Smudge of Allium species
Colletotrichum dematium f.sp. circinans
Description:A fungal disease that starts as small greenish spots on the Onion before harvest. During storage these become black and the Onion may shrink and sprout.
Species Affected:Allium species.
Chives, Garlic, Leeks, Onions and Shallots.
White Onions are susceptible and most brown Onions are resistant.
Biology:Favoured by moist conditions around harvest and in storage.
Spores are spread by wind.
Carried on plant debris from previous crops.
Life Cycle:Origin and History:
Management and Control:
Don't continuously crop to White Onions.
Protect Onions from rain after harvest and cure them promptly.
Grow brown skinned varieties if the disease persists.
Destroy crop debris.
Related and Similar Species:References:
Collated by HerbiGuide. Phone 08 98444064 or www.HerbiGuide.com.au for more information.