Plant Disease, 106 (7). pp. 1944-1951.

Crous P.W., Wingfield M.J., Cheewangkoon R., Carnegie A.J., Burgess T.I., Summerell B.A., Edwards J., Taylor P.W.J. & Groenewald J.Z. 2019. Foliar pathogens of eucalypts. Studies in Mycology, 94, pp. 125-298. https://doi.org/10.1016/j.simyco.2019.08.001