Pacific Pests, Pathogens, Weeds & Pesticides - Online edition

Pacific Pests, Pathogens, Weeds & Pesticides

Celery early blight (136)

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Photo 1. Irregular-shaped spots, brown with grey centres, occur on the leaves, and in wet weather develop into a blight.

Photo 2. Irregular-shaped spots, brown with grey centres, some enlarging and joining together.

Photo 3. The spots of Cercospora apii occur on all the leaves and do considerable damage.

Summary

  • Widespread distribution. North and South America, Asia, Oceania. A damaging fungal disease.
  • First, on older, outer, leaves - yellow spots with grey centres, up to 12mm diam., developing into a blight. Later, on the stalks.
  • Spread by rain splash, on wind and on seed. Survival in crop debris and seed.
  • Cultural control: seed treatment: hot water (48°C for 30 min), but only treat seed <3 years’ old; in nursery, use pasteurised or soilless mixes; use wide spacing and raised beds to improve air circulation in field; use drip not overhead irrigation; plough in remains at harvest, or collect and burn.
  • Chemical control: seed - thiram; field – chlorothalonil, mancozeb, copper; or those in strobilurin, DMI (demethylation inhibitor) groups of fungicides, alternating with the first any of the first three.

Common Name

Celery early blight

Scientific Name

Cercospora apii

Photo 4. The individual spots of Cercospora apii have joined together to form a blight which is destroying the leaves.

AUTHOR Grahame Jackson
Information (and Photo 1) from Diseases of vegetable crops in Australia (2010). Editors, Denis Persley, et al.  CSIRO Publishing; and from Gerlach WWP (1988) Plant diseases of Western Samoa. Samoan German Crop Protection Project, Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) Gmbh, Germany; and CABI (2019) Cercospora apii (early blight: celery). Crop Protection Compendium. (https://www.cabi.org/cpc/datasheet/12185); and Chaput J (2000) Identification and management of celery leaf blights. Ministry of Agriculture, Food and Rural Affairs. Ontario. (http://www.omafra.gov.on.ca/english/crops/facts/00-093.htm); and from Kolke ST, et al. (2008)  Celery Early blight. University of California Statewide IPM Program. Agriculture and Natural Resources, University of California. (http://ipm.ucanr.edu/PMG/r104100211.html). Photo 2&3 Jacquie (Wright) Kami, formerly Plant Pathologist, Secretariat of the Pacific Community, Suva, Fiji.

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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