Spoilage organisms

A range of microbes can cause postharvest disease on vegetables. Some are bacteria but most are fungi.

Many bacteria and fungi can cause postharvest disease on fruit and vegetables. The most important postharvest pathogens of vegetables are the fungi Alternaria, Botrytis, Fusarium, Rhizopus and Sclerotinia. Erwinia, the cause of soft rots, is the main bacteria affecting vegetables. Bacterial rots are more likely to develop on vegetables than on fruit because they usually have a pH >4.5, which favours bacteria.

Main postharvest pathogens affecting vegetables

Pathogen	Disease	Vegetables affected
Albugo candida	White rust	Asian leafy, broccoli, rocket, spinach
Alternaria alternata, Alternaria spp.	Black rot, Alternaria spot, black spot	Bean, broccoli, cabbage, capsicum, carrot, cauliflower, cucumber, eggplant, onion, pea, squash, sweet corn, sweetpotato, tomato
Aspergillus niger	Black rot	Onion, sweet corn, tomato
Botrytis allii	Neck rot	Onion, shallot
Botrytis cinerea	Grey mould	ANY, but particularly bean, broccoli, cabbage, capsicum, carrot, cauliflower, cucumber, eggplant, lettuce, onion, pea, pumpkin, squash, sweet corn, sweetpotato, tomato
Colletotrichum spp.	Anthracnose	Bean, capsicum, cucumber, eggplant, pumpkin, squash, tomato
Erwinia carotovora, Erwinia spp.	Bacterial soft rot	ANY, but particularly bean, broccoli, cabbage, capsicum, carrot, cauliflower, celery, cucumber, lettuce, onion, pea, potato, pumpkin, spinach, squash, sweetpotato, tomato
Fusarium spp.	Soft rot	Cabbage, capsicum, carrot, celery, eggplant, onion, potato, pumpkin, squash, sweet corn, sweetpotato
Pectobacterium carotovorum	Bacterial soft rot	Asian leafy, lettuce, cabbage, cauliflower
Penicillium spp.	Blue mould	Cucumber, tomato
Pseudomonas syringae, Pseudomonas spp.	Bacterial spot	Asian leafy, bean, broccoli, cabbage, cauliflower, celery, cucumber, lettuce, onion, pea, spinach, squash, tomato
Pythium aphanidermatum	Cottony rot	Bean, beetroot, cucumber
Rhizopus stolonifer	Storage rot, rhizopus rot	Bean, capsicum, carrot, cucumber, eggplant, pea, pumpkin, squash, sweetpotato, tomato
Sclerotinia sclerotiorum	White rot, white mould	Bean, broccoli, cabbage, carrot, cauliflower, celery, cucumber, eggplant, lettuce, onion, pea, pumpkin, squash
Thielaviopsis basicola	Black root rot	Carrot