Alternaria cucumerina
cucumber blight
Alternaria brassicae var. nigrescens, Macrosporium cucumerinum, Alternaria loofahae
Asia: India; Europe: Romania; North America: USA; South America: Argentina
Indiana
2025-12-15
fungus
Mexico
Cucurbitaceae family. Main: pumpkin, marrow, cucurbits.
ALTECU
Alternaria cucumerina primarily affects cucurbits causing Alternaria leaf blight. It produces dark, angular to circular leaf spots that can merge, leading to premature defoliation and reduced yield. The fungus survives on infected crop residue and seed, and spreads mainly through wind-blown spores and splashing water under warm, humid conditions.
Crops
Citrullus lanatus
watermelon
uncertain
ALTECU-2, CABI CPC, ALTECU-5, ALTECU-6, ALTECU-7
Watermelon is a known host of Alternaria cucumerina. The pathogen can persist on crop debris and be spread by wind and rain. Seed transmission remains uncertain, as artificial seed infestation has been demonstrated, but natural seed transmission has only been suggested and not confirmed.
No
No standardized seed test was found.
Biological, Chemical, and Cultural
Use resistant varieties. Remove debris, fall plowing, rotate crops. Some fungicide treatments are available.
ALTECU-6
2025-12-15 16:04:45
Farr, DF and Rossman AY 2015. Fungal Databases, Systematic Mycology and Microbiology Laboratory, ARS, USDA. http://nt.ars-grin.gov/fungaldatabases/
Crop Protection Compendium. Wallingford, UK: CAB International. www.cabi.org/cpc.
Rotem, J. (1994). The genus Alternaria: biology, epidemiology, and pathogenicity (pp. ix+-326).
Keinath, A. P., Wintermantel, W. M., & Zitter, T. A. (2017). Compendium of cucurbit diseases and Pests (No. Ed. 2, pp. 228-pp).
Watt, Bruce A. “Alternaria Leaf Blight of Cucurbits.” University of Maine: Cooperative Extension. Cooperative Extension: Insect Pests, Ticks and Plant Diseases, 2013.
Cucumis melo
melon
uncertain
ALTECU-2, CABI CPC, ALTECU-5, ALTECU-6, ALTECU-7
Melon is a known host of Alternaria cucumerina. The pathogen can persist on crop debris and be spread by wind and rain. Seed transmission remains uncertain, as artificial seed infestation has been demonstrated, but natural seed transmission has only been suggested and not confirmed.
No
No standardized seed test was found.
Biological, Chemical, and Cultural
Use resistant varieties. Remove debris, fall plowing, rotate crops. Some fungicide treatments are available.
ALTECU-6
2025-12-15 16:17:44
Farr, DF and Rossman AY 2015. Fungal Databases, Systematic Mycology and Microbiology Laboratory, ARS, USDA. http://nt.ars-grin.gov/fungaldatabases/
Crop Protection Compendium. Wallingford, UK: CAB International. www.cabi.org/cpc.
Rotem, J. (1994). The genus Alternaria: biology, epidemiology, and pathogenicity (pp. ix+-326).
Keinath, A. P., Wintermantel, W. M., & Zitter, T. A. (2017). Compendium of cucurbit diseases and Pests (No. Ed. 2, pp. 228-pp).
Watt, Bruce A. “Alternaria Leaf Blight of Cucurbits.” University of Maine: Cooperative Extension. Cooperative Extension: Insect Pests, Ticks and Plant Diseases, 2013.
Cucumis sativus
cucumber
Uncertain
ALTECU-2, CABI CPC, ALTECU-5, ALTECU-6, ALTECU-7
Cucumber is a recognized host of Alternaria cucumerina. The pathogen is known to persist on crop debris and spread by wind and rain. Seed transmission remains uncertain, as artificial seed infestation has been demonstrated, but natural seed transmission has only been suggested and not confirmed.
No
No standardized seed test was found.
biological, chemical, cultural
Use resistant varieties. Remove debris, fall plowing, rotate crops. Some fungicide treatments are available
ALTECU-6
2025-12-15 16:01:12
Farr, DF and Rossman AY 2015. Fungal Databases, Systematic Mycology and Microbiology Laboratory, ARS, USDA. http://nt.ars-grin.gov/fungaldatabases/
Crop Protection Compendium. Wallingford, UK: CAB International. www.cabi.org/cpc.
Rotem, J. (1994). The genus Alternaria: biology, epidemiology, and pathogenicity (pp. ix+-326).
Keinath, A. P., Wintermantel, W. M., & Zitter, T. A. (2017). Compendium of cucurbit diseases and Pests (No. Ed. 2, pp. 228-pp).
Watt, Bruce A. “Alternaria Leaf Blight of Cucurbits.” University of Maine: Cooperative Extension. Cooperative Extension: Insect Pests, Ticks and Plant Diseases, 2013.
Cucurbita spp.
squash, gourd, pumpkin
Uncertain
CABI CPC, ALTECU-5, ALTECU-6, ALTECU-7
Cucurbita spp. is a known host of Alternaria cucumerina. The pathogen can persist on crop debris and be spread by wind and rain. Seed transmission remains uncertain, as artificial seed infestation has been demonstrated, but natural seed transmission has only been suggested and not confirmed.
No
No standardized seed test was found.
biological, Chemical, and Cultural
Use resistant varieties. Remove debris, fall plowing, rotate crops. Some fungicide treatments are available.
ALTECU-6
2025-12-15 16:19:15
Crop Protection Compendium. Wallingford, UK: CAB International. www.cabi.org/cpc.
Rotem, J. (1994). The genus Alternaria: biology, epidemiology, and pathogenicity (pp. ix+-326).
Keinath, A. P., Wintermantel, W. M., & Zitter, T. A. (2017). Compendium of cucurbit diseases and Pests (No. Ed. 2, pp. 228-pp).
Watt, Bruce A. “Alternaria Leaf Blight of Cucurbits.” University of Maine: Cooperative Extension. Cooperative Extension: Insect Pests, Ticks and Plant Diseases, 2013.
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