- Worldwide distribution. On tobacco, tomato, eggplant, and weeds. Common but minor fungal disease in Oceania.
- Spots on lower mature leaves at first, moving up plant as season advances. Spots, circular, up to 15 mm diameter, brown, grey or tan, with dark borders, zoned. Centres papery, producing black masses of spores. Spots continue to develop after harvest.
- Spread as airborne or soilborne spores; possibly, seedborne. Survival in trash other crops and weeds.
- Cultural control: remove volunteers; check plants in nursery; avoid overlapping crops; weed; balanced applications of NPK (soil analyses needed); prune infected leaves as soon as spots seen; avoid overhead irrigation; collect, destroy debris after harvest; crop rotation.
- Chemical control: use chlorothalonil, copper, or mancozeb.
Pacific Pests, Pathogens, Weeds & Pesticides
Tobacco frog-eye leaf spot (304)
Photo 1. Round spots with white or pale brown centres caused by tobacco frog-eye leaf spot, Cercospora nicotianae.
Tobacco frog-eye leaf spot
AUTHORS Grahame Jackson & Eric McKenzie
1Information from Graham KM (1971) Plant diseases of Fiji, HMSO, London; and from CABI (2019) Cercospora nicotianae (frog-eye leaf spot of tobacco). Crop Protection Compendium. (https://www.cabi.org/cpc/datasheet/12251). Photo 1 R.J. Reynolds Tobacco Company Slide Set, R.J. Reynolds Tobacco Company, Bugwood.org. Photo 2 Clemson University - USDA Cooperative Extension Slide Series, Bugwood.org.
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.