|Author: ||James W. Lorbeer|
|Keywords: ||Allium cepa (onion), Allium sativum (garlic), Allium ascalonicum (shallot), Allium porrum (leek), Allium schoenoprasum (chives)|
The management of Allium diseases utilizes many principles of plant diseases control.
Resistance to most seed-, soil-, and airborne fungal diseases presently is not available in commercial Allium cultivars.
Crop rotation, soil fumigation, soil disinfestation, and the use of fungicides in seed treatments, seed furrow treatments, transplant dips, and sprays are procedures extensively used, especially for onions.
Crop rotation is used to reduce the inoculum level of many pathogens.
A 3–4 year rotation to lettuce has eliminated the stem and bulb nematode from soils infested by the pathogen.
Soil fumigants control nematode diseases and pink root.
Soil treatment with garlic oils, flooding, and dipping transplant onions in fungicide solutions have been utilized to control white rot.
Seed treatments with fungicides control seedborne Botrytis neck rot, smut, and damping-off diseases.
Seed furrow treatments with fungicides control Fusarium and Pythium damping off and onion smut.
Fungicide sprays control Botrytis and Stemphylium leaf blights, Botrytis flower blight, Alternaria purple blotch, and downy mildew.
Copper and antibiotic sprays may reduce the incidence of bacterial leaf blights and bulb decays.
Undercutting, wind rowing, and/or heating in storage to dry the inside tissues of onion bulb necks prevents Botrytis neck rot.
Onion yellow dwarf virus is controlled by roguing volunteer onions.
Garlic can be infected by over 20 different viruses.
Antisera are used to detect such viruses in garlic.
Infected garlic is destroyed or heat treated to rid the propagative material of the virus.
Onion cultivars resistant to pink root, Fusarium basal rot, and Botrytis brown stain have been reported.
IPM practices are used when applicable.
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